Kahn and colleagues [1] described two patients with isolated right ventricular infarction due to a lesion in a nondominant right coronary artery who were treated with angioplasty. Both presented with normal 12-lead electrocardiograms, although the second developed atrial fibrillation.

We previously described a similar patient who presented with atrial fibrillation and isolated ST-segment elevation in lead V1 with inferolateral ST depression [2]. Isolated right ventricular infarction was confirmed by creatine kinase elevation, echocardiography, and right-heart catheterization. Post-infarction angina led to cardiac catheterization, which showed a codominant circulation with an anomalous right coronary artery arising from the left coronary cusp. Coronary angioplasty was done successfully on an 85% proximal stenosis of the right coronary artery, and the sinoatrial nodal artery appeared to originate distal to the lesion.

We agree that isolated right ventricular infarction may be an under-recognized entity because patients may have normal or unusual electrocardiographic findings. Atrial fibrillation has been described previously in patients with isolated right ventricular infarction [3], as might be expected from the usual origin of the sinus nodal artery from the right coronary artery. The combination of symptoms compatible with infarction, new-onset atrial fibrillation, and a normal 12-lead electrocardiogram or isolated ST elevation in lead VI would suggest isolated right ventricular infarction. Echocardiography and right-sided electrocardiographic leads may aid in diagnosis, as may right-heart catheterization in patients with hemodynamic compromise. The increased availability of angioplasty will undoubtedly lead to such treatment if the condition is recognized.