How Can I Manage Atrial Fibrillation?
With the morbidity and mortality associated with atrial fibrillation (AF), it is prudent to identify it quickly and treat it to prevent life-threatening impairment of cardiac output, stroke, cognitive changes, and cardiac death. Those with additional cardiac disease, e.g., coronary artery disease, heart failure, and hypertension, have augmented risks. In any management of AF, reversible triggers should be eliminated, such as hyperthyroidism and hyperglycemia. If a patient is hemodynamically unstable, management by an intensivist in a cardiac care facility is necessary, including immediate cardioversion and anticoagulation. A patient is considered unstable if there is sever bradycardia (slow rate) or prolonged pauses or intervals during each cycle. For those who are hemodynamically stable, restoring a normal sinus rhythm is done via a more methodical course of cardioversion.
Cardioversion treatment involves restoring a normal sinus rhythm. There are two ways to accomplish cardioversion:
- Chemical (oral beta blockers or ACE inhibitors).
- Electrical (DC shock).
The electrical cardioversion has a better success rate than the chemical approach, but the decision of which to use is individualized based on patient condition, comorbidities, age, patient preference after informed consent, and physician judgment. One factor that is considered is that antiarrhythmic drugs themselves can cause arrhythmias. Alternately, oral medication does not involve sedation and anesthesia which may be contraindicated in some individuals. Antiarrhythmic drugs are used after cardioversion to maintain the gains that electrical stimulation creates by reestablishing a normal sinus rhythm.
New-Onset Atrial Fibrillation
A person with his or her first episode of AF should undergo cardioversion, since there are some AF patients who will never have a second episode. AF is a condition that affects both cardiac rate and rhythm, and of these, rate control is the first step (unless the patient is unstable). Beta blockers or ACE inhibitors are used until there is a rate of 90 or less. After the rate is controlled, attention to the rhythm is next, via cardioversion.
Longstanding or Recurrent Atrial Fibrillation
There are two goals for patients with AF:
- Symptom control
- Prevention of thromboembolism
Rate control (generally for those >65 years of age) is achieved with blockage of the propagation of the rapid atrial impulses at the next stage of cardiac conduction to the ventricles at the atrioventricular (AV) node. Medications used include rate-slowing calcium-channel blockers, beta blockers, or digoxin. Rhythm control (generally for those <65 years of age) is achieved using antiarrhythmic drugs. This choice is primarily centered on relieving the symptoms that AF produces.
With the increased risk of thromboembolism (and its tendencies toward stroke and death), atrial fibrillation’s association with thrombus formation is countered with an anticoagulation strategy.