[Dispersion of QT interval in arterial hypertension with left ventricular hypertrophy]

QT interval dispersion (QTD) is considered to reflect the inhomogeneity of ventricular repolarization. Increased QTD has been shown to be positively correlated to complex ventricular arrhythmias (CVA) in many clinical conditions. The aim of this study was to assess QTD in arterial hypertension with left ventricular hypertrophy (LVH) and to verify the possible relationship between increased QTD and the presence of CVA in this population. We studied 100 patients with essential arterial hypertension, aged 25-78 years, mean 53. Half of the patients had LVH (group A); LVH was defined as diastolic septal thickness of 1.2 cm or more (by echocardiography). The septum was 1.1 cm or less in the patients without LVH (group B). QTc intervals were measured on the 12-lead surface ECG; QTD was defined as the difference between the longest and the shortest QTc. The presence of Lown class 2 (or more) ventricular arrhythmias on a 24-hour Holter monitoring was considered CVA. In the 100 patients studied, QTD ranged from 10 to 128 ms, mean 43.7 ms. It was longer in group A than in group B; 56.1 ms versus 51.5 ms (mean values). 14 patients in group A had CVA; they had a shorter QTD than patients without CVA: 51.2 ms versus 57.9 ms. In patients with essential arterial hypertension the presence of LVH is positively correlated to increased QTD. Increased QTD however does not seem to be an adjunctive risk factor for CVA in is population.