Written on behalf of the Sanger Heart and Vascular Education Group
A 73-year-old male patient with a known ischemic cardiomyopathy and ejection fraction of 30% has been having heart palpitations for about a month before scheduling an appointment with his primary cardiologist. At his visit, his electrocardiogram reveals new-onset atrial fibrillation (AF).
When thinking about the appropriate use of antiarrhythmics in this case, which of the following is true?
The correct answer is: C. Amiodarone's half-life is 53 days.
It is true that amiodarone's half-life is 53 days.
Regarding answer A, flecainide is a Class 1c antiarrhythmic; propafenone is also in this class. These medications are not good choices in patients with AF who have structural heart disease (e.g., low ejection fraction, significant left ventricular hypertrophy, or coronary artery disease).
Regarding answer B, dronedarone is a Class 3 antiarrhythmic. Amiodarone falls into the same class of antiarrhythmics. Dronedarone was thought to be a better long-term alternative as an antiarrhythmic versus amiodarone initially, however, it was found that increased cardiovascular death occurred in patients who had known history of permanent AF or a recent hospitalization for decompensated heart failure.
Regarding answer D, procainamide, a Class 1a antiarrhythmic, is known to cause a lupus-like syndrome in some patients.
Regarding answer E, IV procainamide can be an effective strategy to terminate AF if duration <48 hours. It can be given as a 1-gram dose IV and infused slowly over 1 hour. Prolonged QTc and hypotension can occur. Continuous monitoring is essential.