REGRESSION OF LEFT-VENTRICULAR HYPERTROPHY RESULTS IN IMPROVEMENT OF QT DISPERSION IN PATIENTS WITH HYPERTENSION

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 dispersio n has also been found in hypertensive patients with left ventricular h ypertrophy (LVH). The data on the effect of LVH regression on QT dispe rsion are limited. Methods and Results To assess the relation of LVH r egression and QT dispersion decrease, 68 patients (42 men and 26 women , mean age 56.3 +/- 9.5 years) with uncomplicated essential hypertensi on were studied. All underwent full electrocardiographic and echocardi ographic studies at baseline and after 6 months of monotherapy, 29 wit h angiotensin-converting enzyme inhibitors and 39 with calcium antagon ists. QT dispersion was calculated by subtracting the shortest QT from the longest QT, in absolute value (QTmax - QTmin). It was also correc ted with Bazett's formula (QTc dispersion). Left ventricular mass inde x was assessed according to the Devereux Formula. After treatment, LVH decreased with both angiotensin-converting enzyme inhibitors (from 15 5 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 c orrelation of QT dispersion and left ventricular mass after therapy (r = 0.36, P < .005). There was a correlation of the degree of LVH and Q T dispersion decrease (r = 0.27, P < .05). Conclusions It is concluded that LVH regression influences Delta QT favorably. Its prognostic val ue has yet to be determined.