What variables were associated with the inducibility of ventricular fibrillation during electrophysiologic stimulation test in patients without apparent organic heart disease?

Abstract

Objective: The purpose of our study was to determine what variables were associated with ventricular fibrillation (VF) induced during electrophysiological stimulation test in patients without apparent organic heart disease.

Methods: Our study evaluated 77 patients (51+/-15 years) who underwent electrophysiological stimulation test, signal averaging, and Na+ channel-blocker challenge test (pilsicainide test). The subjects were divided into two groups, the Brugada group and non-Brugada group. Further, the patients were divided into three subgroups on the base of symptoms (8, 7 symptomatic; 9, 13 syncope; 28, 12 asymptomatic group; in the Brugada and non-Brugada groups, respectively). Multivariate analyses evaluated the association between baseline clinical factors and the induction of VF.

Results: The inducibility of VF was significantly (p<0.0001) higher in the Brugada group (n=33, 73%) than the non-Brugada group (n=4, 13%). The multivariate analysis demonstrated that symptoms (odds ratio (OR) 31.6; 95% confidence interval (CI): 2.3-430.6; p<0.01), type 1 electrocardiogram after pilsicainide test (OR 21.3; CI: 1.7-272.2; p<0.02), and syncope (OR 13.5; CI: 1.2-158.8; p<0.05) were strongly associated with the inducibility of VF, but not with family history, type 1 electrocardiogram in control, positive in late potential, maxDeltaST elevation (>==200microV) after pilsicainide test.

Conclusions: The symptoms, syncope, and type 1 electrocardiogram after pilsicainide test were independently associated with the electrophysiological substrate of VF in patients without apparent heart disease.