Effects of Radiations on the Heart

Publisher Website
Google Scholar
Abstract
A clinical and electrocardiographic study of the effects of radiations on the heart is prefaced by a critical review of the clinical and experimental literature. The inherent radiosensitivity of the heart is low. In contrast, electrocardiographic changes occur with moderate dosage in radiotherapy. A study was made of the conditions under which clinical syndromes, referable to the heart and attributed to radiotherapy, occurred. The most important are extra-cardiac mediastinal disturbances leading sometimes to pericarditis. Such "mediastino-pericardial reactions" are rare, but are most often encountered during irradiation of a radiosensitive tumour (such as a thymoma) which invades the pericardium. In carcinomatous pericarditis, usually from metastatic breast carcinoma, the chronic changes are attributable to the stromal reaction (which may in one instance have been increased by radiotherapy). A study was made of 25 consecutive female patients receiving 250 kV X-ray therapy for breast carcinoma. The examinations included 12 lead electrocardio-graphy at intervals from the start of radiotherapy up to 2 years after. Clinical and fluoroscopic examinations showed no changes in the heart in any case. Four patients (16%) developed pathological changes in the E. C. G.; these occurred mainly in patients having previous evidence of ischaemic heart disease, and were symptomless, apparently trivial and usually transient. The possible pathogenesis of these changes is discussed. While such studies have provided evidence of a cardiac effect of irradiation it is important that they should not, on present information, be used to limit essential radiotherapy.