Myocardial performance index in pediatric patients after cardiac transplantation

Background Myocardial performance index (MPI) has been shown to be a reliable indicator of ventricular performance. This study determined MPI values in pediatric patients after cardiac transplantation without endomyocardial rejection. Methods MPI was determined in 41 pediatric patients after cardiac transplantation, without evidence of microscopic rejection, and in 31 pediatric control subjects. Results MPI in the transplantation group (0.41 ± 0.12) was higher than in the control group (0.31 ± 0.09; P = .0003). Isovolumic relaxation time and isovolumic relaxation time/ejection time were higher in the transplant group (55 ± 20 milliseconds and 0.22 ± 0.07, respectively) compared with the control group (41 ± 10 milliseconds and 0.16 ± 0.06, respectively; P = .0002). Isovolumic contraction time and isovolumic contraction time/ejection time were similar in the transplant group (48 ± 23 milliseconds and 0.19 ± 0.09, respectively) and control group (43 ± 21 milliseconds and 0.16 ± 0.08, respectively; P = not significant). Conclusions Pediatric patients after cardiac transplantation without endomyocardial rejection have a higher MPI compared with a normative pediatric control population. The difference appears to be related to abnormal diastolic function.