Relation of QT interval and QT dispersion to echocardiographic left ventricular hypertrophy and geometric pattern in hypertensive patients. The LIFE study.

Objective In hypertensive patients, left ventricular hypertrophy (LVH) pred icts increased mortality, in part due to an increased incidence of sudden d eath. Repolarization-related arrhythmogenesis may be an important mechanism of sudden death in hypertensive patients with LVH. Increased QT interval a nd QT dispersion are electrocardiographic (ECG) measures of ventricular rep olarization, and also risk markers for ventricular tachyarrhythmias. We ass essed the relation of QT intervals and QT dispersion to echocardiographical ly determined left ventricular (LV) mass and geometry in a large population of hypertensive patients with ECG evidence of LVH. Methods QT intervals and QT dispersion were determined from baseline 12-lea d ECGs in 577 (57% male; mean age 65 +/- 7 years) participants in the LIFE study. LV mass index (LVMI) and geometric pattern were determined by echoca rdiography and QT interval duration and QT dispersion were assessed in rela tion to gender-specific LVMI quartiles. Results In both genders, increasing LVMI was associated with longer rate-ad justed QT intervals. QT dispersion measures showed a weaker association wit h LVMI quartiles. Both concentric and eccentric LVH were associated with in creased QT interval duration and QT dispersion. These relations remained si gnificant after controlling for relevant clinical variables. Conclusions In hypertensive patients with ECG evidence of LVH, increased LV MI and LVH are associated with a prolonged QT interval and increased QT dis persion. These findings suggest that an increased vulnerability to repolari zation-related ventricular arrhythmias might in part explain the increased risk of sudden death in hypertensive patients with increased LV mass. (C) 2 001 Lippincott Williams & Wilkins.