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Journal articles on the topic 'Electromechanical Wave Imaging'

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Author: Grafiati

Published: 1 June 2024

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1

Provost, Jean, Vu Thanh-Hieu Nguyen, Diégo Legrand, Stan Okrasinski, Alexandre Costet, Alok Gambhir, Hasan Garan, and Elisa E. Konofagou. "Electromechanical wave imaging for arrhythmias." Physics in Medicine and Biology 56, no. 22 (October 25, 2011): L1—L11. http://dx.doi.org/10.1088/0031-9155/56/22/f01.

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2

Costet, Alexandre, Lea Melki, Vincent Sayseng, Nadira Hamid, Koki Nakanishi, Elaine Wan, Rebecca Hahn, Shunichi Homma, and Elisa Konofagou. "Electromechanical wave imaging and electromechanical wave velocity estimation in a large animal model of myocardial infarction." Physics in Medicine & Biology 62, no. 24 (November 21, 2017): 9341–56. http://dx.doi.org/10.1088/1361-6560/aa96d0.

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3

Zheng, Lu, Hui Dong, Xiaoyu Wu, Yen-Lin Huang, Wenbo Wang, Weida Wu, Zheng Wang, and Keji Lai. "Interferometric imaging of nonlocal electromechanical power transduction in ferroelectric domains." Proceedings of the National Academy of Sciences 115, no. 21 (May 7, 2018): 5338–42. http://dx.doi.org/10.1073/pnas.1722499115.

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The electrical generation and detection of elastic waves are the foundation for acoustoelectronic and acoustooptic systems. For surface acoustic wave devices, microelectromechanical/nanoelectromechanical systems, and phononic crystals, tailoring the spatial variation of material properties such as piezoelectric and elastic tensors may bring significant improvements to the system performance. Due to the much slower speed of sound than speed of light in solids, it is desirable to study various electroacoustic behaviors at the mesoscopic length scale. In this work, we demonstrate the interferometric imaging of electromechanical power transduction in ferroelectric lithium niobate domain structures by microwave impedance microscopy. In sharp contrast to the traditional standing-wave patterns caused by the superposition of counterpropagating waves, the constructive and destructive fringes in microwave dissipation images exhibit an intriguing one-wavelength periodicity. We show that such unusual interference patterns, which are fundamentally different from the acoustic displacement fields, stem from the nonlocal interaction between electric fields and elastic waves. The results are corroborated by numerical simulations taking into account the sign reversal of piezoelectric tensor in oppositely polarized domains. Our work paves ways to probe nanoscale electroacoustic phenomena in complex structures by near-field electromagnetic imaging.

4

Grubb, Christopher S., Lea Melki, Daniel Y. Wang, James Peacock, Jose Dizon, Vivek Iyer, Carmine Sorbera, et al. "Noninvasive localization of cardiac arrhythmias using electromechanical wave imaging." Science Translational Medicine 12, no. 536 (March 25, 2020): eaax6111. http://dx.doi.org/10.1126/scitranslmed.aax6111.

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Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. The 12-lead electrocardiogram (ECG) is the current noninvasive clinical tool used to diagnose and localize cardiac arrhythmias. However, it has limited accuracy and is subject to operator bias. Here, we present electromechanical wave imaging (EWI), a high–frame rate ultrasound technique that can noninvasively map with high accuracy the electromechanical activation of atrial and ventricular arrhythmias in adult patients. This study evaluates the accuracy of EWI for localization of various arrhythmias in all four chambers of the heart before catheter ablation. Fifty-five patients with an accessory pathway (AP) with Wolff-Parkinson-White (WPW) syndrome, premature ventricular complexes (PVCs), atrial tachycardia (AT), or atrial flutter (AFL) underwent transthoracic EWI and 12-lead ECG. Three-dimensional (3D) rendered EWI isochrones and 12-lead ECG predictions by six electrophysiologists were applied to a standardized segmented cardiac model and subsequently compared to the region of successful ablation on 3D electroanatomical maps generated by invasive catheter mapping. There was significant interobserver variability among 12-lead ECG reads by expert electrophysiologists. EWI correctly predicted 96% of arrhythmia locations as compared with 71% for 12-lead ECG analyses [unadjusted for arrhythmia type: odds ratio (OR), 11.8; 95% confidence interval (CI), 2.2 to 63.2; P = 0.004; adjusted for arrhythmia type: OR, 12.1; 95% CI, 2.3 to 63.2; P = 0.003]. This double-blinded clinical study demonstrates that EWI can localize atrial and ventricular arrhythmias including WPW, PVC, AT, and AFL. EWI when used with ECG may allow for improved treatment for patients with arrhythmias.

5

Provost, J., Wei-Ning Lee, K. Fujikura, and E. E. Konofagou. "Electromechanical Wave Imaging of Normal and Ischemic HeartsIn Vivo." IEEE Transactions on Medical Imaging 29, no. 3 (March 2010): 625–35. http://dx.doi.org/10.1109/tmi.2009.2030186.

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6

Melki, Lea, Melina Tourni, and Elisa E. Konofagou. "Electromechanical Wave Imaging With Machine Learning for Automated Isochrone Generation." IEEE Transactions on Medical Imaging 40, no. 9 (September 2021): 2258–71. http://dx.doi.org/10.1109/tmi.2021.3074808.

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7

Konofagou, Elisa E., Jianwen Luo, Deepak Saluja, Daniel O. Cervantes, James Coromilas, and Kana Fujikura. "Noninvasive electromechanical wave imaging and conduction-relevant velocity estimation in vivo." Ultrasonics 50, no. 2 (February 2010): 208–15. http://dx.doi.org/10.1016/j.ultras.2009.09.026.

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8

Provost, Jean, Alok Gambhir, John Vest, Hasan Garan, and Elisa E. Konofagou. "A clinical feasibility study of atrial and ventricular electromechanical wave imaging." Heart Rhythm 10, no. 6 (June 2013): 856–62. http://dx.doi.org/10.1016/j.hrthm.2013.02.028.

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9

Provost, Jean, Alexandre Costet, Elaine Wan, Alok Gambhir, William Whang, Hasan Garan, and Elisa E. Konofagou. "Assessing the atrial electromechanical coupling during atrial focal tachycardia, flutter, and fibrillation using electromechanical wave imaging in humans." Computers in Biology and Medicine 65 (October 2015): 161–67. http://dx.doi.org/10.1016/j.compbiomed.2015.08.005.

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10

Boissiere, Julien, Mathieu Gautier, Marie-Christine Machet, Gilles Hanton, Pierre Bonnet, and Veronique Eder. "Doppler tissue imaging in assessment of pulmonary hypertension-induced right ventricle dysfunction." American Journal of Physiology-Heart and Circulatory Physiology 289, no. 6 (December 2005): H2450—H2455. http://dx.doi.org/10.1152/ajpheart.00524.2005.

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We aimed to assess the accuracy of Doppler tissue imaging (DTI) in detecting right ventricle (RV) dysfunction and electromechanical coupling alteration following pulmonary hypertension (PHT) in rat. PHT was induced by chronic hypoxia exposure (hypoxic PHT) or monocrotaline treatment (monocrotaline PHT). In both PHT models, we observed transparietal RV pressure increase and remodeling, including hypertrophy and dilation. Conventional echocardiography provided evidence for pulmonary outflow impairment with midsystolic notch and acceleration time decrease in PHT groups (21.7 ± 1.6 and 13.2 ± 2.9 ms in hypoxic and monocrotaline PHT groups vs. 28.1 ± 1.0 ms in control). RV shortening fraction was decreased in the monocrotaline PHT group compared with the hypoxic PHT and control groups. Combining conventional Doppler and DTI was more helpful to detect RV diastolic dysfunction in the monocrotaline PHT group (E/Ea ratio = 17.0 ± 1.4) compared with the hypoxic PHT and control groups (11.5 ± 0.7 and 10.2 ± 0.4, respectively). Tei index measured using DTI highlighted global RV dysfunction in the monocrotaline PHT group (1.36 ± 0.24 vs. 0.92 ± 0.05 and 0.86 ± 0.05 in the hypoxic PHT and control groups, respectively). Q-Sm time measured from the onset of Q wave to the onset of DTI Sm wave was increased in both PHT groups. PHT-induced electromechanical coupling alteration was confirmed by in vitro activation-contraction delay measurements on isolated RV papillary muscle, and both Q-Sm time and activation-contraction delay were correlated with PHT severity. We demonstrated that Q-Sm time measured in DTI was an easily and convenient index to detect early RV electromechanical coupling alteration in both moderate and severe PHT.

