Rate Control Medications
Once your stroke risk is addressed, you may live a perfectly normal life if you don't have symptoms of atrial fibrillation, such as shortness of breath, fatigue, and dizziness. But it’s not wise to go too long with a heart that’s beating too fast.
“If your heart rhythm is off but the rate isn’t too fast, that isn’t as much of a problem,” says Whang. “But when the heart rate is over 100 beats per minute for very long, the bottom pumping chamber -- the ventricle -- can become weak.” This leads to a condition called cardiomyopathy, which puts you at greater risk for heart failure.
The medications that slow down a racing heart are known as rate control medications. There are two types that are most commonly used:
- Calcium channel blockers
These drugs have been used in millions of people for many years to treat high blood pressure and coronary artery disease. “They’re very well understood, and very well tolerated,” says Whang.
Your doctor may also prescribe medications called anti-arrhythmics to address the irregularity of atrial fibrillation. Not everyone with AFib needs them. If you aren’t bothered by symptoms from your AFib, your doctor may decide that correcting the rhythm may not be worth the side effects of the various medications that are available.
But some people with AFib do struggle daily with fatigue, shortness of breath, and dizziness that may accompany the condition. In that case, doctors may recommend one of a number of medications. The one they choose for you will depend on a number of factors -- for example, certain anti-arrhythmic drugs are not suitable for people who also have other underlying heart disease.
The two main categories of drugs that are used specifically to control rhythm are:
- Sodium channel blockers, which decrease the speed of electrical conduction in the heart muscle. These include drugs like disopyramide, flecainide, and propafenone. “They can’t be used in patients with coronary disease or any kind of heart failure,” cautions Wylie.
- Potassium channel blockers, which slow nerve impulses in the heart. They include dofetilide and sotalol. “Because they affect the kidneys, they can’t be given to patients with renal dysfunction,” Wylie explains. Dofetilide also poses a risk of causing life-threatening ventricular arrhythmias, so it must be started in the hospital. That way, the patient can be carefully monitored during the first few days of therapy, when most of these complications happen.