Bibliographies thématiques / Atrioventricular coupling

Littérature scientifique sur le sujet « Atrioventricular coupling »

Auteur : Grafiati
Publié le 20 juillet 2024

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Articles de revues sur le sujet "Atrioventricular coupling"

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Sjöberg, Pia, Ellen Ostenfeld, Erik Hedström, Håkan Arheden, Ronny Gustafsson, Shahab Nozohoor et Marcus Carlsson. « Changes in left and right ventricular longitudinal function after pulmonary valve replacement in patients with Tetralogy of Fallot ». American Journal of Physiology-Heart and Circulatory Physiology 318, no 2 (1 février 2020) : H345—H353. http://dx.doi.org/10.1152/ajpheart.00417.2019.

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Timing and indication for pulmonary valve replacement (PVR) in patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) are uncertain. To improve understanding of pumping mechanics, we investigated atrioventricular coupling before and after surgical PVR. Cardiovascular magnetic resonance was performed in patients ( n = 12) with rToF and PR > 35% before and after PVR and in healthy controls ( n = 15). Atrioventricular plane displacement (AVPD), global longitudinal peak systolic strain (GLS), atrial and ventricular volumes, and caval blood flows were analyzed. Right ventricular (RV) AVPD and RV free wall GLS were lower in patients before PVR compared with controls ( P < 0.0001; P < 0.01) and decreased after PVR ( P < 0.0001 for both). Left ventricular AVPD was lower in patients before PVR compared with controls ( P < 0.05) and decreased after PVR ( P < 0.01). Left ventricular GLS did not differ between patients and controls ( P > 0.05). Right atrial reservoir volume and RV stroke volume generated by AVPD correlated in controls ( r = 0.93; P < 0.0001) and patients before PVR ( r = 0.88; P < 0.001) but not after PVR. In conclusion, there is a clear atrioventricular coupling in patients before PVR that is lost after PVR, possibly because of loss of pericardial integrity. Impaired atrioventricular coupling complicates assessment of ventricular function after surgery using measurements of longitudinal function. Changes in atrioventricular coupling seen in patients with rToF may be energetically unfavorable, and long-term effects of surgery on atrioventricular coupling is therefore of interest. Also, AVPD and GLS cannot be used interchangeably to assess longitudinal function in rToF. NEW & NOTEWORTHY There is a clear atrioventricular coupling in patients with Tetralogy of Fallot (ToF) and pulmonary regurgitation before surgical pulmonary valve replacement (PVR) that is lost after operation, possibly because of loss of pericardial integrity. The impaired atrioventricular coupling complicates assessment of ventricular function after surgery when using measurements of longitudinal function. Left ventricular atrioventricular plane displacement (AVPD) found differences between patients and controls and changes after PVR that longitudinal strain could not detect. This indicates that AVPD and strain cannot be used interchangeably to assess longitudinal function in repaired ToF.
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Vîjîiac, Aura, Alina Ioana Scărlătescu, Ioana Gabriela Petre, Cristian Vîjîiac et Radu Gabriel Vătășescu. « Three-Dimensional Combined Atrioventricular Coupling Index—A Novel Prognostic Marker in Dilated Cardiomyopathy ». Biomedicines 12, no 2 (28 janvier 2024) : 302. http://dx.doi.org/10.3390/biomedicines12020302.

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Atrioventricular coupling has recently emerged as an outcome predictor. Our aim was to assess, through three-dimensional (3D) echocardiography, the role of the left atrioventricular coupling index (LACI), right atrioventricular coupling index (RACI) and a novel combined atrioventricular coupling index (CACI) in a cohort of patients with dilated cardiomyopathy (DCM). One hundred twenty-one consecutive patients with DCM underwent comprehensive 3D echocardiographic acquisitions. LACI was defined as the ratio between left atrial and left ventricular 3D end-diastolic volumes. RACI was defined as the ratio between right atrial and right ventricular 3D end-diastolic volumes. CACI was defined as the sum of LACI and RACI. Patients were prospectively followed for death, heart transplant, nonfatal cardiac arrest and hospitalization for heart failure. Fifty-five patients reached the endpoint. All three coupling indices were significantly more impaired in patients with events, with CACI showing the highest area under the curve (AUC = 0.66, p = 0.003). All three indices were independent outcome predictors when tested in multivariable Cox regression (HR = 2.62, p = 0.01 for LACI; HR = 2.58, p = 0.004 for RACI; HR = 2.37, p = 0.01 for CACI), but only CACI showed an incremental prognostic power over traditional risk factors such as age, left ventricular strain, right ventricular strain and mitral regurgitation severity (likelihood ratio χ2 test = 28.2, p = 0.03). CACI assessed through 3D echocardiography, reflecting both left and right atrioventricular coupling, is an independent predictor of adverse events in DCM, yielding an incremental prognostic power over traditional risk factors.
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Sengupta, Partho P., et Jagat Narula. « À LA Mode Atrioventricular Mechanical Coupling ». JACC : Cardiovascular Imaging 7, no 1 (janvier 2014) : 109–11. http://dx.doi.org/10.1016/j.jcmg.2013.12.001.