11

Pernot, Mathieu, Kana Fujikura, Simon D. Fung-Kee-Fung, and Elisa E. Konofagou. "ECG-gated, Mechanical and Electromechanical Wave Imaging of Cardiovascular Tissues In Vivo." Ultrasound in Medicine & Biology 33, no. 7 (July 2007): 1075–85. http://dx.doi.org/10.1016/j.ultrasmedbio.2007.02.003.

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12

Costet, Alexandre, Elaine Wan, Lea Melki, Ethan Bunting, Julien Grondin, Hasan Garan, and Elisa Konofagou. "Non-invasive Characterization of Focal Arrhythmia with Electromechanical Wave Imaging in Vivo." Ultrasound in Medicine & Biology 44, no. 11 (November 2018): 2241–49. http://dx.doi.org/10.1016/j.ultrasmedbio.2018.06.006.

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13

Costet, Alexandre, Jean Provost, Alok Gambhir, Yevgeniy Bobkov, Peter Danilo, Gerard J. J. Boink, Michael R. Rosen, and Elisa E. Konofagou. "Electromechanical Wave Imaging of Biologically and Electrically Paced Canine Hearts in Vivo." Ultrasound in Medicine & Biology 40, no. 1 (January 2014): 177–87. http://dx.doi.org/10.1016/j.ultrasmedbio.2013.08.019.

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14

Melki, Lea, Alexandre Costet, and Elisa E. Konofagou. "Reproducibility and Angle Independence of Electromechanical Wave Imaging for the Measurement of Electromechanical Activation during Sinus Rhythm in Healthy Humans." Ultrasound in Medicine & Biology 43, no. 10 (October 2017): 2256–68. http://dx.doi.org/10.1016/j.ultrasmedbio.2017.06.019.

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15

Grubb, Christopher, Lea Melki, Daniel Y. Wang, James Peacock, Jose Dizon, Hasan Garan, Elisa Konofagou, and Elaine Wan. "CARDIAC RESYNCHRONIZATION THERAPY IN 3D USING ELECTROMECHANICAL WAVE IMAGING: A NOVEL NON INVASIVE ULTRASOUND-BASED IMAGING TECHNIQUE." Journal of the American College of Cardiology 71, no. 11 (March 2018): A443. http://dx.doi.org/10.1016/s0735-1097(18)30984-7.

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16

Temiz, Fatih, Hatice Güneş, and Hakan Güneş. "Evaluation of Atrial Electromechanical Delay in Children with Obesity." Medicina 55, no. 6 (May 30, 2019): 228. http://dx.doi.org/10.3390/medicina55060228.

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Background and Objective: Childhood obesity is one of the worldwide health problems with an increasing prevalence and accompanied by severe morbidity and mortality. It is a serious predisposing risk factor especially for the development of cardiovascular diseases and arrhythmias. Electromechanical delay (EMD) is known to be a predictor for the development of atrial fibrillation (AF). Our study aims to investigate whether EMD, which is a predictor of AF, prolongs in obese children or not. Material and Methods: The study included 59 obese patients aged between 8–18 years and 38 healthy patients as the control group with a similar age and gender. All the individuals underwent transthoracic echo and tissue Doppler echocardiography. Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by tissue Doppler imaging (TDI) and conventional echocardiography. Results: Obese patients had significantly lengthened P-wave on surface ECG to the beginning of the late diastolic wave (PA) lateral, PA septum, intra- and inter-atrial electromechanical delays when compared with the control group (p < 0.001, p = 0.001, p < 0.001 and p < 0.001, respectively) Inter-atrial EMD and intra-atrial EMD correlated positively with body mass index (BMI) values (r = 0.484, p < 0.001 and r = 0.376, p = 0.001; respectively) BMI was significantly related with inter-atrial EMD (β = 0.473, p < 0.001) However, there was no relationship between inter-atrial EMD and serum glucose and platelet count. Conclusion: In our study, we declared that electromechanical delay was increased in obese children when compared to the control group and intra- and inter-atrial electromechanical delay was in correlation with body mass index. Furthermore, we discovered that BMI is an independent predictor of the inter-atrial EMD in obese children.

17

Wan, Elaine, Alexander Costet, Ethan Bunting, Julien Grondin, Elisa Konofagou, and Hasan Garan. "176-22: Electromechanical wave imaging: a novel non-invasive tool for atrial arrhythmia mapping." EP Europace 18, suppl_1 (June 2016): i122. http://dx.doi.org/10.1093/europace/18.suppl_1.i122c.

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18

Grondin, Julien, Alexandre Costet, Ethan Bunting, Alok Gambhir, Hasan Garan, Elaine Wan, and Elisa E. Konofagou. "Validation of electromechanical wave imaging in a canine model during pacing and sinus rhythm." Heart Rhythm 13, no. 11 (November 2016): 2221–27. http://dx.doi.org/10.1016/j.hrthm.2016.08.010.

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19

Provost, Jean, Stéphane Thiébaut, Jianwen Luo, and Elisa E. Konofagou. "Single-heartbeat electromechanical wave imaging with optimal strain estimation using temporally unequispaced acquisition sequences." Physics in Medicine and Biology 57, no. 4 (February 1, 2012): 1095–112. http://dx.doi.org/10.1088/0031-9155/57/4/1095.

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20

Jiang, Xie, Wensong Zhou, Xize Chen, Xin Zhang, Jiefeng Xie, Tao Tang, Yuxiang Zhang, and Zhengwei Yang. "An Electromechanical Impedance-Based Imaging Algorithm for Damage Identification of Chemical Milling Stiffened Panel." Structural Control and Health Monitoring 2024 (May 17, 2024): 1–15. http://dx.doi.org/10.1155/2024/4554472.

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The multiple intersecting stiffeners on the chemical milling stiffened panel (CMSP) limit the application of active health monitoring methods on it. An imaging algorithm based on electromechanical impedance (EMI) and probability-weighting is proposed to achieve quantitative evaluation and localization of the damage on CMSP. The proposed algorithm compensates for the difference in sensor performance with coefficients and there is no need to determine the key parameters of the algorithm through prior experiments. In the paper, the applicability of ultrasonic guided wave (GW) and EMI on CMSP was first studied through the finite element method. Based on EMI and the mean absolute percentage deviation (MAPD), the selected damage indicator (DI), a probability-weighted damage imaging algorithm are proposed and experimentally verified. The results indicate that due to the reflection and attenuation effects of stiffeners on GW, the signal characteristics of damage scattering waves are contaminated, making it difficult to quantitatively characterize the damage from GW signals through DIs. MAPD is positively correlated with the damage degree and has consistency in characterizing the signal of different PZTs under the same working condition. The feasibility and accuracy of the proposed algorithm are verified through experiments which show a strong engineering application capability.

21

Singh, Amandeep, Pawan Kumar, Sriya Yeleswarapu, Falguni Pati, and Renu John. "Surface wave elastography using high speed full-field optical interferometry." Biomedical Physics & Engineering Express 8, no. 2 (February 10, 2022): 025013. http://dx.doi.org/10.1088/2057-1976/ac50be.

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Abstract The assessment of mechanical stiffness is an essential diagnostic tool for investigating the biomechanical properties of biological tissues. Surface wave elastography (SWE) is an emerging technique to quantify elastic properties of tissues in clinical diagnosis. High-speed optical imaging combined with SWE has enormous potential in quantifying the elastic properties of tissues at microscale resolutions. In this study, we implement surface wave elastography using high-speed optical interferometry to characterize the elastic properties of tissue-mimicking phantoms and ex-vivo native caprine liver tissue by imaging the surface wave induced by an electromechanical actuator. The sinusoidal mechanical excitations ranging from 120 Hz to 1.2 kHz on the surface of tissues are captured using a high-speed camera with a frame rate of 4 kHz at micrometer resolutions. The surface wavefront reconstruction is performed using a phase-shifting algorithm and linear regression is used to calculate the surface wave velocity. The mechanical stiffness estimated from the optical system is compared with the results of mechanical compression testing measurements. The results from this multimodal platform combining optical interferometry and vibrational spectroscopy using SWE are highly promising towards a non-invasive or minimally invasive imaging for in-vivo and ex-vivo mechanical characterization of tissues with future clinical applications.

