Time of occurrence, duration, and ventricular rate of paroxysmal atrial fibrillation: the effect of digoxin.

Abstract

Since autonomic tone affects the likelihood of the occurrence and perpetuation of atrial fibrillation, variation of the rate of occurrence of attacks would be expected in parallel with the known diurnal variation of autonomic activity.5 In this study we noted the times of day that episodes of atrial fibrillation occurred. We also compared the ventricular rates at the onset of paroxysms, and noted the number of prolonged paroxysms, in patients with and without digoxin therapy. Patients and methodsWe selected Holter recordings showing paroxysmal atrial fibrillation in 72 consecutive patients who were being investigated for clinical reasons. All patients were in sinus rhythm at the start and end of the recordings, which lasted for 48 hours. For the purposes of this study paroxysmal atrial fibrillation was defined as the occurrence of at least five beats of supraventricular origin, with a totally irregular ventricular response, with no visible P or flutter waves, the arrhythmia lasting less than 24 hours. Seventy two patients (32 men and 40 women; mean age 72 (range 34-93) had arrhythmias which fulfilled these criteria. Associated diagnoses were as follows: none 45, ischaemic heart disease 12, sinoatrial disease 11, valvar heart disease two, hypertension two. Thirty one patients were taking digoxin, 11 were taking a ,B adrenergic blocker (five with digoxin), and nine were taking a calcium channel blocker (three with digoxin). We calculated the serum concentration of digoxin from the serum creatinine concentration and the body weight, using a nomogram based on the pharmacokinetics of digoxin.6 The calculated serum digoxin concentration was 0 ,ug/l in 41, up to 1 jg/l in 11, and over 1 jug/l in 20 patients.The time of onset of each paroxysm was noted together with the ventricular rate, calculated from the first 5-10 beats of each paroxysm. In the case of prolonged bouts of atrial fibrillation lasting 30 minutes or more, the duration of the attack and the ventricular rate immediately before it ended were noted.

Atrial Fibrillation: The New Epidemic of the Ageing World

“…71 Therapeutic concentrations of digoxin do not lower the frequency of episodes of paroxysmal AF or the duration of episodes of paroxysmal AF diagnosed by 24-hour AECGS. 73,74 Digoxin has been found to increase the duration of episodes of paroxysmal AF, a result consistent with its action in reducing the atrial refractory period. 73 Therapeutic concentrations of digoxin also do not prevent a rapid ventricular rate from occurring in patients with paroxysmal AF.…”

“…73,74 Digoxin has been found to increase the duration of episodes of paroxysmal AF, a result consistent with its action in reducing the atrial refractory period. 73 Therapeutic concentrations of digoxin also do not prevent a rapid ventricular rate from occurring in patients with paroxysmal AF. [73][74][75] After a brief episode of AF, digoxin increases the shortening that occurs in atrial refactoriness and predisposes to the reinduction of AF.…”

“…73 Therapeutic concentrations of digoxin also do not prevent a rapid ventricular rate from occurring in patients with paroxysmal AF. [73][74][75] After a brief episode of AF, digoxin increases the shortening that occurs in atrial refactoriness and predisposes to the reinduction of AF. 76 Therefore, digoxin should be avoided in patients with sinus rhythm with a history of paroxysmal AF.…”

Optimization of the Heart Rate Control in Atrial Fibrillation by Monitoring of the Digoxin Concentration in Elderly Patients

“…Кроме того, существуют данные, указывающие на то, что количество иных (не ассоциированных с фибрилляцией предсердий) на-рушений сердечного ритма при применении дигок-сина повышается в сравнении с контролем [6], а их симптомность уменьшается [7]. Описанные явления усугубляются при непредсказуемых превышениях те-рапевтической концентрации дигоксина, которая, в свою очередь, зависит от целого ряда факторов, плохо поддающихся контролю и коррекции (дисметаболи-ческие отклонения, нарушения функции почек и печени, сопутствующая терапия) [8,9].…”

Atrial Fibrillation: A Review of the Management in the Emergency Department

“…It is no more effective than placebo at restoring sinus rhythm, 3 and it may prolong duration of paroxysmal atrial fibrillation. 4 Some consider it first-line therapy in patients with AF and associated heart failure, but the delay in action limits its usefulness in the emergency department. The beta blockers-propranolol, metoprolol, labetolol, and esmolol-can all be used in the emergency setting to slow ventricular rates.…”