Effects of Recipient Atrial Contraction on Mitral Valve Motion in Orthotopic Cardiac Transplantation Filippos Triposkiadis, MD, Garrie J. Haas, MD, Elizabeth Sparks, RN, P. David Myerowitz, MD, Harisios Boudoulas, MD, and Randall C. Starling, MD R ecipient atrial remnants are electrically isolated and contract independently from donor atria and ventri- cles in orthotopic cardiac transplantation.L* Although the resulting variations in the timing of recipient atria1 contraction affect atrioventricular diastolic flow veloci- ties3-7 and ventricular diastolic pressure,* their impact on diastolic mitral valve motion has not been evaluated. Experimental8*g and clinical1o studieshave demonstrated that the mitral valve moves around a semiopenequilib- rium position in responseto changesin the transmitral pressure gradient and diastolic flow produced by left atria1or left ventricular contraction. It was hypothesized that mitral valve motion would be influenced by the tim- ing of recipient with respect to donor atria1contraction in orthotopic cardiac transplantation. The present study was undertaken to test this hypothesis. Five heart transplant patients (1 woman and 4 men, aged 46 f 8 years) with clearly identifiable recipient atria1 contractions on the surface electrocardiogram were studied 26 + 24 months (range 10 to 66) afier or- thotopic cardiac transplantation. All patients were treated with the standard immunosuppressive regimen of azathioprine, prednisone and cyclosporine A. The sys- tolic and diastolic blood pressures were 138 f 11 and 102 Z!Z 5 mm Hg, respectively. Three patients were in New York Heart Association functional class I and 2 were in class II. Patients with mitral regurgitation more than I+ as- sessed with Doppler echocardiography, atria1 fibrilla- tion and histologic evidence of grade IB or greater acute rejection” were excluded before entry into the study. M-mode and 2-dimensional echocardiograms were obtained with a Hewlett-Packard 77730 A imaging sys- tem equipped with a 3.0 MHz transducer. M-mode mea- surements of left ventricular diameters, septal and pos- terior wall thicknesses and left ventricular mass were obtained as previously described.t2J3 Echocardiographic recordings were made at 50 mmls. Recipient atria1 contractions were classified as (1) systolic tf they occurred between the onset of the QRS complex in the electrocardiogram and the point of mitral valve opening in the M-mode echocardiogram; (2) early diastolic if they occurred after mitral valve opening in the M-mode echocardiogram and before the electrocar- diographic P wave corresponding to donor atria1 con- traction; and (3) late diastolic if they occurred after the onset of the donor P wave and before onset of the QRS complex in the electrocardiogram. Donor atria1 contrac- tions were recognized by their occurrence before ven- tricular contractions with a constant P-QRS interval. From the Divisions of Cardiology and Cardiothoracic Surgery, Ohio State University, 647 Means Hall, 1654 Upham Drive, Columbus, Ohio 43210. Manuscript received May 4, 1993; revised manuscript received and accepted September 29, 1993. Mitral valve motion was assessed with 2-dimen- sional-guided M-mode echocardiography directed at the point of maximal anterior and posterior mitral valve leaflet excursion. The following points were identified at the anterior mitral valve leaflet echogram and were la- beled using conventional terminology as previously de- scribedI (Figure I ): (1) mitral valve opening: D point; (2) peak of early diastolic opening motion of anterior mitral valve leaflet: E point; (3) nadir of early diastolic opening motion of anterior mitral valve leaflet: F point; (4) peak of late diastolic opening motion of anterior mi- tral valve leaflet: A point; and (5) mitral valve closure: C point. In every cardiac cycle the following measurements were obtainedfiom the M-mode echogram of the mitral valve (Figure 1): The D, E, F, A and C points in the an- terior mitral valve echogram were timed with respect to the onset of the Q wave of the preceding QRS complex on the electrocardiogram. Amplitude measurements (made in millimeters) were (I) early diastolic mitral valve leaflet separation: dis- tance between the anterior and posterior mitral valve leaflets at the E point; (2) middle diastolic mitral valve leaflet separation: distance between the anterior and posterior mitral valve leaflets at the F point; and (3) late diastolic mitral valve leaflet separation: distance be- tween the anterior and posterior mitral valve leaflets at the A point. ECG I L 0 > TIME (msec) FIGURE 1. Gchematic representation of M-mode mitral valve echocardlogram. Time meawrements of mitral valve motion consisted of time intervals between onset of Q wave of the preceding QRG complex of the electrc- cardiogram and D, E, F, A and C points. Amplitude mee wrements of mitral valve motion consisted qf early (e), middle (f) and late diastolic (a) mitral valve leaflet sep aration. A = peak of late diastolic opening motion of the anterior mitral valve leaflet; C = mitral valve clo sure; D = mitral valve opening; E and F q peak and nadir of early diastolic opening motion of the anterior mitral valve leaflet. BRIEF REPORTS 1003