[Non-Q-wave-electrocardiograms. Signs of earlier myocardial infarction]

An increasing number of elderly people and diabetes patients with myocardial infarction go unrecognized because of painless ischemia and regression of major Q-waves over time. An increased awareness of diagnostic electrocardiogram (ECG) abnormalities other than Q-waves should allow physicians to optimize patient management. Particularly emphasized is the R-peak delay in V6, i.e. the R-peak in V6 being later than the S-peak in V2, as a sign of masked anterior myocardial infarction and ECG findings if infarcts are masked by left ventricular hemiblocks and left bundle branch block (LBBB). In left anterior hemiblocks dramatically decreased R-waves in leads II, III and AVF in conjunction with disappearance of Q-waves in leads I and aVL help to identify posterodiaphragmatic infarction. The left posterior hemiblock is itself a potent indicator of underlying posterodiaphragmatic infarction not recognized by Q-waves. In LBBB Cabrera's sign, RSR' morphology in the left-sided or inferior leads, inverse R-progression from V1 to V3 and primary repolarization abnormalities overlying the secondary T-wave changes are specific indicators of myocardial infarction. QRS-prolongation greater than 150 ms independently identifies ventricular function impairment in chronic coronary heart disease.