22

BUNTING, ETHAN, LITSA LAMBRAKOS, PAUL KEMPER, WILLIAM WHANG, HASAN GARAN, and ELISA KONOFAGOU. "Imaging the Propagation of the Electromechanical Wave in Heart Failure Patients with Cardiac Resynchronization Therapy." Pacing and Clinical Electrophysiology 40, no. 1 (December 2, 2016): 35–45. http://dx.doi.org/10.1111/pace.12964.

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23

Bessière, Francis, Ali Zorgani, Jade Robert, Loïc Daunizeau, Elodie Cao, Fanny Vaillant, Emma Abell, et al. "High Frame Rate Ultrasound for Electromechanical Wave Imaging to Differentiate Endocardial From Epicardial Myocardial Activation." Ultrasound in Medicine & Biology 46, no. 2 (February 2020): 405–14. http://dx.doi.org/10.1016/j.ultrasmedbio.2019.10.017.

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24

Nauleau, Pierre, Lea Melki, Elaine Wan, and Elisa Konofagou. "Technical Note: A 3-D rendering algorithm for electromechanical wave imaging of a beating heart." Medical Physics 44, no. 9 (July 28, 2017): 4766–72. http://dx.doi.org/10.1002/mp.12411.

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25

Tourni, Melina, Johanna Tonko, Alexandra Channing, and Elisa Konofagou. "PO-05-185 ELECTROMECHANICAL WAVE IMAGING FOR ARRHYTHMOGENIC MITRAL VALVE DISEASE CHARACTERIZATION IN THE CLINIC." Heart Rhythm 21, no. 5 (May 2024): S578—S579. http://dx.doi.org/10.1016/j.hrthm.2024.03.1456.

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26

OSULLIVAN, C., I. RAMZY, D. GIBSON, and M. HENEIN. "195 Diastolic left ventricular electromechanical disturbances in Q-wave myocardial infarction." European Journal of Echocardiography 1 (December 1999): S10. http://dx.doi.org/10.1016/s1525-2167(99)80030-4.

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27

OSULLIVAN, C., I. RAMZY, D. GIBSON, and M. HENEIN. "195 Diastolic left ventricular electromechanical disturbances in Q-wave myocardial infarction." European Journal of Echocardiography 1 (December 1999): S36. http://dx.doi.org/10.1016/s1525-2167(99)80125-5.

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28

Provost, Jean, Viatcheslav Gurev, Natalia Trayanova, and Elisa E. Konofagou. "Mapping of cardiac electrical activation with electromechanical wave imaging: An in silico–in vivo reciprocity study." Heart Rhythm 8, no. 5 (May 2011): 752–59. http://dx.doi.org/10.1016/j.hrthm.2010.12.034.

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29

Wan, Elaine, Alexander Costet, Ethan Bunting, Julien Grondin, Hasan Garan, and Elisa Konofagou. "49-06: Using electromechanical wave imaging, a novel non-invasive ultrasound imaging tool to detect endocardial versus epicardial arrhythmia origins." EP Europace 18, suppl_1 (June 2016): i31. http://dx.doi.org/10.1093/europace/18.suppl_1.i31c.

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30

Nesmith, Haley W., Hanyu Zhang, and Jack M. Rogers. "Optical mapping of electromechanics in intact organs." Experimental Biology and Medicine 245, no. 4 (December 16, 2019): 368–73. http://dx.doi.org/10.1177/1535370219894942.

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Optical mapping has become a widely used and important method in cardiac electrophysiology. The method typically uses voltage-sensitive fluorescent dyes and high-speed cameras to image propagation of electrical waves. However, signals are highly susceptible to artifact caused by motion of the target organ. Consequently, cardiac optical mapping is traditionally performed in isolated, perfused organs whose contraction has been pharmacologically arrested. This has prevented optical mapping from being used to study interactions between electrical and mechanical motion. However, recently, a number of groups have developed methods to implement cardiac optical mapping in the presence of motion. These methods employ two basic strategies: (1) compensate for motion by measuring it or (2) ratiometry. In ratiometry, two signals are recorded from each site. The signals have differing sensitivity to membrane potential, but common motion artifact, which can be cancelled by taking the ratio of the two signals. Some methods use both of these strategies. Methods that measure motion have the additional advantage that this information can be used to quantify the organ’s mechanical function. Doing so enables combined “electromechanical mapping,” which allows optical study of electromechanical interactions. By allowing recording in the presence of motion, the new methods open the door to optical recording in in-vivo preparations. In addition, it is possible to implement electromechanical optical mapping techniques in organ systems other than the heart. For example, it was recently shown that optical mapping of slow wave propagation in the swine stomach is feasible. Such studies have the potential to uncover new information on the role of dysrhythmic slow wave propagation in gastric motility disorders. Impact statement Electrical and mechanical functions in the heart are bidirectionally coupled, yet are usually studied separately because of the different instrumentation technologies that are used in the two areas. Optical mapping is a powerful and widespread tool for imaging electrical propagation, but has traditionally required mechanical function to be arrested. Recently new methods have been devised that enable optical mapping to be performed in beating hearts and also to simultaneously quantify mechanical function. These new technologies promise to yield new information about electromechanical interactions in normal and pathological settings. They are also beginning to find application in other organ systems such as the gastrointestinal tract where they may provide new insight into motility disorders.

31

Yildiz, Abdulkadir, Derya Ucmak, Mustafa Oylumlu, Meltem Z. Akkurt, Murat Yuksel, Mehmet Ata Akil, Halit Acet, Nihat Polat, Mesut Aydin, and M. Zihni Bilik. "Assessment of Atrial Electromechanical Delay and P-Wave Dispersion in Patients with Psoriasis." Echocardiography 31, no. 9 (February 7, 2014): 1071–76. http://dx.doi.org/10.1111/echo.12530.

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32

Costet, Alexandre, Elaine Wan, Ethan Bunting, Julien Grondin, Hasan Garan, and Elisa Konofagou. "Electromechanical wave imaging (EWI) validation in all four cardiac chambers with 3D electroanatomic mapping in caninesin vivo." Physics in Medicine and Biology 61, no. 22 (October 26, 2016): 8105–19. http://dx.doi.org/10.1088/0031-9155/61/22/8105.

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33

Konofagou, Elisa E., and Jean Provost. "Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence in canines and humans in vivo." Journal of Biomechanics 45, no. 5 (March 2012): 856–64. http://dx.doi.org/10.1016/j.jbiomech.2011.11.027.

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34

Melki, Lea, Christopher S. Grubb, Rachel Weber, Pierre Nauleau, Hasan Garan, Elaine Wan, Eric S. Silver, Leonardo Liberman, and Elisa E. Konofagou. "Localization of Accessory Pathways in Pediatric Patients With Wolff-Parkinson-White Syndrome Using 3D-Rendered Electromechanical Wave Imaging." JACC: Clinical Electrophysiology 5, no. 4 (April 2019): 427–37. http://dx.doi.org/10.1016/j.jacep.2018.12.001.

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35

Zhang, Xiaohui, Wei Zeng, Yuanmin Li, Dapeng Hou, Xiuchang Li, and Wenbo Xu. "Evaluation of P wave Dispersion and Tissue Doppler Imaging for Predicting Paroxysmal Atrial Fibrillation in Patients with Hypertension." Heart Surgery Forum 21, no. 1 (February 22, 2018): 054. http://dx.doi.org/10.1532/hsf.1831.

