Digoxin atrial fibrillation

Digoxin Atrial fibrillation and flutter with rapid ventricular response Adenosineldiopathic and re-entrant paroxysmal supraventricular tachycardia WPW, Wolf-Parkinson-White. 

Dlgltoxin. Digitoxin is a cardiac glycoside obtained from Digitalis purpurea. Digitoxin is indicated in the treatment of atrial flutter, atrial fibrillation, and supraventricular tachycardia. Its electrophysiologic and adverse effects are similar to those described for digoxin (87). 

Current recommendations are for the addition of digoxin for patients who remain symptomatic despite an optimal HF regimen consisting of an ACE inhibitor or ARB, (3 -blocker, and diuretic. In patients with concomitant atrial fibrillation, digoxin may be added to slow ventricular rate regardless of HF symptomology. 

A 59-year-old male with a history of rheumatic heart disease is found to have atrial fibrillation (AF for which he is treated with digoxin. Treatment with digoxin converts his AF to a normal sinus rhythm and most likely results in a decrease in which of the following ... 

In patients with HF and supraventricular tachyarrhythmias such as atrial fibrillation, digoxin should be considered early in therapy to help control ventricular response rate. 

Homestam, B., Jerling, M., Karlsson, M.O., and Held, P. DAAf Trial Group, Intravenously administered digoxin in patients with acute atrial fibrillation a population pharmacokinetic/pharmacodynamic analysis based on the digitalis in acute atrial fibrillation trial, Eur.. Clin. Pharmacol., 58, 747-755, 2003. 

R4. Redfors, A., Plasma digoxin concentration—its relation to digoxin dosage and clinical effects in patients with atrial fibrillation. Brit. Heart J. 34, 383-391 (1972). 

Atrial fibrillation Peak digoxin body stores larger than the 8 to 12 mcg/kg required for most patients with heart failure and normal sinus rhythm have been used for control of ventricular rate in patients with atrial fibrillation. Titrate doses of digoxin used for the treatment of chronic atrial fibrillation to the minimum dose that achieves the desired ventricular rate control without causing undesirable side effects. Data are not available to establish the appropriate resting or exercise target rates that should be achieved. 

Electrical cardioversion It may be desirable to reduce the dose of digoxin for 1 to 2 days prior to electrical cardioversion of atrial fibrillation to avoid the induction of ventricular arrhythmias, but physicians must consider the consequences of increasing the ventricular response if digoxin is withdrawn. If digitalis toxicity is suspected, delay elective cardioversion. If it is not prudent to delay cardioversion, select the lowest possible energy level to avoid provoking ventricular arrhythmias. Lab test abnormalities Periodically assess serum electrolytes and renal function (serum creatinine concentrations) the frequency of assessments will depend on the clinical setting. 

As with other Class I agents, patients treated with flecainide for atrial flutter have been reported with 1 1 atrioventricular conduction due to slowing the atrial rate. A paradoxical increase in the ventricular rate also may occur in patients with atrial fibrillation who receive flecainide. Concomitant negative chronotropic therapy such as digoxin or beta-blockers may lower the risk of this complication. 

Another important, in fact more convincing indication for the use of digoxin is atrial fibrillation, in particular when occurring after cardiac surgery. The beneficial effect of digoxin is caused by impairment of the AV conduction, leading to the dissociation of the electrical activities of the atria and the ventricles. The inotropic effect, although weak, is potentially useful. 

Digoxin, prototype of the cardiac glycosides, is frequently used postoperatively for the management of atrial fibrillation. This effect is based on the impairment of AV conduction and unrelated to digoxin s positive inotropic activity. In the treatment of post-operative atrial fibrillation digoxin may be... 

Intravenous digitalization is done in emergency conditions of CHF or in atrial fibrillation. Digoxin 0.25 mg followed by 0.1 mg hourly be given by slow IV route with close monitoring of cardiac function. 

Digitalis (DIGOXIN) 0.25-0.5 mg IV for paroxysmal supraventricular tachycardia (PSVT), atrial flutter and atrial fibrillation... 

