Atrial Fibrillation (A-fib): Rhythm Control or Rate Control?
A key decision intended to keep your heart in its usual, so-called sinus rhythm
Choosing rhythm control or rate control is one of two key decisions (the other is which blood-thinning medication to use to reduce the chance of A-fib-related stroke) that you and your doctor will make to manage atrial fibrillation. As with any important medical decision, start by understanding the options, along with their pros and cons. Here are the key things to know about these two options:
What it is: Doctors try to keep the heart in its usual electrical rhythm, known as "sinus" rhythm. The process of switching the heart from atrial fibrillation to sinus rhythm is called "cardioversion." This is most commonly done either by applying a controlled electric shock to the heart or by using medication. Indefinite use of "antiarrhythmic" medication is often needed to keep the heart in sinus rhythm. In a minority of cases, permanent rhythm control is attempted using radiofrequency catheter ablation or even open-heart surgery.
Medications commonly used: amiodarone, flecainide, sotalol, propafenone, dronedarone
Pros: Many people (but not all) experience better heart function and fewer symptoms if they're able to maintain sinus rhythm.
Cons: Rhythm control often is hard to maintain long-term, especially in older adults. In fact, 35 to 60 percent of people end up back in intermittent or persistent A-fib, even if they continue to take antiarrhythmic medications as directed. Also, the medications themselves can cause serious side effects, especially with longtime use, and are prone to interact with other medications. In addition, these medications must usually be managed by a cardiologist rather than a primary care doctor.
How to tell if it's working: The person's pulse should feel regular when felt at the wrist or neck, or it should sound regular when the doctor listens with a stethoscope. An ECG will show sinus beats in the atria, rather than fibrillation. If there are concerns about occasional atrial fibrillation, a Holter monitor can be used to monitor the heart's electrical activity over 24 to 48 hours.
Tip to remember: Even successful rhythm control does not reduce the chance of A-fib-related stroke, so it's often still necessary to take blood-thinning medication.
What it is: Doctors leave the upper chambers (the atria) of the heart in fibrillation and use medications to keep the more powerful lower chambers of the heart (the ventricles) from beating too quickly. The goal for heart rate depends on the circumstances; usually doctors aim for a resting heart rate of 90 or less. In a minority of cases, the connection between the atria and the ventricles is permanently removed and a pacemaker is inserted to keep the ventricles beating regularly.
Medications commonly used: atenolol, metoprolol, verapamil, diltiazem
Note: These are also commonly used for treatment of high blood pressure.
Pros: Rate control is often easier to maintain than rhythm control, especially in older adults. Many people are able to achieve good symptom control when their heart rate is controlled, even though they're still in A-fib. The medications commonly used are familiar to primary care doctors and require fewer precautions and monitoring than antiarrhythmic medications.
Cons: Some people continue to experience A-fib symptoms, such as shortness of breath with exertion, despite successful rate control.
How to tell if it's working: The pulse will feel or sound irregular (with variable spacing between beats), but when beats are counted over a full minute, the rate at rest should be less than 90 or so. (Be sure to ask the doctor what the goal is for your particular circumstances.)
Tip to remember: Successful rate control doesn't reduce the chance of A-fib-related stroke, so it's often still necessary to take blood-thinning medication.
The bottom line
Rate control is simpler to implement and easier to maintain, especially in older adults. Most people have minimal symptoms from A-fib if their heart rate remains successfully controlled, but some require rhythm control to successfully reduce their A-fib symptoms.
In terms of long-term health results, most research has found that, overall, people do equally well regardless of whether rate control or rhythm control is used.