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Background: There are no previous studies dealing with paroxysmal atrial fibrillation (AF) and hypertension using electrocardiogram and tissue doppler imaging (TDI). The aim of this study was to investigate and identify the predictive indicators for paroxysmal AF in hypertensive patients using P wave dispersion (Pd) and TDI.Methods: Patients with hypertension were enrolled. Patients with paroxysmal AF were classified as the PAF group, and patients without a history of paroxysmal AF were classified as the NAF group. The clinical data, P wave indicators and TDI indicators were collected and compared between the two groups.Results: A total of 120 patients were enrolled into the study with 40 cases in the PAF group and 80 cases in the NAF group. Compared with NAF group, Pd, maximum P wave duration (Pmax), left ventricular end-diastolic dimension (LVEDd) and left atrial dimension (LAD) were significantly longer (P < .05) in the PAF group. PAL, PAI, PAR, LR, LI and IR were significantly longer (P < .05) in the PAF group than in the NAF group. As for ROC analysis, Pd and PAL had the greatest area under the curve. The best diagnostic value of Pd and PAL was 40ms and 78ms, respectively. The combination of Pd ≥40ms with Pmax ≥ 110ms showed higher specificity and positive predictive value but decreased sensitivity and negative predictive value for paroxysmal AF.Conclusions: The PAF group had significantly longer atrial electromechanical time and higher Pd compared with NAF group. The combination of Pd and TDI may be helpful to predict the onset of paroxysmal AF in patients with hypertension.

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ÇALAPKORUR, Bekir, Mustafa GÖK, Ömer Faruk BOLATTÜRK, Erkan DEMİRCİ, and Yücel YILMAZ. "Evaluation of strain echocardiography and atrial electromechanical delay in patients with idiopathic carpal tunnel syndrome." Journal of Health Sciences and Medicine 5, no. 5 (September 25, 2022): 1385–89. http://dx.doi.org/10.32322/jhsm.1143836.

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Aim: Carpal tunnel syndrome (CTS) could be an early marker for amyloidosis before developing of overt symptoms of cardiac amyloidosis (CA). CA characterized with left ventricular (LV) diastolic dysfunction and impairment of LV deformation-based parameters. There is limited data about echocardiographic parameters such as strain value of LV, diastolic parameters and atrial EMD in patients with idiopathic CTS. In this study, we investigated LV strain values, diastolic parameters of LV and atrial EMD in patients with idiopathic CTS. Then, we compared these parameters in CTS patients to control group. Material and Method: Thirty-four patients with idiopathic CTS and twenty-four aged and sex matched volunteers were enrolled to study. Patients with known amyloidosis, heart failure, diabetes mellitus and secondary etiologic states for CTS such as trauma or rheumatologic disease were excluded from the study. ECG and echocardiographic examination of each patient were performed and recorded by cardiology specialist. Conventional and strain imaging echocardiography were performed. Atrial electromechanical delays (EMD) were measured. Results: Baseline characteristics features were not different in groups. Mitral inflow velocities (mitral E and A wave), mitral E wave deceleration time, tissue Doppler velocities (lateral annular E’ and A wave), E/A and E/E’ ratios were similar in two groups. Septal basal strain values increased in CTS group (-21.3±4.83% vs -25.7±2.96%, p<0.001). Septal apical to base ratio (SAB) and relative apical sparing (RELAPS) were increased in CTS group compared to control group (0.94±0.43 vs 0.66±0.12, 0.90±0.31 vs 0.73±0.08, p=0.004, p=0.013, respectively). PA lateral, PA septal, inter-atrial EMD and intra-atrial EMD were significantly higher in CTS group compared to control group (78.2±12.3 ms vs 70.6±9.9 ms, 64.1±8.42 ms vs 58.3±10.1 ms, 25.8±9.09 ms vs 20.7±5.31 ms, 11.68±5.11 ms vs 8.46±3.02 ms, p=0.015, p=0.023, p=0.009 and p=.008, respectively). Conclusion: In CTS group, mean basal strain decreased compared to control group. SAB and RELAPS which associate with CA, decreased in CTS group. Atrial EMD prolonged in CTS group. These changes may associate with increased risk of CA and AF in patients with CTS.

37

Syafitri, Rosa, Pintoko Tedjokusumo, and M. Rizki Akbar. "Correlation Between Uric Acid and Atrial Electromechanical Coupling Interval in Heart Failure with Reduced Ejection Fraction." ACI (Acta Cardiologia Indonesiana) 6, no. 1 (March 1, 2020): 34–40. http://dx.doi.org/10.22146/jaci.v6i1.127.

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Background: Chronic Heart Failure (CHF) can lead to atrial and structural remodeling that result in non-homogenous impulse propagation and inter and intra-atrial conduction delay. Prolongation of interval of Atrial ElectroMechanical Coupling (AEMC) in CHF patient was related to atrial electromechanical remodeling and Atrial Fibrillation (AF) risk. Hyperuricemia found in CHF played a role in the pathophysiology of AF through neuro-hormonal activation, oxidative stress, inflammation and ionic channel dysfunction. This study aimed to investigate the association between uric acid and AEMCinterval in CHF with reduced ejection fraction.Methods: This study was a cross sectional study. Subject were CHF patients with reduced ejection fraction and sinus rhythm who visited cardiology clinic Dr. Hasan Sadikin Bandung between July - September 2018. Blood sampling for uric acid was performed in the morning after fasting 10-12 hours. AEMC interval was measured by echocardiography Tissue Doppler Imaging (TDI) as time interval from onset of P wave in surface electrocardiography to onset of A wave from TDI in lateral atrial wall called lateral PA interval. Statistical analysis was done by linear regression analysis to control confounding variables.Results: This study involved 51 CHF patients with reduced ejection fraction (< 40%) with median age 62 (27 – 81) year, 92% have history of myocardial infarction or coronary revascularization, 16% have diabetes mellitus, 51% have hypertension, and eGFR of 60.9 + 22.1. Mean uric acid was 8.0 + 2.2 mg/dL and mean lateral PA interval was 67.4 + 19.2 ms. Uric acid was significantly associated with lateral PA interval (R : 0.665, adjusted R2 0.407, P < 0.001) after controlling the confounding variables: systolic blood pressure and diastolic function.Conclusion: Uric acid significantly correlated positively with AEMC interval in CHF patients with reduced ejection fraction.

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Tascanov, Mustafa Begenc. "The Relationship Between Prolidase Activity and Atrial Electromechanical Changes in Patients with Paroxysmal Atrial Fibrillation." Combinatorial Chemistry & High Throughput Screening 22, no. 1 (May 3, 2019): 69–75. http://dx.doi.org/10.2174/1386207322666190306143317.

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Background:Tissue fibrosis increases in the structure of the atrial tissue of atrial fibrillation patients. Prolidase enzyme regulates collagen synthesis. There may be an association between electrocardiography (ECG) findings and prolidase activity.Objective:This study investigated the association between atrial conduction time and prolidase activity, a collagen synthesis enzyme, and P-wave dispersion (PWD) in patients with Paroxysmal Atrial Fibrillation (PAF).Methods:Exclusion criteria included the age of <18 years, heart failure, diabetes, hypertension, hyperlipidemia, malignancy, cerebrovascular disease, chronic respiratory distress, osteoporosis, rheumatoid arthritis, renal disease, cirrhosis, and other types of arrhythmia. Patients diagnosed with PAF within 48 hours were considered to have a definite diagnosis. PWD was calculated using a 12-lead ECG, and inter- and intraatrial electromechanical delay (EMD) was assessed using tissue Doppler imaging and conventional echocardiography. Serum prolidase levels were measured in both groups.Results:A total of 43 patients with PAF (20 female, 23 male; mean age, 46.8 ± 5.7 years) and 42 healthy volunteers (21 female, 21 male; mean age, 43.9 ± 5.1 years) were included in the study.:Inter- and intraatrial EMD, PWD, minimum P-wave (Pmin), and maximum P-wave (Pmax) measurements were significantly higher (39.7 ± 2.7, 35.7 ± 2.3, p < 0.001; 13.2 ± 2.6, 8.5 ± 1.9, p < 0.001; 47.1 ± 11, 24.1 ± 7.1, p < 0.001; 69.8 ± 8.8, 66.7 ± 10.2, p < 0.130; 114.8 ± 13, 93.6 ± 8.6, p < 0.001, respectively) and serum prolidase levels were significantly lower in patients with PAF compared to healthy controls (3.96 ± 1.2, 8.5 ± 3.56, p < 0.001). In patients with PAF, correlation analysis showed a negative correlation between prolidase levels and intra- and interatrial EMD, PWD, and Pmax (r = -0.41, p < 0.05; r = -0.54, p < 0.05; r = -0.62, p < 0.05; r = -0.49, p < 0.05, respectively). Interatrial EMD showed a significant positive correlation with intraatrial EMD, Pmax, and PWD in patients with PAF (r = 0.90, p < 0.05; r = 0.574, p < 0.05; r = 0.43, p < 0.05, respectively). Additionally, the level of high-sensitivity C-reactive protein (hs-CRP) was significantly higher in patients with PAF (6.6 ± 8, 1.8 ± 1.6, p < 0.001).Conclusion:The decreased plasma prolidase activity in patients with PAF may explain the irregularity of the collagen metabolism of different extracellular components and may indicate the onset of atrial remodeling. Changes in PWD, interatrial EMD, and serum prolidase level may predict PAF before diagnosis.

