RIGHT-VENTRICULAR LATE FILLING TERMINATION TIME AND ITS RELATION TO INTERSTITIAL COLLAGEN CONTENT IN EARLY TRANSPLANTED HEART - A COLOR M-MODE DOPPLER DIGITAL ANALYSIS

Background: Histologic changes in cardiac allografts resulting from fi brosis or acute rejection can modify ventricular diastolic function an d ventricular inflow characteristics. These abnormalities may be detec ted by color M-mode Doppler echocardiography which has been shown to b e sensitive in assessing ventricular diastolic function. Methods: Twel ve cardiac allograft recipients were prospectively studied with serial color M-mode and single-gated Doppler echocardiography, as well as wi th endomyocardial biopsy, with a follow-up of approximately 10 weeks. The myocardial interstitial collagen content as evaluated by videodens itometry was compared with right and left ventricular late filling ter mination times measured in the absence of a severe episode of rejectio n. Results: A positive and significant correlation was found between t he collagen content and the corresponding right ventricular late filli ng termination time (r = 0.89, p < 0.0001), but no correlation was fou nd with the left ventricular late filling termination time. Moreover, variations in collagen content and variations in right ventricular lat e filling termination time were also highly correlated (r = 0.91, p < 0.0001). In allograft recipients who had episodes of rejection of grad e 3A or greater, both right and left ventricular late filling terminat ion times were significantly increased during rejection. Conclusions: Measurements of right ventricular late filling termination time by col or hi-mode Doppler echocardiography performed in the absence of acute rejection can be used to monitor the evolution of interstitial collage n content in cardiac allografts. The early detection of abnormally pro longed late filling termination time could be followed by endomyocardi al biopsy to confirm the histologic changes.