Electrocardiographic alterations in leads V1 to V3 in the diagnosis of right and left ventricular infarction.

As Q wave and ST segment elevation in leads V1 to V3 may be due either to right ventricular infarction (RVI) or to anterior left ventricular infarction (ALVI), 72 autopsy patients with acute myocardial infarction who had had conventional 12-lead ECG records were studied to determine the accuracy of these ECG criteria, both for the diagnosis of RVI (29 patients, group A) and of ALVI (43 patients, group B). The accuracy of three ECG criteria (Q wave, ST segment elevation greater than or equal to 0.05 mV, and ST segment elevation greater than or equal to 0.1 mV) in diagnosing group A and group B patients was determined in each precordial lead (V1, V2, and V3) and the three criteria were found to be significantly more accurate in diagnosing group B than group A patients. In conclusion, although Q wave and ST segment elevation in leads V1, V2, and V3 may be present in some cases of RVI, their accuracy is too low to be considered useful diagnostic criteria in these patients.