title: Use of the signal-averaged QRS duration for diagnosing left ventricular hypertrophy in hypertensive patients.
abstract: We analysed the diagnostic performance of the signal-averaged QRS duration for the detection of left ventricular hypertrophy in 100 consecutive outpatients (62 men and 38 women; mean age, 49.8 +/- 11.8 years) with essential hypertension and compared the results with some of the currently employed electrocardiographic criteria. Forty-eight healthy subjects (24 men and 24 women; mean age, 46.4 +/- 12.1) with normal physical, electrocardiographic and echocardiographic findings served as a control group to derive normal reference values for signal-averaged QRS duration. Twenty-six (26%) hypertensives (22 men and 4 women) had left ventricular hypertrophy echocardiographically defined as a left ventricular mass > or = 261 g in men and > or = 172 g in women or left ventricular mass index > or = 125 g/m2 in men and > or = 112 g/m2 in women. The signal-averaged QRS duration was different in patients with than in those without left ventricular hypertrophy (102.1 +/- 10.8 vs. 95.8 +/- 8.4 ms; P < 0.01). Also, in the group with left ventricular hypertrophy QRS duration was longer, although not significantly different, in men than in women (103.5 +/- 10.7 vs. 94.2 +/- 8.8 ms; P n.s.). The correlation between the signal-averaged QRS duration and left ventricular mass was weak but statistically significant in men (r = 0.34; P < 0.05) in women (r = 0.30; P < 0.05) and in men and women together (r = 0.42; P < 0.01). Partition values of filtered QRS duration > or = 114 ms in men and > or = 107 ms in women were used to diagnose left ventricular hypertrophy as these values were above the upper limits in our control men and women when 95% confidence intervals were calculated. These criteria were insensitive (12%) but highly specific (99%) for left ventricular hypertrophy. The use of a single threshold value of filtered QRS duration > or = 111 ms in both sexes combined improved sensitivity modestly (15%) while maintaining a good specificity (95%). Also, we tested the following standard electrocardiographic criteria: the Sokolow-Lyon index, the Romhilt-Estes point score > or = 4 points and > or = 5 points, the Cornell voltage criteria, the sum of QRS voltages in all 12 leads > 175 mm, and the QRS duration > 90 ms. Sensitivities ranged from 4% to 58% and specificities from 74% to 99%.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: Department of Internal Medicine, School of Cardiovascular Diseases, University of Rome Tor Vergata, Italy.
authors.forename: P V
authors.initials: PV
authors.lastname: Fragola
authors.forename: D
authors.initials: D
authors.lastname: De Nardo
authors.forename: L
authors.initials: L
authors.lastname: Calò
authors.forename: D
authors.initials: D
authors.lastname: Cannata
mesh_terms: D004452:Echocardiography; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D012737:Sex Factors; D012815:Signal Processing, Computer-Assisted