Pharmacological Therapy for Fibrillations

Abstract

Human beings suffer from two different kinds of fibrillations: one is atrial fibrillation (AF) and the other is ventricular fibrillation (VF). AF is the most common sustained arrhythmia and VF is the most serious. Pharmacological cardioversion with conventional class I antiarrhythmic drugs is usually little help in terminating long-lasting AF. However, bepridil, a multi-channel blocker, alone or in combination with aprindine restored the sinus rhythm in about 70% of patients. The average time to conversion was one month, and cardioversion was associated with a significant increase in fibrillation cycle length. After cardioversion, atrial contraction recovered within one week, and sinus rhythm was maintained better than after conventional electrical cardioversion. Pharmacological cardioversion of long-lasting AF with bepridil could become a new therapeutic option targeting remodeled atria. Patients with idiopathic VF have a characteristic J wave and ST elevation along with a lower QT-RR slope and short QT interval at slower heart rates. Although an implantable cardioverter defibrillator (ICD) is the most reliable therapy for idiopathic VF, both bepridil and disopyramide normalized repolarization dynamics (slope of the QT-RR relationship) and reduced the frequency of spontaneous VF episodes and ICD shocks. Pharmacological therapy for cardioversion of persistent AF and prevention of idiopathic VF may play a key role in improving not only quantity but also quality of life.

Keywords

• Antiarrhythmic drug
• Atrial fibrillation
• Ventricular fibrillation
• Amiodarone
• Bepridil