Effect of quinidine on maintaining sinus rhythm after conversion of atrial fibrillation or flutter. A multicentre study from Stockholm.

Abstract

In a controlled study comprising 176 patients, quinidine in the form of Kinidin Durules was found to reduced significantly the recurrence of the atrial fibrillation during a 1-year follow-up period after successful electric shock conversion. After one year, 51 per cent (52/101) of the patients in the quinidine group, and 28 per cent (21/75) in the control group remained in sinus rhythm (P smaller than 0.001). No less than 43 per cent of the patients converted to sinus rhythm during treatment with maintenance doses of quinidine sulphate before intended DC conversion. Gastrointestinal side-effects were not uncommon, and caused interruption of quinidine treatment in some cases.

Efficacy and safety of quinidine therapy for maintenance of sinus rhythm after cardioversion. A meta-analysis of randomized control trials.

“…In three papers, details of the duration of AF in the two treatment groups were provided, and there were no significant differences in the duration of AF between the quinidine and control groups in any of those trials. 19,20,22 The various cardiac diagnoses and possible etiologies of AF in each studiy are shown in Table 2.…”

2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

“…Sotalol, but not quinidine, reduced heart rate in patients with recurrent AF, and there were fewer symptoms with sotalol. 535,592,614,[617][618][619][620][621][622][623][624] In 2 European multicenter studies, the combination of quinidine plus verapamil was as effective as or superior to sotalol in preventing recurrences of paroxysmal and persistent AF. In the Suppression Of Paroxysmal Atrial Tachyarrhythmias (SOPAT) trial, 625 1033 patients (mean age 60 y, 62% male) with frequent episodes of symptomatic paroxysmal AF either received high-dose quinidine (480 mg per day) plus verapamil (240 mg per day; 263 patients), low-dose quinidine (320 mg per day) plus verapamil (160 mg per day; 255 patients), sotalol (320 mg per day; 264 patients), or placebo (251 patients).…”

“…698 Restoration and maintenance of sinus rhythm are less likely when AF has been present for longer than 1 y than in patients with AF of shorter duration. The variation in immediate success rates for direct-current cardioversion from 70% to 99% in the literature 617,682,684,700,701 is partly explained by differences in patient characteristics and the waveform used but also depends upon the definition of success, because the interval at which the result is evaluated ranges from moments to several days. Over time, the proportion of AF caused by rheumatic heart disease has declined, the average age of the AF population has increased, 700 -702 and the incidences of lone AF have remained constant, making it difficult to compare the outcome of cardioversion across various studies.…”

“…698 When quinidine (600 to 800 mg 3 times daily for 2 d) failed to convert the rhythm, there was no difference in defibrillation threshold between patients randomized to continue or withdraw the drug. 617 …”

The drug treatment of atrial fibrillation.

“…When prophylaxis is required chronic oral therapy with flecainide (Anderson et al, 1989;Van Gelder et al, 1989), propafenone (Hammill et al, 1988;Kerr et al, 1988;Porterfield & Porterfield, 1989) amiodarone (Blevins et al, 1987;Brodsky et al, 1987;Gold et al, 1986), sotalol (Antman et al, 1990) or quinidine (Hillestad et al, 1971;Sodermark et al, 1975) are effective in maintaining sinus rhythm in about 50-70%/-of cases when compared with placebo or no active treatment. The long term safety of these drugs in patients with paroxysmal atrial fibrillation needs to be established since all have pro-arrhythmic tendencies.…”