TIME-VOLTAGE QRS AREA OF THE 12-LEAD ELECTROCARDIOGRAM - DETECTION OFLEFT-VENTRICULAR HYPERTROPHY

Identification of left ventricular hypertrophy (LVH) using 12-lead ECG criteria based primarily on QRS amplitudes has been limited by poor s ensitivity at acceptable levels of specificity. Because the product of QRS voltage and duration, as an approximation of the time-voltage are a of the QRS complex, can improve accuracy of the 12-lead ECG for LVH, we examined the diagnostic value of true time-voltage area measuremen ts of QRS complexes from the standard 12-lead EGG. Standard 12-lead EC Gs and echocardiograms were obtained in 175 control subjects without L VH and in 74 patients with regurgitant valvular heart disease and LVH defined by echocardiographic criteria (indexed LV mass >110 g/m(2) in women and >125 g/m(2) in men), Standard voltage criteria, voltage-dura tion products (voltage multiplied by QRS duration), and true time-volt age areas of the QRS were calculated for Sokolow-Lyon criteria (SV1+RV 5/6) and the 12-lead sum of voltage criteria. Test sensitivities were compared using gender-specific partitions with matched specificity of 98% in the 175 subjects without LVH. Measurement of the time-voltage a rea significantly improved sensitivity for both criteria, The 76% sens itivity of the 12-lead sum area and 65% sensitivity of Sokolow-Lyon ar ea were significantly greater than the 54% sensitivity of the approxim ation of QRS area provided by each voltage-duration product (P<.001 an d P=.021) and than the 46% and 43% sensitivities of the respective sim ple voltage criteria (each P<.001), Comparison of receiver operating c haracteristic curves confirmed the superior overall performance of tim e-voltage area criteria compared with both voltage-duration products a nd simple voltage criteria. These results suggest that use of time-vol tage areas can dramatically improve identification of LVH by 12-lead E GG. Further study of this approach is needed to identify optimal crite ria for LVH based on the time-voltage area measurements from the 12-le ad ECG.