ACUTE CARDIAC EFFECTS OF MEDIASTINAL IRRADIATION - ASSESSMENT BY RADIONUCLIDE ANGIOGRAPHY

Mediastinal irradiation is considered as a long term cardiac risk factor, although no myocardial dysfunction can usually be documented during long term follow-up of the patients having undergone this treatment. We prospectively studied on 124 patients the early effects of irradiation on the myocardium using radionuclide angiography Left ventricular ejection fraction was measured at three different times: before starting the irradiation, 15 days after and more than 2 months after the end of the treatment. The patients were divided into four groups according to the type of irradiation received: M group of 53 patients (mediasteinal irradiation), L group of 33 patients (left mammary chain irradiation), R group of 25 patients (right mammary chain irradiation), C group for 13 control patients (irradiation field did not include the heart). Sixty-nine of these patients were treated by chemotherapy, including adriamycin in 48 of them. For all patients for whom the myocardium was included into the field of irradiation (M, L, and R) there is a significant fall of the Left ventricular ejection fraction 15 days after the end of treatment, with recovery after 2 months. This fall is not seen in controls. Patients who received adriamycin follow the same evolution, and there is no significant difference in the basal LVEF value nor in the magnitude of the fall.