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Cooper, Leroy L., Katja E. Odening, Min-Sig Hwang, Leonard Chaves, Lorraine Schofield, Chantel A. Taylor, Anthony S. Gemignani, et al. "Electromechanical and structural alterations in the aging rabbit heart and aorta." American Journal of Physiology-Heart and Circulatory Physiology 302, no. 8 (April 15, 2012): H1625—H1635. http://dx.doi.org/10.1152/ajpheart.00960.2011.

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Aging increases the risk for arrhythmias and sudden cardiac death (SCD). We aimed at elucidating aging-related electrical, functional, and structural changes in the heart and vasculature that account for this heightened arrhythmogenic risk. Young (5–9 mo) and old (3.5–6 yr) female New Zealand White (NZW) rabbits were subjected to in vivo hemodynamic, electrophysiological, and echocardiographic studies as well as ex vivo optical mapping, high-field magnetic resonance imaging (MRI), and histochemical experiments. Aging increased aortic stiffness (baseline pulse wave velocity: young, 3.54 ± 0.36 vs. old, 4.35 ± 0.28 m/s, P < 0.002) and diastolic (end diastolic pressure-volume relations: 3.28 ± 0.5 vs. 4.95 ± 1.5 mmHg/ml, P < 0.05) and systolic (end systolic pressure-volume relations: 20.56 ± 4.2 vs. 33.14 ± 8.4 mmHg/ml, P < 0.01) myocardial elastances in old rabbits. Electrophysiological and optical mapping studies revealed age-related slowing of ventricular and His-Purkinje conduction (His-to-ventricle interval: 23 ± 2.5 vs. 31.9 ± 2.9 ms, P < 0.0001), altered conduction anisotropy, and a greater inducibility of ventricular fibrillation (VF, 3/12 vs. 7/9, P < 0.05) in old rabbits. Histochemical studies confirmed an aging-related increased fibrosis in the ventricles. MRI showed a deterioration of the free-running Purkinje fiber network in ventricular and septal walls in old hearts as well as aging-related alterations of the myofibrillar orientation and myocardial sheet structure that may account for this slowed conduction velocity. Aging leads to parallel stiffening of the aorta and the heart, including an increase in systolic stiffness and contractility and diastolic stiffness. Increasingly, anisotropic conduction velocity due to fibrosis and altered myofibrillar orientation and myocardial sheet structure may contribute to the pathogenesis of VF in old hearts. The aging rabbit model represents a useful tool for elucidating age-related changes that predispose the aging heart to arrhythmias and SCD.

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Ternushchak, Tetyana M., and Marianna I. Tovt-Korshynska. "RISK PREDICTION FOR ARRHYTHMIA IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE." Wiadomości Lekarskie 74, no. 10 (2021): 2605–9. http://dx.doi.org/10.36740/wlek202110214.

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The aim: To evaluate P-wave dispersion (PwD), as an independent predictor of atrial fibrillation, corrected QT interval dispersion (cQTD), the noninvasive marker of ventricular arrhythmia and sudden cardiac death, investigate the atrial electromechanical delay in patients with COPD and assess their relation with the severity of the disease. Materials and methods: We prospectively enrolled consecutive patients with newly diagnosed COPD (n = 53, age 41.2 ± 6.8 years), compared with an age-matched healthy control group (n = 51, age 40.9 ± 6.5 years). A standard 12-lead electrocardiogram of each patient was analyzed for PwD and сQTD. Atrial electromechanical delay was analyzed by echocardiographic tissue Doppler imaging. The difference between PAs-PAl, PAs-PAt, and PAl-PAt were defined as left intra-atrial, right intra-atrial, and interatrial electromechanical delays (EMD), respectively. Results: PwD was higher in COPD patients than in control subjects (39.47 ± 3.12 ms vs. 30.29 ± 3.17 ms, p < 0.05). In comparison between control group and COPD subgroups (mild, moderate and severe), there was a statistically significant difference among these free groups in terms of PwD. Subgroup analyses showed that this difference was mainly due to patients with severe COPD. Regarding cQTD, there was a statistically significant increase in COPD patients 57.92 ± 3.43 ms vs 41.03 ± 5.21 ms, p < 0.05 respectively. PAs, PAl and PAt durations, right intra-atrial and interatrial EMD were also significantly longer in COPD patients (p < 0.05). Furthermore, there were significant negative correlations between FEV1 and PwD (r = – 0.46, p < 0.05), right intra-atrial (r = – 0.39 ms, p < 0.05), interatrial EMD ( r = – 0.35 ms, p < 0.05) and cQTD (r = – 0.32, p < 0.05). Conclusions: Atrial conduction time, such as inter- and intra-atrial EMD intervals, PwD and cQTD were longer than in healthy controls and correlated with the severity of COPD. These parameters offer a non-invasive and cost-effective assessment method for detecting patients at high risk of arrhythmia. Nevertheless, further prospective investigations on this issue are required.

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Özer, Necla, Bünyamin Yavuz, Ilknur Can, Enver Atalar, Serdar Aksöyek, Kenan Övünç, Ferhan Özmen, and Sırrı Kes. "Doppler Tissue Evaluation of Intra-atrial and Interatrial Electromechanical Delay and Comparison with P-wave Dispersion in Patients with Mitral Stenosis." Journal of the American Society of Echocardiography 18, no. 9 (September 2005): 945–48. http://dx.doi.org/10.1016/j.echo.2005.01.015.

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Bessiere, F., A. Zorgani, L. Daunizeau, E. Cao, F. Vaillant, E. Abell, B. Quesson, S. Catheline, P. Chevalier, and C. Lafon. "High frame rate ultrasounds for electromechanical wave imaging to characterize and differentiate endocardial from epicardial activation of ventricular arrhythmia: A proof of concept study." Archives of Cardiovascular Diseases Supplements 11, no. 2 (April 2019): 259. http://dx.doi.org/10.1016/j.acvdsp.2019.02.164.

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Wang, Hongliang, Yunfei Lv, Chaojie Wang, Xiangjun Wang, Changde He, Chenyang Xue, and Shuang He. "Simulation Analysis and Performance Testing Investigation of Capacitive Micromachined Ultrasonic Transducer." International Journal of Pattern Recognition and Artificial Intelligence 32, no. 09 (May 27, 2018): 1858004. http://dx.doi.org/10.1142/s0218001418580041.

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In various applications of ultrasonic waves, the ultrasonic transducer is the key device of ultrasonic testing and ultrasonic imaging. Compared with the traditional piezoelectric transducer, the capacitive micromachined ultrasonic transducer (CMUT) has many striking advantages, such as low impedance, high bandwidth, easy integration and low cost, and it is expected to become a next generation of mainstream products. In this paper, a CMUT structure for underwater-imaging applications is designed, and the finite element model is established by using COMSOL software, then the modal analysis, harmonic response analysis, electromechanical coupling analysis and transient analysis are carried out. As a consequence, the key parameters of CMUT are obtained, namely resonance frequency, voltage collapse and electromechanical coupling coefficient. For the processed CMUT line array consisting of 16 elements, a test system is built and the emission performance, receiving performance, directivity, bandwidth and preliminary imaging of the designed transducer are tested and analyzed. The results show that the designed CMUT array can meet the requirements of underwater-imaging applications.

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Struckman, Heather, Amara Greer-Short, Stephen Baine, Louisa Mezache, Anna Phillips, Sandor Gyorke, Thomas Hund, and Rengasayee Veeraraghavan. "The Nanoscale Basis of Atrial Fibrillation: Functional Impact of Disrupting NaV1.5-rich Intercalated Disk Nanodomains." Microscopy and Microanalysis 26, S2 (July 30, 2020): 832. http://dx.doi.org/10.1017/s1431927620016001.

