Although MYPN mutations have been reported in various cardiomyopathies, their association with arrhythmogenic phenotypes and malignant ventricular arrhythmias remains poorly characterized.<h4>Case summary</h4>A 25-year-old man developed ventricular fibrillation (VF) while at a golf driving range. The gene discussed is MYPN; the disease is cardiomyopathy.