[Conversion rate and prevention of recurrence of paroxysmal and sustained atrial fibrillation or atrial flutter with verapamil/quinidine].

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia, occurs in 0.4% of the adult population and in as many as 2% to 4% of those 60 years of age or older.

PATIENTS AND METHODS

We studied retrospectively 102 patients, 76 males, 26 females, mean age 56 +/- 12 years, with paroxysmal or sustained atrial fibrillation or atrial flutter (AFlut) treated with verapamil/quinidine (Cordichin) (dosage 3 to 5 times 1 tablet/day). Coronary artery disease was present in 39 patients, dilated cardiomyopathy in 8 patients, valvular disease in 16 patients and various etiologies were present in 13 patients. Twenty-six patients had no discernable heart disease ("Jone atrial fibrillation"). Patients with long QT-syndrome (QT-duration > or = 500 msec; QTc > or = 440 ms) were excluded from this study.

RESULTS

Using verapamil/quinidine conversion to sinus rhythm (SR) was possible in 64 patients (63%) within 2 +/- 1 day (range 1 to 6 days). The mean given dosage of quinidine was significantly higher in patients converted to sinus rhythm (762 +/- 129 mg) compared to those without successful conversion (638 +/- 161 mg) (p < 0.001). Diameter of left atrium and left ventricle as well as the degree of heart failure did not influence cardioversion rate significantly. During a mean follow-up of 34 +/- 32 months (range < 1 to 129 months), sinus rhythm remained constant in 28/64 patients (44%) with verapamil/quinidine in whom conversion to sinus rhythm was successful. During follow-up, side effects were present in 20/64 patients who were discharged with verapamil/quinidine: in 2 patients (2%) a torsade de pointes tachycardia was observed (1 patient died suddenly); gastrointestinal side effects were observed in 5 patients (5%); 4 patients had sinuatrial and 3 patients atrioventricular conduction disturbances. An increase in ventricular ectopic beats were present in 3 patients and allergic reactions occurred in 3 patients.

CONCLUSIONS

The present data show that verapamil/quinidine is effective in conversion of atrial fibrillation and atrial flutter to sinus rhythm and is associated with an acceptable efficacy rate in preventing recurrences of atrial fibrillation or flutter. Final conclusions concerning side effects are only possible in prospective studies that are ongoing at the present time.