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Background:Atrial fibrillation (AF), which is characterized by chaotic patterns of electrical activation of the atria, affects over 4 million people in the US alone. We previously identified nanoscale structural abnormalities in the hearts of AF patients. Specifically, they displayed swelling of gap junction (GJ) –adjacent perinexi, specialized nanodomains rich in cardiac sodium channels (NaV1.5) and located within intercalated disks (IDs; sites of electromechanical contact between adjacent cells). However, the functional consequences of these nanoscale structural changes remain unclear.Objective:We assessed the structural and functional impacts of selectively disrupting different NaV1.5-rich ID nanodomains.Methods and Results:We utilized peptide mimetics of adhesion domains to selectively inhibit adhesion within different ID nanodomains: 1) Nadp1 (target: N-cadherin), 2) dadp1 (target: Desmoglein-2), and 3) βadp1 (target: sodium channel β1 subunit [SCN1b]). Each active peptide was compared against a corresponding inactive control peptide (Nadp1-c, dadp1-c, βadp1-scr). Sub-diffraction confocal imaging revealed ID enrichment of active peptides, but not inactive controls. Furthermore, each active peptide was preferentially localized in ID regions rich in its corresponding protein target. Peptide treatment (100 μM; 60 minutes) of ex vivo mouse hearts revealed profound widening of perinexi by βadp1 and of mechanical junctions by Nadp1. Dadp1 also induced widening of mechanical junctions albeit to a lower degree. STORM single molecule localization microscopy identified about 50&per; of ID-localized NaV1.5 within GJ-adjacent perinexi, while an additional ∼35&per; was located within N-cad-rich ID sites. Nadp1 and βadp1 induced redistribution of ID localized NaV1.5 away from perinexi and mechanical junctions respectively. Dadp1, again, had similar but milder effects compared to Nadp1. Western blot revealed the expression levels of NaV1.5, connexin 43 (Cx43), connexin 40 (Cx40), β1 in peptide treated hearts to be within 10&per; of levels in untreated controls. Optical mapping revealed atrial conduction slowing in hearts treated with Nadp1 (17cm/s, 70.83&per; of control) and βadp1 (13 cm/s, 54.17&per; of control), but not inactive control peptides (24 cm/s). Volume-conducted electrocardiograms (ECG) revealed P wave prolongation in active peptide treated hearts (Nadp1: 26.5ms, βadp1: 31ms), consistent with conduction slowing compared to the inactive control peptides (16ms). Importantly, burst pacing elicited atrial arrhythmias in all hearts treated with Nadp1 and βadp1. Arrhythmia burden (duration, number of arrhythmias) was highest with βadp1.Conclusions:These results suggest that disruption of NaV1.5-rich ID nanodomains impairs electrical impulse propagation and promotes arrhythmias in the atria. Furthermore, the magnitude of functional impacts are likely determined by the amount of sodium channels contained within the nanodomains disrupted.

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Brodal, Eivind, Frank Melandsø, and Svein Jacobsen. "Performance of an Ultrasonic Imaging System Based on a 45-MHz Linear PVDF Transducer Array: A Numerical Study." Advances in Acoustics and Vibration 2011 (May 31, 2011): 1–15. http://dx.doi.org/10.1155/2011/984596.

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New designs of high-resolution ultrasonic imaging systems that operate in the 30–100 MHz region, for example, those based on linear transducer systems, are currently being investigated for medical purposes. Acoustic waves with frequencies in this range can detect microscopic structures in human tissue but will typically only penetrate a few mm because of large attenuation. However, this is sufficient for a diagnostic ultrasound scan of human skin. The signal-to-noise ratio and the focusing properties of the scanner are critical factors in dermatology, which are determined by the transducer design. A linear pulsed PVDF transducer array with a center frequency around 45 MHz is studied by applying numerical simulations, based on the finite element method (FEM), of this electromechanical system. Tx-beamforming properties of linear arrays with one, three, five, and seven active elements are investigated at different depths. The image quality obtained from synthetic Rx-beamforming, using responses from five electrodes, is estimated from reconstructed images of 25–100 m thick objects. The axial and lateral resolutions of these images are found to be similar with the Tx-beamforming resolution parameters estimated from the time-derivative of the pressure beams.

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Forrest, Abigail S., Talia C. Joyce, Marissa L. Huebner, Ramon J. Ayon, Michael Wiwchar, John Joyce, Natalie Freitas, et al. "Increased TMEM16A-encoded calcium-activated chloride channel activity is associated with pulmonary hypertension." American Journal of Physiology-Cell Physiology 303, no. 12 (December 15, 2012): C1229—C1243. http://dx.doi.org/10.1152/ajpcell.00044.2012.

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Pulmonary artery smooth muscle cells (PASMCs) are more depolarized and display higher Ca2+ levels in pulmonary hypertension (PH). Whether the functional properties and expression of Ca2+-activated Cl− channels (ClCa), an important excitatory mechanism in PASMCs, are altered in PH is unknown. The potential role of ClCa channels in PH was investigated using the monocrotaline (MCT)-induced PH model in the rat. Three weeks postinjection with a single dose of MCT (50 mg/kg ip), the animals developed right ventricular hypertrophy (heart weight measurements) and changes in pulmonary arterial flow (pulse-waved Doppler imaging) that were consistent with increased pulmonary arterial pressure and PH. Whole cell patch experiments revealed an increase in niflumic acid (NFA)-sensitive Ca2+-activated Cl− current [ ICl(Ca)] density in PASMCs from large conduit and small intralobar pulmonary arteries of MCT-treated rats vs. aged-matched saline-injected controls. Quantitative RT-PCR and Western blot analysis revealed that the alterations in ICl(Ca) were accompanied by parallel changes in the expression of TMEM16A, a gene recently shown to encode for ClCa channels. The contraction to serotonin of conduit and intralobar pulmonary arteries from MCT-treated rats exhibited greater sensitivity to nifedipine (1 μM), an l-type Ca2+ channel blocker, and NFA (30 or 100 μM, with or without 10 μM indomethacin to inhibit cyclooxygenases) or T16AInh-A01 (10 μM), TMEM16A/ClCa channel inhibitors, than that of control animals. In conclusion, augmented ClCa/TMEM16A channel activity is a major contributor to the changes in electromechanical coupling of PA in this model of PH. TMEM16A-encoded channels may therefore represent a novel therapeutic target in this disease.

