Nondominant right coronary artery disease. A source for right ventricular infarction, anginal pain, and a positive exercise electrocardiogram.

A patient is described who presented with isolated episodes of typical angina pectoris. Subsequent exercise electrocardiogram was positive, and cardiac catheterization revealed a 90 percent lesion of a nondominant right coronary artery supplying only the right ventricular (RV) myocardium. The left coronary artery was normal. Stress gated equilibrium radionuclide angiograms (RNA) revealed a normal left ventricular exercise response and a markedly abnormal RV response (RV ejection fraction decreased from 31 percent at rest to 27 percent at peak stress). Nondominant right coronary artery lesions can be a source of angina pectoris, RV infarction, and a positive ECG response to exercise. Stress RNA can be useful in evaluating the functional significance of these lesions.