Prolonged recovery time in the left precordial leads reflects increased left ventricular mass in the hypertensive patients.
Hypertensive left ventricular hypertrophy (LVH) is considered to be a risk for arrhythmogenicity, but the quantification of the changes in T-wave morphology, as the reflection of repolarization abnormality, has not been fully established. The purpose of this study was to quantify the T-wave changes in the hypertensive patients and to investigate the relationship with the increased left ventricular mass. Standard 12-lead electrocardiogram and echocardiogram were recorded in 90 hypertensive patients. Activation time (AT), activation recovery interval (ARI), and recovery time (RT) were measured in the precordial lead and QT interval in the 12 leads. To compare the left precordial T-wave changes among patients, measurements of ARI and RT in the right precordial negative T wave were excluded. Each parameter excluding AT was corrected with Bazett formula, and then the dispersion was calculated. Left ventricular mass index was determined echocardiographically to select non-LVH group (n=31) and LVH group (n=59). In both groups, AT, ARI, and RT in the left precordial leads were larger compared with those in the right precordial leads. Dispersion of AT was not different between the 2 groups. However, the dispersion of ARI and RT in LVH group was significantly greater than that in non-LVH group. There were correlations between left ventricular mass index and the dispersion of RT (r=0.66, P<.001), ARI (r=0.61, P<.001), and 12-lead QT (r=0.42, P<.001). In patients with LVH, significant prolongation of RT in the left precordial leads was observed, suggesting that this RT change resulted from the nonuniformity of epicardial action potential duration.
Hara
Hideyuki
H
Department of Internal Medicine/Cardiology, School of Medicine, Kitasato University, Kanagawa 228-8555, Japan. hideyuki@med.kitasato-u.ac.jp
Niwano
Shinichi
S
Ikeda
Noriaki
N
Izumi
Tohru
T
D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000175:diagnosis*; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020127:Recovery of Function; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013997:Time Factors