Early repolarization and positive T-wave alternans as risk markers for life-threatening arrhythmias in patients with vasospastic angina.

BACKGROUND

Several arrhythmogenic markers have been suggested as predictors for risk of life-threatening arrhythmias during symptom-free periods in vasospastic angina (VSA), but no definite conclusion has been drawn.

OBJECTIVE

To investigate prevalence of fatal ventricular tachyarrhythmia in VSA and its relation to appearance of early repolarization (ER) and positive T wave alternans (p-TWA) in patients with VSA during symptom-free periods.

METHODS

We studied 116 consecutive patients with chest pain who underwent an acetylcholine provocation test for VSA diagnosis. Patients were divided into two groups with positive (VSA group; 66 cases) and negative (control group; 50 cases) provocation test results. The presence of ER on electrocardiogram and the modified moving average analysis of TWA during symptom-free periods were explored.

RESULTS

The incidences of ER and p-TWA were higher in the VSA than in the control group (P=0.001 and P=0.006, respectively). Multivariate analysis revealed that ER and p-TWA were independent predictors of VSA (odds ratio, 5.65 and 4.94; 95% confidence interval: 1.11-28.9 and 1.22-19.9, respectively). The incidence of coexisting baseline ER and p-TWA was significantly higher in VSA patients with life-threatening arrhythmic events (3/3 vs. 6/38; P<0.001) than in those without.

CONCLUSIONS

VSA patients with arrhythmic events showed a high incidence of ER and p-TWA during symptom-free periods. Therefore, baseline ER and p-TWA may help to identify VSA patients at high risk for life-threatening arrhythmias.