[QT interval variability in adjacent areas on standard ecg during ectopic activity in patients with acute coronary syndrome].

Clinical and experimental evidence closely link malignant ventricular arrhythmia with increased dispersion of refractoriness and thus electrical heterogeneity in different kinds of heart diseases. Most increased dispersion of refractoriness is due to inhomogenous action potential duration in adjacent areas, decreased local conduction velocity or both. The article focuses on ectopic ventricular activity and on QT interval variability in adjacent segments on standard ECG in patients with acute coronary syndrome. The adjacent QT dispersion was defined as a difference between two adjacent leads. Seventy nine patients aged 54+/-6,5 in 6 hour interval after the attack with elevation of ST segments on ECG were studied. Fifteen patients aged 48+/-7 without elevation of ST segment on ECG served as control subjects. Patients were allocated to two groups: one included patients with 1-2 ectopic degree; group two included patients with 3-5 ectopic degree. In patients with acute coronary syndrome QT max and QTd was significantly higher than in control subjects (p<0,05). The increase of ventricular ectopic degree is linked with the increased adjacent QT dispersion.