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Gourdie, R. G., N. J. Severs, C. R. Green, S. Rothery, P. Germroth et R. P. Thompson. « The spatial distribution and relative abundance of gap-junctional connexin40 and connexin43 correlate to functional properties of components of the cardiac atrioventricular conduction system ». Journal of Cell Science 105, no 4 (1 août 1993) : 985–91. http://dx.doi.org/10.1242/jcs.105.4.985.

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Electrical coupling between heart muscle cells is mediated by specialised regions of sarcolemmal interaction termed gap junctions. In previous work, we have demonstrated that connexin42, a recently identified gap-junctional protein, is present in the specialised conduction tissues of the avian heart. In the present study, the spatial distribution of the mammalian homologue of this protein, connexin40, was examined using immunofluorescence, confocal scanning laser microscopy and quantitative digital image analysis in order to determine whether a parallel distribution occurs in rat. Connexin40 was detected by immunofluorescence in all main components of the atrioventricular conduction system including the atrioventricular node, atrioventricular bundle, and Purkinje fibres. Quantitation revealed that levels of connexin40 immunofluorescence increased along the axis of atrioventricular conduction, rising over 10-fold between atrioventricular node and atrioventricular bundle and a further 10-fold between atrioventricular bundle and Purkinje fibres. Connexin40 and connexin43, the principal gap-junctional protein of the mammalian heart, were co-localised within atrioventricular nodal tissues and Purkinje fibres. By applying a novel photobleach/double-labelling protocol, it was demonstrated that connexin40 and connexin43 are co-localised in precisely the same Purkinje fibre myocytes. A model, integrating data on the spatial distribution and relative abundance of connexin40 and connexin43 in the heart, proposes how myocyte-type-specific patterns of connexin isform expression account for the electrical continuity of cardiac atrioventricular conduction.
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Spitzer, K. W., N. Sato, H. Tanaka, L. Firek, M. Zaniboni et W. R. Giles. « Electrotonic modulation of electrical activity in rabbit atrioventricular node myocytes ». American Journal of Physiology-Heart and Circulatory Physiology 273, no 2 (1 août 1997) : H767—H776. http://dx.doi.org/10.1152/ajpheart.1997.273.2.h767.

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Electrotonic effects of electrically coupling atrioventricular (AV) nodal cells to each other and to real and passive models of atrial and ventricular cells were studied using a technique that does not require functional gap junctions. Membrane potential was measured in each cell using suction pipettes. Mutual entrainment of two spontaneously firing AV nodal cells was achieved with a junctional resistance (Rj) of 500 M omega, which corresponds to only 39 junctional channels, assuming a single-channel conductance of 50 pS. Coupling of AV nodal and atrial cells at Rj of 50 M omega caused hyperpolarization of the nodal cell, decreasing its action potential duration and either slowing or blocking diastolic depolarization in the AV node myocyte. Opposite changes occurred in the atrial action potential. When AV nodal and ventricular cells were coupled at Rj of 50 M omega, nodal diastolic potential was markedly hyperpolarized and diastolic depolarization was completely blocked with little change in ventricular diastolic potential. However, coupling did elicit marked changes in the action potential duration of both cells, with prolongation in the nodal cell and shortening in the ventricular cell. Nodal maximum upstroke velocity was increased by both atrial and ventricular coupling, as expected from the hyperpolarization that occurred. With an Rj of 50 M omega, spontaneous firing was blocked in all single AV nodal pacemaker cells during coupling to a real or passive model of an atrial or ventricular cell. These results demonstrate that action potential formation and waveform in a single AV nodal cell is significantly affected by electrical coupling to other myocytes.
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Terlizzi, Vito Di, Roberta Barone, Nicola Di Nunno, Gianmarco Alcidi, Natale Daniele Brunetti et Massimo Iacoviello. « The Atrioventricular Coupling in Heart Failure : Pathophysiological and Therapeutic Aspects ». Reviews in Cardiovascular Medicine 25, no 5 (14 mai 2024) : 169. http://dx.doi.org/10.31083/j.rcm2505169.

