Cardiac complications of radiation therapy

To present an overview of cardiac complications arising from radiation therapy.

Medline the (February 2004) and Embase (1974 to February 2004) searches of the medical literature relating to the cardiac complications of radiotherapy were conducted.

Radiation damage may affect the pericardium, myocardium or coronary vasculature, and consists of fibrotic or small vessel damage. Cardiac complications are a particular problem with radiation treatments to the mediastinum and breast, especially when greater than 65% of the heart is irradiated. Most of the literature relates to the treatment of Hodgkin's disease, as patients with this disease tend to be young and live long enough to manifest late cardiac complications. Pericarditis, angina, myocardial infarction and arrhythmias are the most frequent causes of morbidity, with myocardial infarction being the most common fatal complication. The incidence of ischaemic heart disease does not increase rapidly until 10 years from treatment.

Much of the evidence relates to the use of outdated radiation therapy equipment and techniques. Today's patients almost certainly have a lower risk of cardiac complications. Cardiac complications are probably under-reported, as they occur long after cured patients have been discharged from follow-up.