[Association between electrocardiogram characteristics and long-term outcome in patients with idiopathic ventricular...

To explore the association between clinical and ECG characteristics and prognoses in patients with idiopathic ventricular fibrillation (VF).

We reviewed the data from 21 VF patients [male 47.6%, mean age (38.5 ± 19.0) years] with first event of VF, all patients were resuscitated after cardiac arrest and diagnosed as idiopathic VF. The prevalence of J wave was assessed and patients were divided into J wave positive (J+ group) and negative group (J- group). The end point was death or syncope from arrhythmia, and recorded VF recurrence during the follow-up.

J wave was frequent in subjects with idiopathic VF (71.4%). Among patients in the J+ group (15 cases), notch on the QRS wave was found in 7 subjects (46.7%), these patients were more likely to suffer from the sudden cardiac arrest during sleep at early morning than those with J wave but without notch on the QRS wave. Two patients dead suddenly in the J+ group and 1 dead from embolism in the J- group during follow-up [mean (42.4 ± 39.9) months]. The mean year-onset of VF or syncope was significantly higher in the J+ group than in the J-group [(1.3 ± 0.5) episodes/year vs. (0.4 ± 0.3) episodes/year, P < 0.01]. J wave positive was also associated with an increased risk of VF recurrence (RR 1.9, 95%CI 1.1 to 2.9, P = 0.03).

J wave prevalence is high in patients with history of idiopathic VF, and positive J wave is associated with high risk of recurrence of sudden cardiac death.