COMPARISON OF CARDIAC-FUNCTION TESTS AFTER ANTHRACYCLINE THERAPY IN CHILDHOOD - IMPLICATIONS FOR SCREENING

Background. Numerous methods for evaluating cardiac function after car diotoxic therapy have been suggested. A practical algorithm for screen ing a large patient population is needed. Methods. Seventy-three patie nts (median age, 15.3 years [range, 9-29 years) who received anthracyc lines (median dose, 300 mg/m2 [range, 50-750 mg/m2) for a childhood ma lignancy underwent a battery of commonly used tests of cardiac functio n: (1) echocardiographic shortening fraction (ESF); (2) resting and ex ercise radionuclide scan (multiple gaited acquisition [MUGA]); (3) ele ctrocardiogram (ECG); (4) 24-hour Holter monitor, and (5) questionnair e concerning exercise tolerance. Results. Patients with an abnormal re sting ejection fraction on MUGA were more likely to have an abnormal E SF (P = 0.023), prolongation of the QT(c) interval (P = 0.014), and co mplaints of ''difficulty'' with exercise (P = 0.04). An abnormal resul ts for a resting study was not predictive of an abnormal MUGA exercise response. There was no association between the presence of significan t dysrhythmia on Holter monitor and any resting test. An algorithm was developed using a normal ESF and QT(c) interval, and a negative histo ry of exercise intolerance to identify patients who need not undergo a MUGA. With the use of such an algorithm, 29 of the 73 patients would not have undergone the MUGA, only 2 of whom had an abnormal resting ej ection fraction. Conclusion. Patients at risk for cardiac damage after cancer therapy who have normal ESF and QT(c) interval results and no history of exercise intolerance are unlikely to have abnormal MUGA res ults. Significant dysrhythmia may be present in the absence of other a bnormalities.