Rate Control vs. Rhythm Control in Treating Atrial Fibrillation
When you or someone you care about is diagnosed with atrial fibrillation it's important to know what your doctor's main goals are in treating this common cardiac arrhythmia.
Your doctor will be most concerned about preventing any kind of circulatory instability that may result from the irregular beat and to avoid the higher risk of stroke that goes along with it.
How will he or she achieve this? Heart rate, rhythm, and anti-coagulation are the three main cornerstones of afib treatment.
One of the most basic decisions will involve rate vs. rhythm control. It is an ongoing debate in the treatment of the condition and is often dependent on the individual patient.
Afib can cause symptoms that are annoying, frightening, and disabling. They include chest pressure, palpitations, chest pain, lightheadedness, fainting, and general malaise. The symptoms vary not only from patient to patient, but also from one day to the next.
It is not surprising that all of these symptoms can cause anxiety. Decreased exercise tolerance can slow down a formerly active adult and keep her from doing many of the things she used to enjoy. Some people experience a persistent rapid heart rate, which can cause a form of heart failure called "tachycardia induced cardiomyopathy." This condition significantly increases morbidity and mortality. So, it is important to treat early and adequately.
Doctors can approach symptoms of afib by using drugs to control rate, rhythm, or both.
Rate control will slow down the heart rate to somewhere between 60-100 beats per minute, without trying to control rhythm. This course of treatment was my decision (and my doctors went along with it) when I was first diagnosed with afib. I did not want to take rhythm control medications (known as anti-arrhythmics) because of the possible side effects of these drugs, which can be significant. So, in the beginning of my afib experience, and for the three months before I underwent a cardioversion, I was prescribed a beta blocker (actually, I had been on Propranolol for many years), Digoxin , and, of course, I was put on the anticoagulant Warfarin.
This managed my afib symptoms pretty well. I was not really aware of my heart beating irregularly, although I did notice that I would become out of breath more quickly than usual. I had regular weekly blood checks because my doctor wanted me to be in INR (international normal ratio) with my blood thinner for at least 6-8 weeks before he would do a cardioversion.
Rhythm control is often preferred by younger, active patients who want their heart rate to get back to normal. Anti-arrhythmic drugs do this either via a chemical cardioversion, or the patient is given a cardioversion and then put on the anti-arrhythmic medications to maintain it. However, medications, and even surgical ablation treatments, may not always be successful.
What is the difference between rate control treatments or rhythm control methods? According to a five year study called AFFIRM trials, there appears to be a lower mortality rate using rate control with anti-coagulation treatment (blood thinners) and the difference between rate and rhythm increases up to five years (when the study ends).