Electrocardiographic diagnosis of left ventricular hypertrophy in hypertension

The prevalence and correlates of echocardiographic left ventricular hypertrophy among employed patients with uncomplicated hypertension

To determine the prevalence and correlates of echocardiographic left ventricular hypertrophy among subjects in a general population, we studied 621 employed subjects. Patients with uncomplicated essential hypertension in a worksite-based treatment program included 145 with borderline hypertension and 316 with sustained hypertension by World Health Organization criteria. Normotensive subjects were randomly selected from members of the same unions. M-mode echocardiographic left ventricular dimensions were used to calculate left ventricular mass and other indexes of left ventricular anatomy. The specificity of 13 echocardiographic criteria of left ventricular hypertrophy was determined in normotensive individuals, and the prevalence of left ventricular hypertrophy by each criterion was assessed in patients with borderline or sustained essential hypertension. The results suggest that the most suitable reference standard for detection of left ventricular hypertrophy in a heterogeneous urban population utilizes sex-specific cutoff values for left ventricular mass index of 110 g/m2 or greater for women and 134 g/m2 or greater for men. With 97% specificity, the prevalence of left ventricular hypertrophy by these criteria is approximately 12% among patients with borderline hypertension and 20% among patients with relatively mild, uncomplicated sustained essential hypertension. Wall thickness measurements performed slightly less well. At similar levels of blood pressure, black patients were more likely than white patients to exhibit concentric left ventricular hypertrophy, especially among borderline hypertensive patients. Left ventricular hypertrophy occurred in patients with sustained hypertension who also exhibited increased cardiac output, strongly associated with low plasma renin activity.

Serial electrocardiographic changes in treated hypertensive patients with reference to voltage criteria, mean QRS vectors, and the QRS-T angle

Serial changes in voltage, QRS vectors, and QRS-T angles were studied in 44 patients who had shown improvement in their electrocardiograms during treatment for hypertension. Changes were observed in a number of electrocardiographic voltage criteria often used in the study of left ventricular hypertrophy. This is consistent with a change in the magnitude of the mean QRS vector and its reflection on a variety of ECG leads even if pretreatment records were normal. Improvement also occurred in the mean T vectors and the QRS-T angle. It is proposed that serial changes in the ECG might be of greater value than pretreatment abnormalities in diagnosing the disorder of cardiac structure or function that occurs in hypertension.

Effect of Body Build on the QRS Voltage of the Electrocardiogram in Normal Men

Various sets of QRS voltages that are used in the diagnosis of left ventricular hypertrophy were determined from the electrocardiograms of 300 normal men judged to be free from cardiopulmonary disease, and these were correlated to body build expressed in terms of ponderal index. A correlation was found for all voltages studied and a highly significant correlation was found for the criteria "R I + S III " "greatest R + greatest S in the precordial leads" and "greatest R + S in a single precordial lead." Age or activity did not appear to be specific factors in the population studied. Graphs were constructed for the latter three sets of voltages defining upper limits of normal for various values of the ponderal index. By using these sets of voltage criteria in conjunction with this index, one would hopefully improve both accuracy and specificity in the electrocardiographic diagnosis of early left ventricular hypertrophy.