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Mitral-Aortic Flow Reversal in Cardiac Resynchronization Therapy: Coupling With Ejection and Impact of Variations in Atrioventricular Delay.
- Source :
-
Circulation. Arrhythmia and electrophysiology [Circ Arrhythm Electrophysiol] 2017 May; Vol. 10 (5), pp. e004927. - Publication Year :
- 2017
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Abstract
- Background: Flow entering the left ventricle is reversed toward the outflow tract through rotating reversal flow around the mitral valve. This was thought to facilitate early ejection, but had not been proved to date. We hypothesized that perfect coupling between reversal and ejection flow would occur at optimal atrioventricular delay (AVD), contributing to its hemodynamic superiority, and evaluated its applicability for AVD optimization.<br />Methods and Results: Forty consecutive patients with cardiac resynchronization therapy underwent intracardiac flow analysis and AVD optimization. Reversal and ejection flow curves were studied. The presence and duration of reversal-ejection discontinuity were assessed for all programmed AVD. Reproducibility of each optimization method was evaluated through interobserver variability. Discontinuity between reversal and ejection flow was observed in all patients with longer than optimal AVD, increasing linearly with excess duration in AVD (linear R <superscript>2</superscript> =0.976, P <0.001). Longer discontinuities implied progressive decreases in pre-ejection flow velocity in the left ventricular outflow tract, with consequent loss of flow momentum. The equation optimal AVD=programmed AVD-[1.2(discontinuity duration)]+4 accurately predicted optimal AVD. Short AVD systematically compromised reversal flow because of premature ejection. Agreement over optimal AVD was superior when assessed by flow reversal method (intraclass correlation coefficient =0.931; P <0.001) over both iterative and aortic velocity-time integral methods.<br />Conclusions: Perfect coupling between mitral-aortic flow reversal and ejection flow in the left ventricle occurs at optimal AVD. As a result, full blood momentum in the outflow tract is used to facilitate early ejection. This can be measured and provides a new method for AVD optimization.<br /> (© 2017 American Heart Association, Inc.)
- Subjects :
- Aged
Aged, 80 and over
Aorta diagnostic imaging
Atrioventricular Node diagnostic imaging
Cardiomyopathies diagnosis
Cardiomyopathies physiopathology
Echocardiography, Doppler, Color
Echocardiography, Doppler, Pulsed
Female
Humans
Male
Middle Aged
Mitral Valve diagnostic imaging
Myocardial Perfusion Imaging methods
Prospective Studies
Regional Blood Flow
Spain
Time Factors
Treatment Outcome
Aorta physiopathology
Atrioventricular Node physiopathology
Cardiac Resynchronization Therapy methods
Cardiomyopathies therapy
Mitral Valve physiopathology
Stroke Volume
Ventricular Function, Left
Subjects
Details
- Language :
- English
- ISSN :
- 1941-3084
- Volume :
- 10
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Circulation. Arrhythmia and electrophysiology
- Publication Type :
- Academic Journal
- Accession number :
- 28500176
- Full Text :
- https://doi.org/10.1161/CIRCEP.116.004927