Early cardiac changes related to radiation therapy.
To investigate the incidence and severity of possible radiation-induced cardiac changes, 21 women without heart disease were investigated serially by echocardiography and by measuring systolic time intervals before and up to 6 months after postoperative radiation therapy because of breast cancer. Radiation was associated with a decrease in fractional systolic shortening of the left ventricular (LV) minor-axis diameter, from 0.35 +/- 0.05 to 0.32 +/- 0.06 (p less than 0.005), and in the systolic blood pressure/end-systolic diameter ratio, from 4.4 +/- 1.2 to 3.9 +/- 0.9 mm Hg/mm (p less than 0.005). The mitral E point-septal separation increased, from 2.8 +/- 1.5 to 4.2 +/- 2.5 mm (p less than 0.005). The preejection period/LV ejection time ratio of systolic time intervals increased, but only the decrease within 6 months after therapy was significant (p less than 0.005). All these changes reflect slight transient depression of LV function, which became normalized within 6 months after therapy. Up to 6 months after therapy, a slight pericardial effusion was found in 33% of the patients. Hence, conventional radiation therapy appeared to cause an acute transient and usually symptomless decrease in LV function, and later, slight pericardial effusion in one-third of the patients.
D001794:Blood Pressure; D001943:Breast Neoplasms / Q000532:radiotherapy; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000528:radiation effects*; D006801:Humans; D010490:Pericardial Effusion / Q000209:etiology; D011832:Radiation Injuries / Q000209:etiology; D013902:Radiography, Thoracic; D011878:Radiotherapy / Q000009:adverse effects*; D013599:Systole