Polyunsaturated fatty acid analogues differentially affect cardiac Nav, Cav, and Kv channels through unique mechanisms

The cardiac ventricular action potential depends on several voltage-gated ion channels, including Nav, Cav, and Kv channels. Mutations in these channels can cause Long QT Syndrome (LQTS) which increases the risk for ventricular fibrillation and sudden cardiac death. Polyunsaturated fatty acids (PUFAs) have emerged as potential therapeutics for LQTS because they are modulators of voltage-gated ion channels. Here we demonstrate that PUFA analogues vary in their selectivity for human voltage-gated ion channels involved in the ventricular action potential. The effects of specific PUFA analogues range from selective for a specific ion channel to broadly modulating all three cardiac ion channels (NaV, CaL, and IKs). In addition, PUFA analogues do not modulate these channels through a shared mechanism. Our data suggest that different PUFA analogues could be tailored towards specific forms of LQTS, which are caused by mutations in distinct cardiac ion channels, and thus restore a normal ventricular action potential.