In the study, there has been retrospectively analyzed heart rate turbulence in postinfarction patients. The cohort of 158 patients consisted of 94 patients with documented ventricular tachycardia and/or ventricular fibrillation (VT/VF) and 64 patients without history of VT/VF. Turbulence onset and slope were calculated from Holter recordings, and left ventricle ejection fraction (LVEF) ≤35% was regarded as severe left ventricle dysfunction. Study groups were similar in age and sex. Left ventricle ejection fraction was lower in the VT/VF group (P < .005). Patients with VT/VF had higher turbulence onset (-0.22% ± 1% vs -0.8% ± 2%; P = .005) and lower turbulence slope (2.6 ± 1.9 vs 4.1 ± 3.5 milliseconds per RR interval; P = .01). These trends were observed in patients with LVEF >35% but not in subjects with LVEF ≤35%. Diabetes mellitus, previous coronary artery bypass graft, and amiodarone therapy have diminished the intergroup differences significantly.
Conclusions: Heart rate turbulence is diminished in postinfarction patients with a history of malignant ventricular arrhythmias. It seems to separate subjects at arrhythmic risk among patients with relatively preserved left ventricle function, but it is diminished in patients with previous coronary artery bypass graft, diabetes, and amiodarone therapy.
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