Intravenous infusion of n-3 polyunsaturated fatty acids and inducibility of ventricular tachycardia in patients with implantable cardioverter defibrillator

Abstract

Marine n-3 polyunsaturated fatty acids (PUFA) may have antiarrhythmic effects. The aim of this study was to investigate the effect of intravenously administered n-3 PUFA on the inducibility of ventricular tachycardia (VT) in patients with an implantable cardioverter defibrillator (ICD). In a randomized, placebo-controlled cross-over study, patients with an ICD underwent two electrophysiological studies using the stimulation possibilities in the ICD preceded by intravenous infusion of either a lipid emulsion delivering 3.9 g n-3 PUFA or placebo (0.9% saline). The level of stimulation required to induce sustained monomorphic VT was ranked in order from least to most aggressive, and non-inducibility was ranked highest. The content of n-3 PUFA in plasma free fatty acids (FFA), plasma phospholipids, and platelet phospholipids was measured by gas chromatography. Eight patients were included, and six of these completed the study. The content of n-3 PUFA as FFA and in platelet phospholipids increased more after n-3 PUFA infusion than after placebo (P<0.001). Of the five patients who were inducible after placebo, two were no longer inducible after n-3 PUFA infusion and another two required stronger stimulation to induce VT. The difference in the stimulation required after placebo and after n-3 PUFA was borderline significant (P=0.063, Wilcoxon signed-rank test). Intravenous n-3 PUFA tended to decrease VT inducibility, but a larger study is warranted.