The influence of ventricular hypertrophy upon the cardiogram of anterior cardiac infarction.

The presence of an S wave, preceded by an r wave in lead V5 (rS pattern) has been interpreted as indicating extreme clockwise rotation of the electrical position of the heart around its vertical axis (Goldberger, 1947, 1949). A deep S wave in V5 occurs in right ventricular hypertrophy (Myers et al., 1948), while an R/S ratio less than unity in V5 (rS pattern) when occurring in conjunction with a qR pattern in VR, was considered by Pagnoni and Goodwin (1952) to be diagnostic of right ventricular hypertrophy in adults, in the absence of cardiac infarction, ventricular aneurysm, or right bundle-branch block. The rS pattern in V5 has also been shown to occur in combined ventricular hypertrophy (Goldberger, 1949; Pagnoni and Goodwin, 1952). A prominent S wave (not exceeding the R wave in amplitude) can occur in normal persons (Myers et al., 1947). In Leatham's (1950) series of 100 normal subjects, the rS pattern occurred only in two, and R was equal to S in one other. Although cardiograms have been published showing rS patterns in V5 in cases with autopsy proof of anterior infarction, (Myers et al., 1949; Levy and Hyman, 1950) little has been written about this pattern in cardiac infarction. The unexpected finding of anterior cardiac infarction at autopsy, in patients whose cardiograms showed no unusual features other than an rS complex in V5, prompted the present investigation into the genesis of this pattern, with special reference to right ventricular hypertrophy, combined ventricular hypertrophy, and cardiac infarction.