Effects of bone marrow transplantation on myocardial function in children

Of 41 pediatric patients currently alive after total body irradiation (TBI) and bone marrow transplantation (BMT), 30 (allogeneic 20, autologous 10) participated in the study. Pre-transplant therapy included high-dose cyclophosphamide (CY) and TBI (n = 12), high-dose CY alone (n = 4), high-dose Ara C and TBI (n = 5), cisplatinum, high-dose melphalan, VP-16 and TBI (n = 9). Acute cardiotoxicity was suggested by a > 15% decrease in the QRS voltage sum of the limb leads in all patients. Late cardiotoxicity was evaluated 0.5-10 years (median 5 years) post-transplant by ECG, chest radiograph, radionuclide cineangiography (RNCA) and echocardiography (ECHO). Six patients had a persistent decrease in the QRS amplitudes. They were all asymptomatic but had abnormal systolic function at the time of the study. BMT patients differed from their controls in the mean values of both the systolic and diastolic indices of myocardial function shown by RNCA and ECHO. Treatment was associated with decreased myocardial contractility. Isovolumic relaxation time and deceleration time were longer in BMT patients than in controls. Myocardial damage seemed to be worst after CY while high-dose Ara C was tolerated best. We conclude that both acute and late cardiotoxicity may occur after BMT, calling for long-term cardiac follow-up.