Left ventricular wall stresses and wall stress-mass-heart rate products in hypertensive patients with electrocardiographic left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint reduction in hypertension.
Academic Article
Overview
abstract
OBJECTIVE: Left ventricular (LV) hypertrophy on echocardiogram (ECG) strongly predicts coronary heart disease events, but the mechanisms linking increased LV mass to ischemic vascular events is uncertain. DESIGN: Variables related to myocardial oxygen demand were compared among normotensive adults and patients with mild and more severe hypertension, and among groups of moderately hypertensive patients with target organ damage in relation to gender, LV geometry and LV systolic function. SETTING: The Losartan Intervention For Endpoint reduction in hypertension (LIFE) trial, in which hypertensive patients with ECG LV hypertrophy (Cornell voltage-duration product, > 2440 mm x ms and/or SV1 + RV(5-6) > 38 mm) were randomized to > or = 4 years double-blinded treatment with losartan or atenolol. PATIENTS/PARTICIPANTS: A total of 964 LIFE participants enrolled in an echocardiographic substudy, and groups of 282 employed hypertensive and 366 apparently normal adults. INTERVENTIONS: None. MAIN OUTCOME MEASURES: ECG LV parameters contributing to myocardial oxygen demand (wall stresses, LV mass, heart rate and wall stress-mass-heart rate products). RESULTS: In both women and men, stepwise increases from reference subjects to employed hypertensives to LIFE patients were observed for LV wall stresses, mass and stress-mass-heart rate products. LIFE men patients had slightly higher wall stresses and significantly higher triple products than women. Wall stresses were increased in patients with normal LV geometry, eccentric or concentric hypertrophy; triple products were about three and two times normal with eccentric and concentric hypertrophy, with smaller increases in other geometric groups. Patients with decreased LV fractional shortening had two times normal end-systolic stresses and three or four times normal triple products; smaller increases in stresses and triple products occurred with decreased LV midwall function. CONCLUSIONS: Hypertensive patients with ECG LV hypertrophy have increased LV wall stresses and stress-mass-heart rate products, suggesting a contribution of high myocardial oxygen demand to increased risk in such patients. Particularly high stresses and triple products were associated with echocardiographic LV hypertrophy, and subnormal LV chamber and midwall function.
