Vorhofflimmern findet sich bei ca. 0,4 % aller Erwachsenen (15, 20), die Häufigkeit nimmt mit dem Alter exponentiell zu (Abb. 1) und erreicht für über 60jährige 2 % – 4 % (4, 13, 15, 19 – 21). Bei einem Alter von über 66 Jahren wurde eine Inzidenz von bis zu 9 % beschrieben (13). Bei Männern fand sich bei gleichem Alter Vorhofflimmern zumeist häufiger als bei Frauen (4, 12, 15, 18, 20).

We studied the effect of barucainide, an investigational class lb antiarrhythmic drug, on ventricular arrhythmias and left-ventricular ejection fraction in 10 patients with frequent and complex ventricular arrhythmias (Lown grade 4a/4b). The study was conducted as a single-blind and placebo-controlled trial. With placebo, mean frequency of ventricular arrhythmias was 6238 VPB/24 h, 510 couplets/24 h, and 24 salvos/24 h. Mean left-ventricular ejection fraction was 37.6%, ranging from 18% to 58%. Therapy with barucainide (300-400 mg/day) resulted in a significant reduction of ventricular arrhythmias in 7 of 10 patients; in one patient barucainide had a clear proarrhythmic effect. Over all, left-ventricular ejection fraction (37.6% +/- 12% with placebo vs 36.1% +/- 11% with barucainide) was not significantly altered. In one patient, however, it was depressed by more than 5%; one patient complained of shortness of breath during exercise. None of the four patients with an initial ejection fraction below 35% showed a drop of ejection fraction during therapy with barucainide. The only main adverse effect was a small, but significant (p less than 0.005) rise of serum-kreatinine (1.13 +/- 0.26 vs 1.39 +/- 0.38 mg%) in all patients. We conclude that barucainide has a good antiarrhythmic effect and is usually well tolerated in patients with markedly depressed left-ventricular function. The mechanism causing the rise of serum-kreatinin, however, needs to be clarified in further studies.

Enoximone, a phosphodiesterase-inhibitor, is a potent inotropic vasodilator agent that causes a marked improvement in hemodynamics in patients with congestive heart failure. The acute effects of oral enoximone on rest and exercise hemodynamics, ejection fraction, aerobic metabolism, exercise capacity, and arrhythmias were studied in 11 patients with moderate to moderately severe dilative cardiomyopathy after 8 days of enoximone (100 mg tid) in addition to baseline therapy (diuretics and digitalis).

The controversy concerning clinical efficacy, the inotropic effects of low doses in experiments, and the risk of toxicity have led to the use of lower dosages in clinical practice. Studies supporting this attitude are not available.

Bei 8 Patienten mit intermittierendem Vorhofflimmern bzw. rezidivierenden supraventrikulären Tachykardien wurde der Einfluß von Chinidin (320 mg i.v.) sowie der Kombination Chinidin/ Verapamil (5 mg i.v.) auf die Sinusknotenautomatie, die intrakardialen Leitungszeiten und Refraktärzeiten mittels programmierter Stimulation und Hisbündelableitung untersucht.

In a prospective study of 10 patients with chronic ventricular arrhythmias, flecainide 50mg tid and propranolol 20mg tid were administered, alone and in combination, in a crossover design. Before and after each treatment phase, routine ECG and 24-hour ECG were recorded, morning plasma concentrations of the drugs were measured, and side effects recorded. Treatment with flecainide alone resulted in a 38% mean reduction (p < 0.05) of ventricular premature complexes, a 75% (p < 0.01) mean reduction of couplets, and elimination of ventricular tachycardia. At the dosage administered, propranolol alone had no antiarrhythmic effect. The combination of flecainide and propranolol showed no additional therapeutic benefit although there was a small, but not significant, increase in ventricular premature complexes and couplets. Use of flecainide resulted in a 12% widening of the QRS complex, with no significant change in PQ time, QTc and heart rate. Combined therapy with propranolol and flecainide resulted in a 12% decrease of average heart rate. The same effect was achieved when propranolol was given alone. The average plasma concentration of flecainide increased by 25% during combined therapy with propranolol. There were few side effects related to flecainide at the dosage administered and no additional side effects were recorded during the combined treatment.