Pharmacological Assessment in Young Patients with J-Wave Variation and Idiopathic Ventricular Fibrillation

Background: Little information is available regarding pharmacological management in patients with idiopathic ventricular fibrillation (IVF). A recent study has shown J-wave variation is risk-stratifying factor in young IVF patients. In this study, we assessed clinical impact of J-wave variation on pharmacological therapy in such subjects. Methods: We enrolled 8 consecutive young IVF patients (26±8 years, 5 men) who had real life-threatening events. Patients with Brugada-type electrocardiograms (ECGs) were excluded. J wave was defined as >1.0 mm elevation at the J point on 12-lead ECGs. J-wave variation was defined positive if it is >1.0 mm in difference of J-wave amplitude on 24-hr Holter ECGs. Results: Of the 8 patients, five (63%) had J waves on 12-lead ECGs. Among five patients, two (25%) had significant J-wave variation over 24 hours and the remaining three did not. In two patients with J-wave variation, pharmacological therapy including class III antiarrhythmic drugs and β-blockers are ineffective. However, β-blockers were effective in two of three patients without J waves and in two of three patients without J-wave variation on 12-lead and Holter ECGs. Conclusion: In young IVF patients with J-wave variation, pharmacological therapy is ineffective and implantable defibrillator therapy would be strongly desirable.