Left ventricular diastolic dysfunction induced by cyclophosphamide in blood stem cell transplantation

Cardiac complications are major limiting factors regarding the success of high-dose chemotherapy supported by blood stem cell transplantation (BSCT). The cardiotoxicity of cyclophosphamide remains obscure relative to that of anthracyclines. The aim of this study was to estimate noninvasively the cardiotoxicity of cyclophosphamide administered during the pretransplant conditioning of BSCT for patients with various hematological diseases. A total of 27 consecutive patients were divided into two groups depending on the conditioning regimen, ie, group A (n=15) which received cyclophosphamide (median dose of 120 mg/kg; range 100 to 200 mg/kg) and group B (n=12) which did not. Ultrasound cardiograms (UCG) and signal-averaged electrocardiograms (SAECG) were recorded in the two groups both preceding and following the BSCT. There were no statistical intergroup or intragroup differences in left ventricular (LV) dimensions or contractile function. Significant (P<0.01) posttransplant increases in interventricular septal wall thickness and Ap/Ep ratio were noted in group A. Moreover, the filtered QRS duration as estimated by SAECG was prolonged (P<0.05) whereas the summated LV voltage (S(V1)+R(V5)) was reduced in the posttransplant period only in group A. These results suggest that early cyclophosphamide cardiotoxicity was characterized by LV diastolic rather than systolic dysfunction. These findings may contribute to acute hemodynamic deterioration observed after cyclophosphamide-containing conditioning chemotherapy.