Heart rate control is a key way to manage atrial fibrillation. Doctors consider it one of the four pillars of AFib care, along with heart rhythm control, stroke prevention, and a healthy lifestyle. The goal is to keep your heart working consistently and smoothly over the years ahead.
What Is Rate Control for Atrial Fibrillation?
Rate control is not a cure for AFib, but a way of keeping your heart rate in check. It’s done with medications that keep your heart from beating too quickly. You take most of them on a regular basis. You use others when you’re having sudden problems.
The aim of these treatments is to slow down the rate of your heartbeat. This can reduce AFib symptoms and lead to a better quality of life. They also can improve hemodynamics, which is how well your heart and blood vessels move blood through your body.
How low your heart rate should go depends on how serious your condition is. If you’re having symptoms of AFib, your doctor will probably try to get your resting heart rate below 80 beats per minute. If you don’t have symptoms and your left ventricle (your heart’s main blood-pumping chamber) is working well, the goal may be a bit higher.
Without treatment for AFib, your heart rate might reach 150 beats per minute or more.
Why Is Rate Control a Goal in AFib?
When you have AFib, your heart doesn’t pump blood with each beat as well as it should. If your heart beats too quickly, your ventricle is even worse at sending blood where it needs to go.
This, along with rhythm problems, can make your AFib symptoms worse. It also can lead to heart failure or make existing heart failure worse. If your heart rate stays too fast for a long time, it can cause chronic disease of the heart muscle (tachycardia-induced cardiomyopathy).
How Is It Different From Rhythm Control?
Rate control and rhythm control are different things. Rhythm control involves the patterns – the regularity – of your heartbeat, rather than its speed.
Scientists don’t agree on which approach is better. But drugs for rate control are usually safer and tend to help treat heart disease more broadly. Some studies have shown when you get rate control treatments along with anticoagulant drugs (blood thinners) to prevent blood clots and stroke, they work just as well as rhythm control.
What Treatments Are Used for Rate Control?
Several rate control drugs are available. All work by blocking electrical signals in your heart’s atria, the chambers that receive blood from your circulatory system. That keeps these signals from reaching your ventricle.
Your doctor will decide which one to prescribe based on:
- How serious your symptoms are
- How well your heart is pumping blood (hemodynamic status)
- Whether you have heart failure
- The cause of your AFib
Your doctor will also consider any other conditions you might have, such as heart valve disease, left ventricular dysfunction, or pre-excitation (an electrical disorder of the heart).
The three main types are:
- Beta-blockers, such as atenolol (Tenormin), carvedilol (Coreg), metoprolol (Toprol XL, Lopressor), and sotalol (Betapace). These slow your heart rate and relax your blood vessels.
- Calcium channel blockers, such as diltiazem (Cardizem, Tiazac) and verapamil (Calan, Covera-HS, Isoptin). These also relax your blood vessels, plus they reduce how hard your heart works overall.
- Cardiac glycosides, such as digoxin (Lanoxin). These improve how well your heart can pump blood (called cardiac output).
All these drugs tend to be less risky than those used to achieve rhythm control. But they do have some potential side effects, like fatigue, shortness of breath, and dizziness. Some can even cause other rhythm problems. And cardiac glycosides can be toxic if you take too much.
Most often, your doctor will start with beta-blockers. Less common choices are calcium channel blockers and digoxin. If these drugs don’t work, or you can’t take them for some reason, your doctor might prescribe amiodarone (Cordarone, Pacerone).
Your doctor will make sure you’re on the right dose by using different tools:
- Electrocardiography, also known as ECG or EKG
- Ambulatory rhythm monitoring, such as telemetry or a Holter monitor, which checks your heart rate over time
- Exercise testing, which measures how well your heart works under exertion (stress)
If you need quick rate control during an AFib episode, your doctor might use IV medications to slow your heartbeat.
They can also do electrical cardioversion, a procedure that uses a high-energy electric shock to reset your heart rate. (It’s usually scheduled in advance and isn’t the same as the defibrillation used in emergencies.)
You might get electrical cardioversion if you’re not getting enough oxygen to your heart muscle, have low blood pressure, or are having decompensated heart failure (meaning the symptoms are serious enough to need treatment right away).
