Which is the preferred treatment for atrial fibrillation with a rapid ventricular rate?

1.

Calkins, Hugh, Tomaselli, Gordon F., Morady, Fred (2022). In Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine (pp. 1272). DOI: 10.1016/B978-0-323-72219-3.00066-9

Patients who present to the emergency department because of AF often have a rapid ventricular rate, and control of the ventricular rate is most rapidly achieved with intravenous diltiazem or esmolol (eTable 66G.3). If the patient is hemodynamically unstable, immediate transthoracic cardioversion may be appropriate. Cardioversion should ideally be preceded by TEE to rule out a left atrial thrombus if the AF has been present for longer than 48 hours or if the duration is unclear and the patient is not already anticoagulated. However, if the patient has marked hemodynamic compromise, immediate cardioversion without a TEE is advised. If the patient is hemodynamically stable, the decision to restore sinus rhythm by cardioversion is based on several factors, including symptoms, prior AF episodes, age, left atrial size, and current AAD therapy. For example, in an elderly patient whose symptoms resolve oncethe ventricular rate is controlled and who already has had early recurrences of AF despite rhythm-control drug therapy, further attempts at cardioversion usually are not appropriate. On the other hand, cardioversion usually is appropriate for patients with symptomatic AF who present with a first episode of AF or who have had long intervals of sinus rhythm between prior episodes. If cardioversion is decided upon for a hemodynamically stable patient who presents with AF that does not appear to be self-limited, two management decisions must be made: early versus delayed cardioversion and pharmacologic versus electrical cardioversion. The advantages of early cardioversion are rapid relief of symptoms, avoidance of the need for TEE or therapeutic anticoagulation for 3 to 4 weeks before cardioversion if cardioversion is performed within 48 hours of AF onset, and possibly a lower risk of early AF recurrence because of less atrial remodeling (seeChapter 64). A reason to defer cardioversion is the unavailability of TEE in a patient who has not been anticoagulated with AF of unclear duration or duration more than 48 hours.

Patients with the WPW syndrome and an accessory pathway with a short refractory period can experience a very rapid ventricular rate during AF (seeChapters 64 and 65Chapter 64Chapter 65). Ventricular rates greater than 250 to 300 beats/min can result in loss of consciousness or precipitate ventricular fibrillation and a cardiac arrest. Patients with WPW syndrome who present in AF with a rapid ventricular rate should undergo transthoracic cardioversion if there is hemodynamic instability. If the patient is hemodynamically stable, intravenous procainamide or ibutilide can be used for pharmacologic cardioversion. Procainamide may be preferable to ibutilide because it blocks accessory pathway conduction and slows the ventricular rate before AF has converted to sinus rhythm. Digitalis and calcium channel antagonists are contraindicated in patients with WPW syndrome and AF. These agents selectively block conduction in the AV node and can result in acceleration of conduction through the accessory pathway. The preferred therapy for patients with WPW syndrome and AF with a rapid ventricular rate is catheter ablation of the accessory pathway. When performed by experienced operators, the efficacy of catheter ablation is 95% or higher for most types of accessory pathways, and the risk of a major complication is very low. AF typically no longer recurs after successful accessory pathway ablation, probably because AF in the WPW syndrome often is induced by AV reciprocating tachycardia that degenerates into AF (seeeTable 66G.6).

An excessively rapid ventricular rate during AF often results in uncomfortable symptoms and decreased effort tolerance and can cause a tachycardia-induced cardiomyopathy if it is sustained for several weeks to months. Optimal heart rates during AF vary with age and should be similar to the heart rates that a patient would have at a particular degree of exertion during sinus rhythm. Heart rate control must be assessed both at rest and during exertion. The 2014 and 2019 ACC/AHA/HRS AF Guidelines advise that the optimal metric for rate control is a resting heart rate <80 beats/min.,Based on a single European clinical trial, a more lenient rate control metric of <110 beats/min is provided with a class IIb recommendation.,Assessment of the degree of heart rate control can be obtained with a 24-hour Holter monitor. A 12-lead ECG provides an indication of the resting ventricular rate but fails to provide information on the ventricular rate during a patient’s daily activities. Oral agents available for long-term heart rate control in patients with AF are digitalis, beta blockers, calcium channel antagonists, and amiodarone(seeChapter 64). The first-line agents for rate control are beta blockers and the calcium channel antagonists verapamil and diltiazem. A combination is often used to improve efficacy or to limit side effects by allowing the use of smaller dosages of the individual drugs. In patients with sinus node dysfunction and tachycardia-bradycardia syndrome, the use of a beta blocker with intrinsic sympathomimetic activity (pindolol, acebutolol) may provide rate control without aggravating sinus bradycardia. Digitalis may adequately control the rate at rest but often does not provide adequate rate control during exertion as it works mainly by increasing vagal tone. Digitalis is no longer recommended for rate control except in patients with heart failure because digitalis has been shown to increase the risk of all-cause mortality, particularly among patients with AF.

