Early repolarization is involved in ventricular fibrillation in patients with variant angina.

BACKGROUND

Variant angina (VA) is caused by reversible coronary artery spasm, which is characterized by chest pain with ST segment elevations on a standard 12-lead electrocardiogram (ECG) at rest. VA attack often causes lethal ventricular arrhythmia. The early repolarization (ER) pattern is associated with ventricular fibrillation (VF). However, whether the ER pattern is involved in VF in patients with VA is not known. We investigated the association between the ER pattern and VF in patients with VA.

METHODS

Fifty patients underwent induction of ST elevation on 12-lead ECGs with total or nearly total occlusion by provocation test (VA patients). Twelve of these patients underwent induction of VF or had documented VF before hospital admission (VF occurrence group). The J-wave morphology was characterized as exhibiting notching or slurring. The amplitude of each J wave was measured manually with amplified waveforms.

RESULTS

ER patterns were observed significantly more often in the VF occurrence group than in the non-VF occurrence group (P = 0.007). The J-wave amplitude was significantly higher in the VF occurrence group compared with the non-VF occurrence group (P = 0.02). Univariate analyses suggested that age, smoking, and ER patterns were associated with VF. Upon multivariate analyses, age (odds ratio [OR] = 0.880; 95% confidence interval [CI]: 0.794-0.975; P = 0.014) and ER patterns (OR = 8.937; 95% CI:1.661-48.06; P = 0.011) predicted VF independently.

CONCLUSIONS

These data suggest that an ER pattern in VA patients is a risk factor for VF. The ER pattern may be one of the useful factors for adaptation of implantation of implantable cardioverter-defibrillator in patients with coronary spasm-induced VF.