Value of leads V-7-V-9 in diagnosing posterior wall acute myocardial infarction and other causes of tall R waves in V-1-V-2

Diagnosing transmural posterior wall acute myocardial infarction from the 12-lead electrocardiogram (ECG) is often difficult,(1) but in the thrombolytic era it is important. Recording 3 additional electrocardiographic leads (V-7, V-8, V-9) appears to be a simple and accurate means of making the diagnosis, and this communication describes the method and its results.