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Winter, R., A. Fazlinezhad, S. Martins Fernandes, M. Pellegrino, X. Iriart, S. Moustafa, D. Stolfo, et al. "Poster session 3The imaging examinationP646Simulator-based testing of skill in transthoracic echoP647Clinical and echocardiographic characteristics of isolated left ventricular non-compactionP648Appropriate use criteria of transthoracic echocardiography and its clinical impact in an aged populationAnatomy and physiology of the heart and great vesselsP649Prevalence and determinants of exercise oscillatory ventilation in the EUROEX trial populationAssessment of diameters, volumes and massP650Left atrial remodeling after percutaneous left atrial appendage closureP651Global atrial performance with tyrosine kinase inhibitors in metastatic renal cell carcinomaP652Early right ventricular response to cardiac resynchronization therapy: impact on clinical outcomesP653Parameters of speckle-tracking echocardiography and biomechanical values of a dilative ascending aortaAssessments of haemodynamicsP654Right atrial hemodynamics in infants and children: observations from 3-dimensional echocardiography derived right atrial volumesAssessment of systolic functionP655One-point carotid wave intensity predicts cardiac mortality in patients with congestive heart failure and reduced ejection fractionP656Persistence of cardiac remodeling in adolescents with previous fetal growth restrictionP6572D speckle tracking-derived left ventricle global longitudinal strain and left ventricular dysfunction stages: a useful discriminator in moderate-to-severe aortic regurgitationP658Global longitudinal strain and strain rate in type two diabetes patients with chronic heart failure: relevance to circulating osteoprotegerinP659Analysis of left ventricular function in patients before and after surgical and interventional mitral valve therapyP660Left ventricular end-diastolic volume is complementary with global longitudinal strain for the prediction of left ventricular ejection fraction in echocardiographic daily practiceP661Left ventricular assist device, right ventricle function, and selection bias: the light side of the moonP662Assessment of right ventricular function in patients with anterior ST elevation myocardial infarction; a 2-d speckle tracking studyP663Right ventricular systolic function assessment in sickle cell anaemia using echocardiographyAssessment of diastolic functionP664Prognostic value of transthoracic cardiopulmonary ultrasound in cardiac surgery intensive care unitP665Comparative efficacy of renin-angiotensin system modulators on prognosis, right heart and left atrial parameters in patients with chronic heart failure and preserved left ventricular systolic functionP666Left atrial volume index is the most significant diastolic functional parameter of hemodynamic burden as measured by NT-proBNP in acute myocardial infarctionP667Preventive echocardiographic screening. preliminary dataP668Assessment of the atrial electromechanical delay and the mechanical functions of the left atrium in patients with diabetes mellitus type IIschemic heart diseaseP669Coronary flow velocity reserve by echocardiography as a measure of microvascular function: feasibility, reproducibility and agreement with PET in overweight patients with coronary artery diseaseP670Influence of cardiovascular risk in the occurrence of events in patients with negative stress echocardiographyP671Prevalence of transmural myocardial infarction and viable myocardium in chronic total occlusion (CTO) patientsP672The impact of the interleukin 6 receptor antagonist tocilizumab on mircovascular dysfunction after non st elevation myocardial infarction assessed by coronary flow reserve from a randomized studyP673Impact of manual thrombus aspiration on left ventricular remodeling: the echocardiographic substudy of the randomized Physiologic Assessment of Thrombus Aspirtion in patients with ST-segment ElevatioP674Acute heart failure in STEMI patients treated with primary percutaneous coronary intervention is related to transmural circumferential myocardial strainP675Long-term prognostic value of infarct size as assessed by cardiac magnetic resonance imaging after a first st-segment elevation myocardial infarctionHeart valve DiseasesP676Prognostic value of LV global longitudinal strain in aortic stenosis with preserved LV ejection fractionP677Importance of longitudinal dyssynchrony in low flow low gradient severe aortic stenosis patients undergoing dobutamine stress echocardiography. a multicenter study (on behalf of the HAVEC group)P678Predictive value of left ventricular longitudinal strain by 2D Speckle Tracking echocardiography, in asymptomatic patients with severe aortic stenosis and preserved ejection fractionP679Clinical and echocardiographic characteristics of the flow-gradient patterns in patients with severe aortic stenosis and preserved left ventricular ejection fractionP6802D and 3D speckle tracking assessment of left ventricular function in severe aortic stenosis, a step further from biplane ejection fractionP681Functional evaluation in aortic stenosis: determinant of exercise capacityP682Left ventricular mechanics: novel tools to evaluate left ventricular function in patients with primary mitral regurgitationP683Plasma B-type natriuretic peptide level in patients with isolated rheumatic mitral stenosisP684Quantitative assessment of severity in aortic regurgitation and the influence of elastic proprieties of thoracic aortaP685Characterization of chronic aortic and mitral regurgitation using cardiovascular magnetic resonanceP686Functional mitral regurgitation: a warning sign of underlying left ventricular systolic dysfunction in heart failure with preserved ejection fraction.P687Secondary mitral valve tenting in primary degenerative prolapse quantified by three-dimensional echocardiography predicts regurgitation recurrence after mitral valve repairP688Advanced heart failure with reduced ejection fraction and severe mitral insufficiency compensate with a higher oxygen peripheral extraction to a reduced cardiac output vs oxygen uptake response to maxP689Predictors of acute procedural success after percutaneous mitraclip implantation in patients with moderate-to-severe or severe mitral regurgitation and reduced ejection fractionP690The value of transvalvular gradients obtained by transthoracic echocardiography in estimation of severe paravalvular leakage in patients with mitral prosthetic valvesP691Characteristics of infective endocarditis in a non tertiary hospitalP692Infective endocarditis: predictors of severity in a 3-year retrospective analysisP693New echocardiographic predictors of early recurrent mitral functional regurgitation after mitraclip implantationP694Transesophageal echocardiography can be reliably used for the allocation of patients with severe aortic stenosis for tras-catheter aortic valve implantationP695Annular sizing for transcatheter aortic valve selection. A comparison between computed tomography and 3D echocardiographyP696Association between aortic dilatation, mitral valve prolapse and atrial septal aneurysm: first descriptive study.CardiomyopathiesP698Cardiac resynchronization therapy by multipoint pacing improves the acute response of left ventricular mechanics and fluid dynamics: a three-dimensional and particle image velocimetry echo studyP699Long-term natural history of right ventricular function in dilated cardiomyopathy: innocent bystander or leading actor?P700Right to left ventricular interdependence at rest and during exercise assessed by the ratio between pulmonary systolic to diastolic time in heart failure reduced ejection fractionP701Exercise strain imaging demonstrates impaired right ventricular contractile reserve in patients with hypertrophic cardiomyopathyP702Prevalence of overt left ventricular dysfunction (burn-out phase) in a portuguese population of hypertrophic cardiomyopathy, a multicentre studyP703Systolic and diastolic myocardial mechanics in hypertrophic cardiomyopathy and their link to the extent of hypertrophy, replacement fibrosis and interstitial fibrosisP704Multimodality imaging and genotype-phenotype associations in a cohort of patients with hypertrophic cardiomyopathy studied by next generation sequencing and cardiac magnetic resonanceP705Sudden cardiac death risk assessment in apical hypertrophic cardiomyopathy: do we need to add MRI to the equation?P706Prognostic value of left ventricular ejection fraction, proBNP, exercise capacity, and NYHA functional class in patients with left ventricular non-compaction cardiomyopathyP707The anti-hypertrophic microRNAs miR-1, miR-133a and miR-26b and their relationship to left ventricular hypertrophy in patients with essential hypertensionP708Prevalence of left ventricular systolic dysfunction in a portuguese population of left ventricular non-compaction cardiomyopathy, a multicentre studyP709Assessment of systolic and diastolic features in light chain amyloidosis: an echocardiographic and cardiac magnetic resonance studyP710Morbid obesity-associated hypertension identifies bariatric surgery best responders: Clinical and echocardiographic follow up studyP711Echocardiographic markera for overhydration in patients under haemodialysisP712Gender aspects of right ventricular size and function in clinically stable heart transplant patientsP713Evidence of cardiac stem cells from the left ventricular apical tip in patients undergone LVAD implant: a comparative strain-ultrastructural studySystemic diseases and other conditionsP714Speckle tracking assessment of right ventricular function is superior for differentiation of pressure versus volume overloaded right ventricleP715Prognostic value of pulmonary arterial pressure: analysis in a large dataset of timely matched non-invasive and invasive assessmentsP716Effect of the glucagon-like peptide-1 analogue liraglutide on left ventricular diastolic and systolic function in patients with type 2 diabetes: a randomised, single-blinded, crossover pilot studyP717Tissue doppler evaluation of left ventricular functions, left atrial mechanical functions and atrial electromechanical delay in juvenile idiopathic arthritisP718Echocardiographic detection of subclinical left ventricular dysfunction in patients with rheumatoid arthritisP719Left ventricular strain values are unaffected by intense training: a longitudinal, speckle-tracking studyP720Diastolic left ventricular function in autosomal dominant polycystic kidney disease: a matched-cohort, speckle-tracking echocardiographic studyP721Relationship between adiponectin level and left ventricular mass and functionP722Left atrial function is impaired in patients with multiple sclerosisMasses, tumors and sources of embolismP723Paradoxical embolization to the brain in patients with acute pulmonary embolism and confirmed patent foramen ovale with bidirectional shunt, results of prospective monitoringP724Following the European Society of Cardiology proposed echocardiographic algorithm in elective patients with clinical suspicion of infective endocarditis: diagnostic yield and prognostic implicationsP725Metastatic cardiac18F-FDG uptake in patients with malignancy: comparison with echocardiographic findingsDiseases of the aortaP726Echocardiographic measurements of aortic pulse wave velocity correlate well with invasive methodP727Assessment of increase in aortic and carotid intimal medial thickness in adolescent type 1 diabetic patientsStress echocardiographyP728Determinants and prognostic significance of heart rate variability in renal transplant candidates undergoing dobutamine stress echocardiographyP729Pattern of cardiac output vs O2 uptake ratio during maximal exercise in heart failure with reduced ejection fraction: pathophysiological insightsP730Prognostic value and predictive factors of cardiac events in patients with normal exercise echocardiographyP731Right ventricular mechanics during exercise echocardiography: normal values, feasibility and reproducibility of conventional and new right ventricular function parametersP732The added value of exercise-echo in heart failure patients: assessing dynamic changes in extravascular lung waterP733Applicability of appropriate use criteria of exercise stress echocardiography in real-life practice: what have we improved with new documents?Transesophageal echocardiographyP7343D-TEE guidance in percutaneous mitral valve interventions correcting mitral regurgitationContrast echocardiographyP735Pulmonary transit time by contrast enhanced ultrasound as parameter for cardiac performance: a comparison with magnetic resonance imaging and NT-ProBNPReal-time three-dimensional TEEP736Optimal parameter selection for anisotropic diffusion denoising filters applied to aortic valve 4d echocardiographsP737Left ventricle systolic function in non-alcoholic cirrhotic candidates for liver transplantation: a three-dimensional speckle-tracking echocardiography studyTissue Doppler and speckle trackingP738Optimizing speckle tracking echocardiography strain measurements in infants: an in-vitro phantom studyP739Usefulness of vascular mechanics in aortic degenerative valve disease to estimate prognosis: a two dimensional speckle tracking studyP740Vascular mechanics in aortic degenerative valve disease: a two dimensional speckle-tracking echocardiography studyP741Statins and vascular load in aortic valve disease patients, a speckle tracking echocardiography studyP742Is Left Bundle Branch Block only an electrocardiographic abnormality? Study of LV function by 2D speckle tracking in patients with normal ejection fractionP743Dominant inheritance of global longitudinal strain in a population of healthy and hypertensive twinsP744Mechanical differences of left atria in paroxysmal atrial fibrillation: A speckle-tracking study.P745Different distribution of myocardial deformation between hypertrophic cardiomyopathy and aortic stenosisP746Left atrial mechanics in patients with chronic renal failure. Incremental value for atrial fibrillation predictionP747Subclinical myocardial dysfunction in cancer patients: is there a direct effect of tumour growth?P748The abnormal global longitudinal strain predicts significant circumflex artery disease in low risk acute coronary syndromeP7493D-Speckle tracking echocardiography for assessing ventricular funcion and infarct size in young patients after acute coronary syndromeP750Evaluation of left ventricular dyssynchrony by echocardiograhy in patients with type 2 diabetes mellitus without clinically evident cardiac diseaseP751Differences in myocardial function between peritoneal dialysis and hemodialysis patients: insights from speckle tracking echoP752Appraisal of left atrium changes in hypertensive heart disease: insights from a speckle tracking studyP753Left ventricular rotational behavior in hypertensive patients: Two dimensional speckle tracking imaging studyComputed Tomography & Nuclear CardiologyP754Effectiveness of adaptive statistical iterative reconstruction of 64-slice dual-energy ct pulmonary angiography in the patients with reduced iodine load: comparison with standard ct pulmonary angiograP755Clinical prediction model to inconclusive result assessed by coronary computed tomography angiography." European Heart Journal – Cardiovascular Imaging 16, suppl 2 (December 2015): S102—S129. http://dx.doi.org/10.1093/ehjci/jev277.

