Atrial fibrillation Treatment Part 1
I discussed causes and symptoms of Atrial Fibrillation (AF) in this column in November 2022; for the next three weeks, I discuss AF treatment.
Aims of AF management are to:
- Relieve symptoms, such as palpitations, tiredness, dizziness, and breathlessness
- Prevent serious complications, such as stroke and CHF
- Regulate heart rate
- Treat the cause of AF where identifiable
Medication used to slow the heart rate include:
- Beta-blockers (atenolol, metoprolol)
- Dihydropyridine calcium channel blockers (CCBs) (e.g.) verapamil, diltiazem
- Amiodarone (less often used due to risk of side effects)
Beta blockers such as atenolol and metoprolol are used to control ventricular rate in AF.
Dihydropyridine calcium channel blockers (CCBs) such as diltiazem or verapamil as monotherapy are an option for ventricular rate control in AF. Dihydropyridine CCBs have the effect relaxing and widening blood vessels as well as the additional effects of being rate limiting meaning they decrease myocardial contractility and heart rate.
The choice of use of beta blockers versus dihydropyridine CCBs is based on type of symptoms, heart rate and the presence of other conditions.
Studies indicate digoxin is less effective than CCBs and amiodarone at controlling heart rate acutely (i.e.) need for fast rate control. Digoxin is more effective at controlling ventricular rate when the patients are at rest so is reserved as monotherapy for AF patients with a sedentary lifestyle and for non-paroxysmal AF, especially those with left ventricular systolic dysfunction. Digoxin is used when beta-blockers do not give sufficient rate control and where beta blockers are poorly tolerated and/or contraindicated.
A single drug may not be sufficient to control ventricular rate so a combination of two drugs such as a beta-blocker, digoxin, or diltiazem is the next option. When ventricular function is reduced, the combination of a beta-blocker and digoxin is preferred option.
Covid-19 Booster Vaccine
If you have atrial fibrillation, you may be at more risk from COVID-19. Whelehans Pharmacy Pearse St have a weekly walk-in clinic every Wednesday afternoon for Covid-19 booster. Call 0449334591 for more info or register on the Whelehans Website.
To be continued…next week