Relationship of the electrocardiographic strain pattern to left ventricular structure and function in hypertensive patients: The LIFE study

OBJECTIVES This study was designed to assess the relation of electrocardiog raphic (ECG) strain to increased left ventricular (Ly mass, independent of its relation to coronary heart disease (CHD). BACKGROUND The classic ECG strain pattern, ST depression and T-wave inversi on, is a marker for left ventricular hypertrophy (LVH) and adverse prognosi s. However, the independence of the relation of strain to increased LV mass from its relation to CHD has not been extensively examined. METHODS Electrocardiograms and echocardiograms were examined at study basel ine in 886 hypertensive patients with ECG LVH by Cornell voltage-duration p roduct and/or Sokolow-Lyon voltage enrolled in the Losartan Intervention Fo r End point (LIFE) echocardiographic substudy. Strain was defined as a down sloping convex ST segment with inverted asymmetrical T-wave opposite to the QRS axis in leads V-5 and/or V-6. RESULTS Strain occurred in 15% of patients, more commonly in patients with than without evident CHD (29%, 51/175 vs. 11%, 81/711, p < 0.001). When dif ferences in gender, race, diabetes, systolic pressure, serum creatinine and high density lipoprotein cholesterol were controlled, strain on baseline E CG was associated with greater indexed LV mass in patients with (152 +/- 33 vs. 131 +/- 32 g/m(2), p < 0.001) or without CHD (131 +/- 24 vs. 119 +/- 2 2 g/m(2), p < 0.001). In logistic regression analyses, strain was associate d with an increased risk of anatomic LVH in patients with CHD (relative: ri sk 5.14, 95% confidence interval (CI] 1.16 to 22.85, p = 0.0315), without e vident CHD (relative risk 2.91, 95% CI 1.50 to 5.65, p = 0.0016), and in th e overall population when CHD was taken into account (relative risk 2.98, 9 5% CI 1.65 to 5.38, p = 0.0003). CONCLUSIONS When clinical evidence of CHD is accounted for, ECG strain is l ikely to indicate the presence of anatomic LVH. Greater LV mass and higher prevalence of LVH in patients with strain offer insights into the known ass ociation of the strain pattern with adverse outcomes. (J Am Coll Cardiol 20 01;38:514-20) (C) 2001 by the American College of Cardiology.