Radiofrequency catheter ablation of the AV node results in complete AV nodal block and substitutes a regular, paced rhythm for an irregular and rapid native rhythm. It is a useful strategy in patients who are symptomatic from AF because of a rapid ventricular rate that cannot be adequately controlled pharmacologically by medications and who either are not good candidates for AF ablation or have already undergoneunsuccessful attempts at ablation. AV node ablation also can be helpful in patients with heart failure and AF to maximize the benefits of cardiac resynchronization therapy (CRT) if there already is not 100% ventricular pacing. In patients with AF and an uncontrolled ventricular rate, AV node ablation improves the left ventricular ejection fraction (EF) if there is a tachycardia-induced cardiomyopathy. AV node ablation also has been shown to improve symptoms, quality of life, and functional capacity and to reduce the use of health care resources.67-69 The disadvantages of AV node ablation are that it creates a lifelong need for ventricular pacing and does not restore AV synchrony. Although symptoms and functional capacity typically improve after AV node ablation in patients with AF and an uncontrolled ventricular rate, some patients may not feel as well as during sinus rhythm. Atrioventricular node ablation is a technically simple procedure with an acute and long-term success rate of 98% or higher and a very low risk of complications. In patients with persistent AF, a ventricular pacemaker is implanted. A dual-chamber pacemaker is appropriate if the AF is paroxysmal. Most patients have a good clinical outcome with right ventricular pacing, but in patients with left ventricular dysfunction, biventricular pacing for CRT is appropriate.

2.

Elsevier ClinicalKey Clinical Overview

Treatment Attempts at cardioversion to attain sinus rhythm is best for individuals who have recent-onset atrial fibrillation Cardioversion can be electrical or pharmacologic When considering cardioversion, determine whether there is a specific trigger for atrial fibrillation that can be assuaged (eg, pneumonia, alcohol abuse, acute mitral regurgitation, thyroid storm) and evaluate whether trigger can be remedied Attempts at cardioversion may fail in such situations Restoration of sinus rhythm may need to be postponed until after trigger can be controlled (eg, improvement in oxygenation in a hypoxemic patient with pneumonia) In a patient with acute exacerbation of congestive heart failure, some compensation of heart failure must be achieved Ongoing management pathways vary according to type of atrial fibrillation (paroxysmal, persistent, or permanent), presence or absence of continued symptoms with initial rate control, and presence of underlying conditions (structural heart disease, coronary artery disease, or heart failure) ( Figures 3 - 6 ) Specifics of rate control management In patients with rapid ventricular rates, acute rate control is best achieved by IV atrioventricular nodal blockade in patients who do not have accessory pathway conduction ( Table 1 ) Either an IV β-blocker or a nondihydropyridine calcium channel blocker is recommended. β-blocker is preferred in patients with atrial fibrillation accompanied by systolic dysfunction Diltiazem is frequently administered and titrated for initial rate control owing to ease of titration and possibly less frequent hypotension IV metoprolol makes the most sense in patients with ischemic heart disease and those who have had cardiac surgery To avoid rebound tachycardia as the IV dose wears off, administer with an oral rate-control agent Oral atrioventricular nodal blockers, which have a longer duration of action, can also be considered as the initial drug formulation in hemodynamically stable patients and then continued for chronic rate control

3.

Food and Drug Administration (DailyMed).

Publish date: December 5, 2021.

Indications And Usage 1 INDICATIONS AND USAGE Esmolol Hydrochloride in Water (esmolol hydrochloride) is a beta-adrenergic blocker indicated for the short-term treatment of: • Control of ventricular rate in supraventricular tachycardia including atrial fibrillation and atrial flutter and control of heart rate in noncompensatory sinus tachycardia (1.1) • Control of perioperative tachycardia and hypertension (1.2) 1.1 Supraventricular Tachycardia or Noncompensatory Sinus Tachycardia Esmolol Hydrochloride in Water (esmolol hydrochloride) is indicated for the rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter in perioperative, postoperative, or other emergent circumstances where short term control of ventricular rate with a short-acting agent is desirable. Esmolol Hydrochloride in Water (esmolol hydrochloride) is also indicated in noncompensatory sinus tachycardia where, in the physician’s judgment, the rapid heart rate requires specific intervention. Esmolol Hydrochloride in Water (esmolol hydrochloride) is intended for short-term use.

Clinical Studies 14 CLINICAL STUDIES Supraventricular Tachycardia In two multicenter, randomized, double-blind, controlled comparisons of Esmolol Hydrochloride in Water (esmolol hydrochloride) with placebo and propranolol, maintenance doses of 50 to 300 mcg/kg/min of Esmolol Hydrochloride in Water (esmolol hydrochloride) were found to be more effective than placebo and about as effective as propranolol, 3 to 6 mg given by bolus injections, in the treatment of supraventricular tachycardia, principally atrial fibrillation and atrial flutter. The majority of these patients developed their arrhythmias postoperatively. About 60 to 70% of the patients treated with Esmolol Hydrochloride in Water (esmolol hydrochloride) developed either a 20% reduction in heart rate, a decrease in heart rate to less than 100 bpm, or, rarely, conversion to normal sinus rhythm and about 95% of these patients did so at a dosage of 200 mcg/kg/min or less. The average effective dosage of Esmolol Hydrochloride in Water (esmolol hydrochloride) was approximately 100 mcg/kg/min in the two studies. Other multicenter baseline-controlled studies gave similar results.