J wave is associated with increased risk of sudden cardiac arrest in patients with hypertrophic cardiomyopathy

Aims A retrospective, case–control study to investigate the J wave, a J-point elevation on resting 12-lead electrocardiograms, as a risk factor for sudden cardiac arrest (SCA) in patients diagnosed with hypertrophic cardiomyopathy (HCM). Methods Patients with HCM and age- and sex-matched healthy control subjects were recruited, and 12-lead electrocardiograms were performed. The prevalence and related characteristics of J waves were assessed. Patients were followed-up for a mean of 47.9 months. Results Patients with HCM ( n = 345) had significantly higher prevalence of J waves than healthy controls ( n = 690; 11.6% and 7.1%, respectively). During follow-up, 14 patients with HCM experienced SCA (SCA subgroup). The prevalence of J waves was significantly higher in the SCA subgroup than in the non-SCA subgroup (42.9% and 10.3%, respectively). There were no significant differences between the SCA and non-SCA subgroups in J wave morphology. Conclusion The J wave may be a risk factor for SCA in patients with HCM.