Clinical Investigations Left ventricular hypertrophy (LVH) is considered as an independent risk factor for coronary artery disease (CAD) and cardiovascular complications. 1 It has been established that CAD, stroke, and sudden death are more frequent in patients with LVH. 2,3 Variations of the QT interval on the standard electro- cardiograph (ECG) have been associated with increased sudden death incidence in a middle-aged population 4 and in patients with CAD. 5,6 An increase in QT dispersion has been considered as predisposing to serious ventricular arrhythmias or sud- den death in hypertrophic cardiomyopathy, 7 congestive heart failure or dilated cardiomyopathy, 8 and coronary artery disease, 9 as well as after myocardial infarction. 10 An increased QT dispersion also has been found 11-13 in hypertensive patients with LVH. We assessed the behavior of QT dispersion after LVH regression. Previ- ous data on this subject are limited. 12 Methods We retrospectively studied 68 patients (42 men and 26 women, mean age 56.3 ± 9.5 years) with hypertension. All enrolled patients were without medication for at least 1 month before entrance in the study. To qualify for enroll- ment, sitting diastolic blood pressure (average of 3 readings) had to be measured from 95 to 110 mm Hg at rest. All were included in the study after a detailed clinical and laboratory examination for exclusion of serum electrolyte abnormalities. Patients with manifestations of CAD, arrhythmias, congestive heart failure, valvular heart disease, diabetes mellitus, renal Congestive Heart Failure Regression of left ventricular hypertrophy results in improvement of QT dispersion in patients with hypertension Eva A. Karpanou, MD, Gregory P. Vyssoulis, MD, Apostolos Psichogios, MD, Christina Malakou, MD, Elena A. Kyrozi, MSc, Dennis V. Cokkinos, MD, and Pavlos K. Toutouzas, MD Athens, Greece Objectives Increased QT dispersion has been considered as predisposing to ventricular arrhythmias in hypertrophic cardiomyopathy, congestive heart failure, and coronary artery disease. An increased QT dispersion has also been found in hypertensive patients with left ventricular hypertrophy (LVH). The data on the effect of LVH regression on QT dispersion are limited. Methods and Results To assess the relation of LVH regression and QT dispersion decrease, 68 patients (42 men and 26 women, mean age 56.3 ± 9.5 years) with uncomplicated essential hypertension were studied. All underwent full elec- trocardiographic and echocardiographic studies at baseline and after 6 months of monotherapy, 29 with angiotensin-convert- ing enzyme inhibitors and 39 with calcium antagonists. QT dispersion was calculated by subtracting the shortest QT from the longest QT, in absolute value (QTmax – QTmin). It was also corrected with Bazett’s formula (QTc dispersion). Left ventricular mass index was assessed according to the Devereux formula. After treatment, LVH decreased with both angiotensin-converting enzyme inhibitors (from 155 to 130 g/m 2 , P < .001) and calcium antagonists (156 to 133/92/m 2 , P < .001). QT dispersion decreased both after angiotensin-converting enzyme inhibitor treatment (from 82 to 63 ms) and calcium antagonist treatment (from 77 to 63 ms, both P < .001). There was a significant correlation of QT dispersion and left ventricular mass after therapy (r = 0.36, P < .005). There was a correlation of the degree of LVH and QT dispersion decrease (r = 0.27, P < .05). Conclusions It is concluded that LVH regression influences ∆QT favorably. Its prognostic value has yet to be deter- mined. (Am Heart J 1998;136:765-8.) From the First Cardiology Department, Onassis Cardiac Surgery Center and Cardi- ology Department, Hippokrateio General Hospital, University of Athens. Submitted Nov. 18, 1997; accepted March 18, 1998. Reprint requests: Eva A. Karpanou, MD, Onassis Cardiac Surgery Center, First Car- diology Department, 356 Sygrou Ave, 176 74 Athens, Greece. Copyright © 1998 by Mosby, Inc. 0002-8703/98/$5.00 + 0 4/1/90416