Atrial fibrillation is often a chronic illness so it is important that patients understand what treatment options they have on offer. Patients generally have two strategies for treating atrial fibrillation:
Rate control through medical treatment of atrial fibrillation
The first method is called Rate Control. This involves accepting that the patient has atrial fibrillation, but taking medication to avoid a rapid conduction of fibrillation impulses from the atria to the heart chambers. This means that the medicine needs to prevent a patient’s pulse becoming too fast, whether at rest or undergoing activity.
The goal of the treatment is to keep the resting heart rate below 90 beats per minute, and the heart rate during moderate activity, such as walking up a flight of stairs or engaging in a brisk walk should not exceed 115 beats per minute.
If your doctor recommends Rate Control they will prescribe one of three medications. Beta-blockers (metoprolol succinate, selozok, atenolol etc.) calcium channel blockers (verapamil) or digoxin. Beta-blockers often have side effects such as fatigue, lowered physical capacity, weight gain, impotence, and restless dreams. Calcium blockers can cause constipation and swollen ankles or lower legs.
Rhythm Control through medical treatment of atrial fibrillation
The second strategy is called “rhythm control”. It aims to completely stop atrial fibrillation and prevent reoccurance. In other words, a strategy that aims to restore a normal heart rhythm, known as a sinus rhythm. .
If your doctor pursues a Rhythm Control strategy they may recommend beta blockers or calcium blockers but there are more effective treatments. The most common prescriptions will be for flecainide (Tambocor), propafenone (Rytmonorm), sotalol (=Sotacor), and amiodarone (Cordarone / Cordan).
Flecainide is often quite effective – both in stopping episodes of atrial fibrillation and in preventing new attacks. However it can only be used if the heart’s pumping function is normal and there are no signs of atherosclerosis. Side effects are modest but can include visual impairment or dizziness. Doctors will often combine flecainide with a smaller dose of beta-blockers or calcium-blockers to prevent the fast conduction of impulses from the atria to the heart chambers during and eventual atrial flutter. This works because supplemental medication inhibits the impulse connection from the atria to the ventricles.
Sotalol is not much more effective than beta blockers. Additionally, the drug carries the risk of arrhythmias from the heart chambers, which can be dangerous. This is especially common for people with impaired kidney function, women and for people who are also given other types of medication that can affect the so-called QT interval, which is measured on the ECG.
Multaq is, in my experience, not very effective, and has many side effects – often in the form of very annoying nausea. However if it works, and the side effects are not too burdensome, it can still be used
Amiodarone is the most effective drug to avoid atrial fibrillation. However, it also has many side effects – especially with long-term treatment lasting more than e.g. 6 months. The side effects range from a hypersensitivity to sunlight (you do not tolerate the sun well – burn faster) to metabolic effects and the risk of damage to the liver, lungs, and nervous system. It may be appropriate to use this drug for a short period before and after DC conversion ( a shock to the chest to stop atrial fibrillation) or for a period after ablation treatment. In addition, it is rarely used for more long-term treatment due to the many side effects.
Flecainide (Tambocor), propafenone (Rytmonorm), sotalol (Sotacor) and Multaq treatment should always be started while staying at the hospital, typically for at least two days. This enables doctors to monitor your heart rhythm. Cordarone treatment can begin without being monitored in a hospital environment.
Side effects of medical treatment of atrial fibrillation
A frequent side effect that I often hear about myself, especially during treatments that include beta-blockers, sotalol, and amiodarone, is increased fatigue and reduced physical abilities. This is because the medicine lowers the resting heart rate. This also means that the heart raises more slowly during physical activity than it would ordinarily. This means that it is too slow to increase the supply of oxygen to muscles and other organs, causing rapid fatigue. Therefore physicians should take care to prescribe the lowest dosage possible. Physicians should also avoid combining drugs with conduction slowing properties, such as combinations of beta-blockers and Cordan / Cordarone.
Doctors should take particular care when prescribing Cordan/Cordarone and Sotalol/Sotacor. Other medicines, some quite common, can amplify the effects of these drugs on the electrical relaxation of the heart muscle cells between each heart beat. This means a risk of prolongation of the so-called “QT-interval” giving rise to “long-QT”. This can put patients at risk for potentially life-threatening heart rhythm disturbances and so it is important that both the doctor and patient are aware of any current prescriptions, even if they seem innocuous.