DETERMINATION OF LEFT-VENTRICULAR MASS IN SYSTEMIC HYPERTENSION - COMPARISON OF STANDARD AND SIGNAL-AVERAGED ELECTROCARDIOGRAPHY

Objective-To investigate the quantitative relationship, if any, betwee n signal averaged electrocardiographic variables and echocardiographic ally determined left ventricular mass in hypertensive subjects. Design -Cohort analytic prospective study. Setting-University hospital. Subje cts-50 hypertensive subjects selected consecutively fr om inpatients. Patients older than 75 years, with underlying cardiac disease, with in conclusive echocardiograms with bundle branch block, or in atrial fibr illation were excluded. Interventions-Antihypertensive therapy involvi ng 41 patients was continued. Main outcome measures-Left ventricular m ass calculated in accordance with the standards of the Penn convention . Thirteen criteria derived from combinations of signal averaged elect rocardiographic X, Y, and Z Frank orthogonal leads, including voltage criteria, duration, and time-voltage integrals of the QRS complex. Fou r widely used standard electrocardiographic criteria for detection of left ventricular hypertrophy. Results-There was no difference in the v alues for any of the electrocardiographic variables between patients w ith (n = 29) and without left ventricular hypertrophy (n = 21). The ti me-voltage integral of QRS in the horizontal plane was the best signal averaged variable related to left ventricular mass (r = 0.33, P = 0.0 19); however, the correlation with Rodstein voltage was stronger (r = 0.46, P = 0.0009). A positive correlation was also found between left ventricular indexed mass and Rodstein voltage (r = 0.43, P = 0.0019). Stepwise regression analysis revealed Rodstein voltage as the only pre dictor of indexed mass (P = 0.0019), and Rodstein voltage (P = 0.0022) and body weight (P = 0.011) as the only independent correlates of lef t ventricular mass. Conclusions-The relation between electrocardiograp hic variables and left ventricular mass or indexed mass is of limited value; signal averaged orthogonal leads do not improve this assessment compared with standard electrocardiographic leads.