Significance of the Initial R Wave in Lead aV R of the Electrocardiogram in the Diagnosis of Myocardial Infarction

Abstract

Distribution, means, and standard deviations of the initial R wave in lead aV _R of the electrocardiogram are investigated in 1,563 healthy U.S.A., Canadian, and Japanese men, ages 18 to 60 years, and on 448 healthy U.S.A., Canadian, and Japanese women, ages 17 to 51 years, and in samples of cardiac pathology. Findings in the normal group included an initial R wave in about 50% of the group, no significant effect of age, sex, or race on the mean initial R-wave amplitude in lead aV _R or its distribution, or on the upper 98% normal limit of the initial R wave, a decrease of the mean R amplitude in aV _R with clockwise rotation of the transitional zone, and a highly significant correlation of R amplitude in aV _R to that of R in V ₁ , Q ₃ , and Q in aV _F , but too low for reliable prediction. Right ventricular hypertrophy, anterior wall myocardial infarction, and hypertensive heart disease have no effect on the amplitude or prevalence of the initial R in aV _R . Posterior and anterior plus posterior wall infarction significantly increased amplitude and incidence of the initial R in aV _R .