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Pham, Caroline, Svitlana Podliesna, Arie Verkerk, Rianne Wolswinkel, Noelia Muñoz-Martín, Marieke Veldkamp, Leander Beekman et al. « TNNI3K delays atrioventricular conduction and reduces connexin-45 gap junctional coupling ». Journal of Molecular and Cellular Cardiology 173 (décembre 2022) : 83–84. http://dx.doi.org/10.1016/j.yjmcc.2022.08.167.

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Hernández Burgos, Paula M., et Angel López-Candales. « Changes in Mitral Annular Ascent with Worsening Echocardiographic Parameters of Left Ventricular Diastolic Function ». Scientifica 2016 (2016) : 1–4. http://dx.doi.org/10.1155/2016/6303815.

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Background. While the mitral annular plane systolic excursion (MAPSE) has been suggested as a surrogate measurement of left ventricular ejection fraction, less is known about the relative value of mitral annular ascent (MAa).Methods. Our database was queried for complete transthoracic echocardiograms performed for any clinical indication. Baseline echocardiographic measurements were compared to determine any correlation between MAa and traditional Echo-Doppler echocardiographic measures to characterize left ventricular diastolic dysfunction (LVDD).Results. Patients with normal LV diastolic function were younger (41±13years) than patients with LVDD (stage 1:61±13years; stage 2:57±14years; and stage 3:66±17years;p=0.156). LV ejection fraction decreased in patients with stage 2 LVDD (63±17%) and was further reduced in patients with stage 3 LVDD (28±21;p=0.003).Discussion. While a vigorous MAa excursion was seen in patients with stage 1 LVDD, MAa significantly decreased in stage 2 and stage 3 LVDD patients. Our results highlight the importance of atrioventricular coupling, as MAa motion seems to reflect changes in left atrial pressure. Additional studies are now required to better examine atrioventricular interactions and electromechanical coupling that might improve our assessment of LV diastolic function.
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Mazgalev, Todor, Kent Mowrey, Igor Efimov, Gerard J. Fahy, David Van Wagoner, Yuanna Cheng et Patrick J. Tchou. « Mechanism of atrioventricular nodal facilitation in rabbit heart : role of proximal AV node ». American Journal of Physiology-Heart and Circulatory Physiology 273, no 4 (1 octobre 1997) : H1658—H1668. http://dx.doi.org/10.1152/ajpheart.1997.273.4.h1658.

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The phenomenon of atrioventricular (AV) nodal “facilitation,” described in traditional “black box”-functional studies, implies enhanced AV nodal dromotropic function. We investigated the role of atrial prematurities in the modulation of the nodal cellular responses in the mechanism of AV nodal facilitation. Atrial and His (H) bundle electrograms and microelectrode recordings from proximal AV nodal cells were analyzed in 15 superfused rabbit AV node preparations. The pacing protocol consisted of 30 basic beats (S1; coupling interval S1-S1= 300 ms) followed by a facilitating prematurity (S2; coupling intervals S1-S2of 300, 200, 150, and 130 ms) followed by the test beat (S3; coupling interval S2-S3scanned in 5-ms steps). Conduction curves (S2-H2vs. S1-S2, S3-H3vs. S2-S3, and S3-H3vs. H2-S3) were constructed. Facilitation (i.e., shortening of S3-H3when S1-S2was shortened) was demonstrated in all preparations using the H2-S3( P < 0.001) but not the S2-S3format. Microelectrode recordings revealed a causal relationship between the improved proximal AV nodal cellular responses in facilitation and the prolonged S2-S3interval. There was no evidence for enhanced nodal dromotropic function directly resulting from the introduction of the facilitating beats. Thus facilitation is based on inherent cycle-length-dependent properties of the AV node during application of a complex pacing protocol and primarily reflects the uncontrolled modulation of the proximal cellular response.
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Masè, Michela, Leon Glass, Marcello Disertori et Flavia Ravelli. « The AV synchrogram : A novel approach to quantify atrioventricular coupling during atrial arrhythmias ». Biomedical Signal Processing and Control 8, no 6 (novembre 2013) : 1008–16. http://dx.doi.org/10.1016/j.bspc.2013.01.004.

