Atriogenic Diastolic Reflux
46 Years Later
A 59-year-old man was admitted for shortness of breath due to complete atrioventricular block. A transthoracic echocardiogram was performed to assess left ventricular ejection fraction before pacemaker implantation. Color Doppler recordings in the apical views revealed 2 small and central diastolic transmitral and transtricuspid reverse flows (Figure, A and online-only Data Supplement Movie I), concurrent with a mild aortic regurgitation (Figure, B and online-only Data Supplement Movie II). These reverse diastolic flows started after a nonconducted P wave and ended after the next P wave as demonstrated by color M-mode and pulsed-wave–Doppler recordings of both transmitral (Figure, D and F) and transtricuspid flows (Figure, C and E).
Atrioventricular (AV) diastolic regurgitation was first described as atriogenic diastolic reflux in patients with AV block by Rutishauser et al1 in 1966 with the use of thermodilution during cardiac catheterization. This study helped to understand the mechanisms of retrograde AV flow during diastole. When atrial contraction is not followed by synchronized ventricular contraction, the AV pressure gradient reverses during atrial relaxation, resulting in AV diastolic regurgitation in the presence of an incompletely closed AV valve. Effective ventricular contraction is indeed mandatory for complete AV closure. AV diastolic regurgitations are nowadays more easily recognized by echocardiography but they remain a puzzling finding.
Beside AV block of any degree, AV diastolic regurgitations can also occur in acute aortic regurgitation and severe heart failure in which high left ventricular filling pressures and a poorly compliant left ventricle are the etiopathogenic factors. Because of a low diastolic ventriculoatrial pressure gradient, AV diastolic regurgitations are generally mild and do not usually have therapeutic implications.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.112.154617/-/DC1.
- © 2013 American Heart Association, Inc.