Raised plasma non-esterified fatty acids (NEFA) during ischaemia: implications for arrhythmias

Raised plasma non-esterified fatty acids (NEFA) have been directly implicated in the development of serious ventricular arrhythmias and death during acute myocardial infarction. Since this was first proposed by Oliver and Kurien in 1970, clinical and experimental evidence has been conflicting, but results of clinical studies with antilipolytic drugs suggested a reduction in ventricular tachycardia. Lowering of raised NEFA by antilipolytic therapy in dogs was effective, whilst raising NEFA, either by intravascular lipolysis or direct infusion, failed to precipitate VF. An alternative hypothesis is proposed, which suggests that a fatty acid--triglyceride energy wasting cycle operates at different rates within the ischaemic heart, and caused differential rates of K+ loss, leading to ventricular fibrillation.