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Thèses sur le sujet "Atrioventricular coupling"

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Gueda, Moussa Moussa. « Biomarqueurs quantitatifs de la déformation myocardique multi-chambres et multidirectionnelle en imagerie IRM dynamique ». Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS104.pdf.

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La déformation du myocarde quantifiée en imagerie échocardiographique ou en imagerie par résonnance magnétique (IRM) dynamique par traitement d'images conventionnel (suivi de textures), est un marqueur puissant de l'atteinte myocardique, tant il est modifié précocement au cours de la maladie comparé aux marqueurs globaux communément utilisés en routine clinique. Malgré ses performances, son utilisation systématique en routine reste entravée par la complexité et le temps d'analyse nécessaires à l'initialisation manuelle des bords du myocarde.De plus, les logiciels cliniques sont le plus souvent spécifiques au ventricule gauche du cœur, omettant les autres cavités qui sont aussi les cibles de maladies mais ayant une géométrie nettement plus complexe. Dans ce contexte, les objectifs principaux de cette thèse sont : 1) d'évaluer la déformation myocardique par suivi de texture en IRM dans toutes les cavités cardiaques tout en étudiant les effets de l'âge sur les indices estimés, 2) de tirer avantage de ces contours de suivi de texture afin de proposer de nouveaux biomarqueurs quantitatifs de couplage mécano-fonctionnels entres les oreillettes et les ventricules dans le vieillissement en bonne santé, 3) d'évaluer l'effet centre et constructeur sur ces mesures et sur les mesures de strain dérivées par suivi de texture en IRM
Myocardial strain quantified from echocardiography or from cine magnetic resonance imaging (MRI) using conventional image processing (speckle or feature tracking), is a powerful markerof myocardial damage, as it is modified earlier in the course of the disease as compared to global markers commonly used in clinical routine. Despite such performances, its systematic use in routine remains hampered by the complexity and the time-consuming nature of the manual initialization of the myocardial borders. Besides, clinical software is most often specific to the left ventricle, omitting the other chambers which are also targets of diseases but havinga much more complex geometry. In such a context, the main objectives of this thesis are: 1) to evaluate myocardial deformation through MRI feature tracking in all cardiac chambers while studying the effects of age on the estimated indices, 2) to take advantage of feature tracking derived contours in order to design new quantitative biomarkers of mechano-functional coupling between the atria and the ventricles in healthy aging, 3) to evaluate effect of data from different centers and manufacturers on these measurements and on strain measurements derived by feature tracking from cine MRI
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Wright, Stephen. « Left Atrial Phasic Function during Exercise : The Role of Atrioventricular Coupling ». Thesis, 2013. http://hdl.handle.net/1807/43337.

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Left ventricular (LV) filling increases during exercise, but left atrial (LA) phasic function and its contribution to LV filling is poorly understood. Sixteen endurance-trained middle-aged males were studied at rest and during light (LE) and moderate (ME) intensity cycle-ergometry. Atrioventricular-plane displacement (AVPD) increased from rest to LE (from 14±2 mm to 18±2 mm, p<0.01), but did not increase further at ME. LA reservoir volume increased from rest to LE (from 32±8 mL to 40±10 mL, p<0.01). LA passive contribution increased at LE (from 21±5 mL to 27±8 mL, p<0.01), while LA active contribution increased from rest only at ME (from 12±5 mL to 23±9 mL, p<0.01). AVPD, and thus the longitudinal shortening of LV systole, contributes to LA filling primarily during LE, but is a limited mechanism beyond LE. These data suggest that LV filling appears to shift to a reliance on conduit function to increase LV filling at ME.
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