To assess effect of ω-3 polyunsaturated fatty acids (PUFAs) on non-invasive predictors of sudden cardiac death (ventricular arrhythmias, QT duration and variability, late ventricular potentials [LVP], microvolt-level T-wave alternans [MTWA], and heart rhythm turbulence [HRT]) in patients with Q-wave myocardial infarction (MI) and ventricular heart rhythm disturbances (VHRD).

The study included 140 men aged 52.5+/-1.3 years with primary diagnosis of Q-wave MI and I-IV Lown grade VHRD. Patients were randomized in 2 groups: index group (A) and control group (B) consisted of 70 persons each. Patients of index and control groups were divided into another 2 groups by severity of arrhythmic syndrome: Al (n=39) and Bl (n=38) with I-III grade VHRDs; A2 (n=31) and B2 (n=32) with IV-V grade VHRDs. In index groups (Al and A2) ω-3 PUFA medicine was administered additionally to standard therapy at a dose of 1 g/day during 6 months. All patients underwent standard clinical examination and 24-hour Holter ECG monitoring on days 10-14 and in 6 months after MI.

Decreases of single and paired ventricular extrasystoles, ventricular tachycardia runs, total duration of myocardial ischemia were observed in patients of index groups Al and A2 after ω-3 PUFAs treatment. After 6 months of ω-3 PUFAs treatment significant QT shortening and increase of QTc variability were noted. Numbers of patients with LVP in Al and A2 groups decreased 21.3% (p<0.05) and 38.7% (p<0.0l), with HRT - 20.5% and 29.1% (p<0.05), with MTWA - 18% and 16.1% (p<0.01). In control groups the result was statistically insignificant.

Administration of 1 g/day of a prescription preparation of 90% ω-3 PUFAs in patients with primary Q-wave MI was associated with decrease of ventricular ectopy severity in patients with low and high grade VHRD and simultaneous reduction of total myocardial ischemia time. ω-3 PUFAs administration for 6 months had marked positive effect on QT duration and variability, LVP, HRT, MTWA.