To investigate whether suppression of ventricular premature beats (VPBs) in patients following myocardial infarction (MI) reduced their risk of sudden death, patients were assigned to the Na+ channel/INa blockers, encainide, flecainide, moricizine, or placebo (flecainide also has some hERG/IKr-blocking effects, but INa blockade is pharmacodynamically more important). This evidence concerns the gene INA and myocardial infarction.