Can the index of myocardial performance be used to detect acute cellular rejection after heart transplantation?
The index of myocardial performance (IMP), combining systolic and diastolic function, was measured in 50 orthotopic heart transplant recipients to determine if it could be used to detect acute rejection. It was calculated as the sum of the isovolumic contraction time (IVCT) and isovolumic relaxation time (IVRT) divided by the ejection time. Comparison of intrarecipient changes in Doppler intervals between rejection and nonrejection states demonstrated an increase in IVCT and decrease in IVRT during rejection with no significant change in the IMP. Rejection is likely to be best detected by assessing these parameters independently rather than by measuring the IMP.