Supraventricular tachycardia is the major arrhythmia indication for verapamil. Adenosine or verapamil are preferred over older treatments (propranolol, digoxin, edrophonium, vasoconstrictor agents, and cardioversion) for termination. Verapamil can also reduce the ventricular rate in atrial fibrillation and flutter. It only rarely converts atrial flutter and fibrillation to sinus rhythm. Verapamil is occasionally useful in ventricular arrhythmias. However, intravenous verapamil in a patient with sustained ventricular tachycardia can cause hemodynamic collapse. 

Treatment of atrial fibrillation is initiated to relieve patient symptoms and prevent the complications of thromboembolism and tachycardia-induced heart failure, the result of prolonged uncontrolled heart rates. The initial treatment objective is control of the ventricular response. This is usually achieved by use of a calcium channel-blocking drug alone or in combination with a 13-adrenergic blocker. Digoxin may be of value in the presence of heart failure. A second objective is a restoration and maintenance of normal sinus rhythm. Several studies show that rate control (maintenance of ventricular rate in the range of 60-80 bpm) has a better benefit-to-risk outcome than rhythm control (conversion to normal sinus rhythm) in the long-term health of patients with atrial fibrillation. If rhythm control is deemed desirable, sinus rhythm is usually restored by DC cardioversion in the USA in... 

Digoxin is indicated in patients with heart failure and atrial fibrillation. It is also most helpful in patients with a dilated heart and third heart sound. It is usually given only when diuretics and ACE inhibitors have failed to control symptoms. Only about 50% of patients with normal sinus rhythm (usually those with documented systolic dysfunction) will have relief of heart failure from digitalis. Better results are obtained in patients with atrial fibrillation. If the decision is made to use a cardiac glycoside, digoxin is the one chosen in most cases (and the only one available in the USA). When symptoms are mild, slow loading (digitalization) with 0.125-0.25 mg per day is safer and just as effective as the rapid method (0.5-0.75 mg every 8 hours for three doses, followed by 0.125-0.25 mg per day). 

Digoxin Na +, K+ ATPase inhibition results in reduced Ca2+ expulsion and increased Ca2+ stored in sarcoplasmic reticulum Increases cardiac contractility cardiac parasympathomimetic effect (slowed sinus heart rate, slowed atrioventricular conduction) Chronic symptomatic heart failure rapid ventricular rate in atrial fibrillation Oral, parenteral duration 36-40 h Toxicity Nausea, vomiting, diarrhea cardiac arrhythmias... 

Falk RH, et al. Digoxin for converting recent-onset atrial fibrillation to sinus rhythm. A randomized, double-blinded trial. Ann Intern Med 1987 106(4)503-506. 

Jordaens L, et al. Conversion of atrial fibrillation to sinus rhythm and rate control by digoxin in comparison to placebo. Eur Heart J 1997 18(4) 643-648. 

In some cases of atrial fibrillation, both digoxin and verapamil are used (324,325). Observations from this coadministration have shown how P-gp modulation by verapamil altered the distribution and elimination of digoxin (214,331-335). 

Lanoxicap Digoxin 50, 100, 200 (jLg SEC Heart failure, atrial fibrillation Na-K ATPase inhibitor PEG 400, ethyl alcohol, propylene glycol, purified water GSK... 

Digoxin (see p. 158) shortens the refractory period in atrial and ventricular myocardial cells while prolonging the effective refractory period and diminishing conduction velocity in Purkinje fibers. Digoxin is used to control the ventricular response rate in atrial fibrillation and flutter. At toxic concentrations, digoxin causes ectopic ventricular beats that may result in ventricular tachycardia and fibrillation. [Note This arrhythmia is usually treated with lidocaine or phenytoin.]... 

Digitalis glycosides augment contractile force and are likewise used in severe forms of insuf ciency, specifically in the presence of concomitant atrial fibrillation. Because of the narrow margin of safety, the digoxin dose must be adjusted individually in each patient. 

Hannah s ECG shows an abnormal heart beat she has now developed atrial fibrillation. Hannah is prescribed digoxin and an anticoagulant, warfarin. 

Digoxin is a cardiotonic agent with a narrow therapeutic index which is used to treat atrial fibrillation since it not only increases cardiac contractility but also acts on vagal centres in the brain and beneficially slows the heart. A slow heart facilitates coronary perfusion and ventricular filling, which improves cardiac output. 

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