SERIAL ECHOCARDIOGRAPHIC EVALUATION OF CARDIAC GRAFT-REJECTION AFTER INFANT HEART-TRANSPLANTATION

The effects of cardiac graft rejection on infant myocardial function assessed by echocardiography are largely unknown. To quantitate the myocardial response to rejection, serial echocardiographic studies were prospectively performed on 20 infants (less than 1 year of age at transplantation). Two-dimensional guided-M-mode tracings were digitized and quantified with a computer-assisted format. Rejection was diagnosed by clinical criteria, and 85% were graded as mild, that is without cardiac signs or symptoms. Echocardiographic analysis was blinded to rejection status, with studies available 4.2 +/- 2.9 days before rejection, on the day of rejection diagnosis, and 2.9 +/- 1.5 days after rejection treatment. Left ventricular mass increased acutely from 109% of predicted normal to 129% with rejection and decreased to 110% with therapy (p < 0.01). Left ventricular volume also tended to fall with rejection and increase with therapy. The left ventricular volume/mass ratio fell from 0.29 +/- 0.10 to 0.25 +/- 0.13 and increased to 0.37 +/- 0.15 (p < 0.05) with treatment. Systolic function was depressed by rejection as reflected in the posterior wall thickening fraction and velocity of wall thickening. Diastolic dysfunction was reflected in a decreased velocity of posterior wall thinning (-9.7 +/- 3.9 to -7.7 +/- 2.7 and recovery to -10.8 +/- 3.8 (1/second, p < 0.05) and depressed average velocity of cavity enlargement (41.2 +/- 9.6 to 36.4 +/- 8.9 and recovery to 40.7 +/- 8.6 mm/sec, p < 0.05). The utility of these echocardiographic measurements to predict rejection has not been prospectively compared with the endomyocardial biopsy. We conclude that quantitative echocardiography can detect a consistent pattern of infant left ventricular dysfunction associated with the clinical diagnosis of mild rejection.