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Özsoy, Çağla, Ali Özbek, Michael Reiss, Xosé Luís Deán-Ben, and Daniel Razansky. "Ultrafast four-dimensional imaging of cardiac mechanical wave propagation with sparse optoacoustic sensing." Proceedings of the National Academy of Sciences 118, no. 45 (November 3, 2021). http://dx.doi.org/10.1073/pnas.2103979118.

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Abstract:

Significance Propagation of electromechanical waves in excitable heart muscles follows complex spatiotemporal patterns holding the key to understanding life-threatening arrhythmias. Despite recent progress, there is a lack of cardiac imaging methods capable of transmural visualization of fast electromechanical phenomena across the beating heart. Here we introduce a sparse optoacoustic sensing technique for ultrafast four-dimensional imaging of cardiac mechanical wave propagation in the entire beating murine heart with high contrast and sub-millisecond temporal resolution. We extract accurate dispersion and phase velocity maps of the cardiac waves and reveal vortex-like patterns associated with mechanical phase singularities that occur during arrhythmic events induced via ventricular stimulation. Our cardiac mapping approach is a bold step toward deciphering the complex mechanisms underlying cardiac arrhythmias.

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Jafaripour, I., Z. Aryanian, S. Hosseinzadeh, R. Pourkia, MM Ansari Ramandi, A. Kebria Shirzadian, S. Tirgar Tabari, and M. Pourkia. "Impaired atrial electromechanical coupling in lichen planus patients." European Heart Journal - Cardiovascular Imaging 22, Supplement_1 (January 1, 2021). http://dx.doi.org/10.1093/ehjci/jeaa356.109.

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Abstract Funding Acknowledgements Type of funding sources: None. Introduction Lichen planus (LP) which is a chronic inflammatory disease can cause impaired atrial electromechanical coupling, leading to increased risk of atrial fibrillation. Purpose The present study aimed to evaluate atrial electromechanical coupling in LP patients by using electrocardiography (ECG) and echocardiography. Methods Forty-six LP patients were investigated in this cross-sectional case-control study. The control group comprised healthy individuals selected in age and gender-matched manner. Echocardiography and ECG were done for all patients to show inter and intra-atrial electromechanical delays and P wave dispersion respectively. The electromechanical delays were calculated by using the difference between the delays from the onset of the P wave on ECG to the onset of A wave on tissue Doppler recordings of the different areas. Results The baseline characteristics of the case and control group were similar and did not differ significantly. The P wave dispersion was 45.63 ± 3.48 milliseconds in the LP group in comparison to 36.56 ± 2.87 milliseconds in the control group (p < 0.001). As shown in the table, the intra and inter-atrial electromechanical delays were also significantly prolonged in LP patients when compared to the control group (p < 0.001). There was no significant difference between the left and right ventricular systolic function and diastolic function of the two groups. Conclusion The results of the study indicate the presence of significant impaired atrial electromechanical coupling in patients with LP confirmed by both electrocardiographic and echocardiographic tools. Electromechanical delays Case N = 46 (mean ± SD) Control N = 46 (mean ± SD) P value Septal - PA (msec) 59.71 ± 13.24 44.39 ± 11.07 0.002 Lateral - PA (msec) 55.71 ± 13.26 48.89 ± 11.21 0.009 Tricuspid - PA (msec) 52.37 ± 13.12 43.28 ± 10.58 0.002 Inter-atrial delay (msec) (lateral PA−RV PA) 8.47 ± 1.62 6.37 ± 1.36 <0.001 Intra-atrial delay (msec) (LA) [lateral PA−septal PA] 4.80 ± 1.48 3.83 ± 0.82 <0.001 Intra-atrial delay (msec) (RA) [septal PA−RV PA] 3.91 ± 0.96 2.02 ± 0.71 <0.001 PA Delay from the onset of the P wave on ECG to the onset of A wave on tissue Doppler, N: number, SD: Standard Deviation, LA: Left Atrium, RA: Right Atrium, RV: Right Ventricle

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Bu, Gang, Daumantas Ciplys, Michael Shur, Remis Gaska, Qhalid Fareed, Romualdas Rimeika, Jinwei Yang, and Asif Khan. "Surface Acoustic Waves And Guided Optical Waves In AlGaN Films." MRS Proceedings 764 (2003). http://dx.doi.org/10.1557/proc-764-c6.10.

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Abstract:

AbstractAlxGa1-xN layers grown by MOCVD on sapphire substrates have been tested using the surface acoustic wave and guided optical wave techniques. Samples with molar fraction of Al up to 0.36 have been investigated. The parameters S11 of single surface acoustic wave transducers and S12 of two-port devices have been measured with the network analyzer. The values of the surface acoustic wave velocity and electromechanical coupling coefficient for the layer-substrate structure have been extracted and calculated using material parameters available from literature. The attenuation of guided optical waves along the propagation track in AlxGa1-xN layers has been measured using the CCD imaging technique. The attenuation dependence on the mode order and layer thickness has been studied. Our results show that the properties of AlxGa1-xN that determine surface acoustic wave and guided optical wave propagation are similar to the properties of GaN films within a relatively wide range of x up to x =0.36.