Cardiovascular function in breast cancer patients receiving radiotherapy

Radiotherapy is also increasingly being used in the treatment and management of breast cancer and lung cancer; these conditions often require irradiation of the chest area and structures close to the heart. Acute and long-term alterations in biological function have been reported in many cases of radiation exposure, which may be for medicinal, industrial or cosmetic purposes and sometimes accidental and incidental exposure as in nuclear warfare. Cardiovascular function was studied in some female patients with breast cancer undergoing radiation therapy. Blood pressure was recorded by the sphygmomanometric/ auscultatory method and electrocardiogram was recorded with a standard ECG machine. Heart rate was obtained from the radial pulse or computed from the ECG. Healthy female volunteers served as controls. There was no significant difference in blood pressure between the cancer patients undergoing radiotherapy and control subjects, body temperatures were also similar (36.7 +/- 0.13 cf 36.6 +/- 0.077 degrees C). However heart rate increased significantly (83.6 +/- 3.0 cf 72.44 +/- 1.9 beats/min), (p < 0.01). Analysis of the ECG showed that PR interval was shorter in radiotherapy patients (p < 0.05). The R-R interval was also shorter than in the controls. The amplitude of the QRS complex was reduced in cancer patients undergoing radiotherapy (p < 0.05). However there was no change in the T-wave amplitude in the two groups. Acute radiotherapy to the chest area did not significantly alter blood pressure and electrocardiogram but increased heart rate and reduced the amplitude of QRS complex in breast cancer patients.