Pathophysiology and ECG patterns of isolated right ventricular infarction with nondominant right coronary artery.

The prevalence of isolated right ventricular infarction is 0.4-2.4\% in autopsy series and may occur by at least three different mechanisms, of which occlusion of a nondominant right coronary artery is reviewed here. Although rare, as oxygen demand/supply of the right is lower than that of the left ventricle, due to the smaller muscular mass, and it has a good prognosis, sudden death and cardiac rupture have been reported. Differential diagnosis with anterior infarction is needed. ECG may help but specific criteria should be adopted: dome-like and decreasing ST segment elevation from V1 to V3 leads; rapid ST segment normalization and no Q wave evolution from V1 to V3 leads, either accompanied or not by modest ST segment elevation in DIII (but not aVF) evolving in no Q wave; ST segment elevation in right-sided leads which should be explored; absence of ST segment depression in aVL; absent concomitant ST segment elevation in all inferior leads (DII, DIII, aVF). Applying these criteria may prevent erroneous management of right ventricular infarction if it is confused with left ventricular infarction. Right ventricular function evaluation should always be performed by echocardiography. Magnetic resonance imaging should be useful. An illustrative case and an ECG flow-chart are presented