Electrical shock normalizes heart rhythm for those with AFib

DEAR DR. ROACH: I was diagnosed with atrial fibrillation in January 2012. I am aware of when it comes by how I feel -- a little out of sorts, but no shortness of breath, chest pain or light-headedness. Consulting with my app on my smart watch confirms the same. I am taking bisoprolol and rivaroxaban. Occasionally, I get an episode, which lasts anywhere from 1 to 4 hours. It subsides, and I’m over it. But last time, it lasted nearly 12 hours before it subsided and went away.

At the time of diagnosis, the cardiologist suggested that should an episode persist, I need to get to an emergency room and undergo a mild shock treatment to correct my heart’s beating. My question is this: How long do I wait? -- R.B.

ANSWER: Atrial fibrillation, an electrical abnormality of the heart causing an irregular heartbeat, can persist, or it can come and go. There are two goals when treating AFib: treating symptoms and preventing stroke. Both of these are usually done with medication when necessary, but it may also be done with electricity, giving a shock to the heart to “reset” the electrical system.

Emergency treatment with a shock (“cardioversion”) is indicated when a person is unstable, such as a person with very low blood pressure, causing the brain or heart to lack enough blood flow. That’s not you. People can have AFib for decades, but no additional treatment may be necessary as long as their heart rate is under control (bisoprolol, a beta blocker, is good at keeping the heart rate from going too fast) and they are doing what they should to prevent stroke (rivaroxaban, a direct-acting oral coagulant, reduces stroke risk).

Sometimes, a person with AFib undergoes cardioversion in an attempt to return their heart to its normal rhythm. This is usually done in a person to keep them at a normal rhythm permanently. However, there are some cardiologists who recommend what yours has, to use electricity in case you don’t go back into normal rhythm spontaneously, although this is not a commonly used strategy in my experience.

Other cardiologists use medications (either the “pill in a pocket” approach for a person to use by themselves, or in the ER under observation). In one study I read, participants were instructed to go to the ER if their symptoms hadn’t gotten better in six to eight hours, but you should certainly get an answer from your cardiologist.

One major concern in giving an electrical shock to a person with AFib is that if a clot has formed in the heart, going into a normal rhythm can precipitate the clot going up to the brain and causing a stroke. This isn’t an issue in people who have just started experiencing atrial fibrillation or in those who have been on anticoagulation for at least a few weeks; otherwise, anticoagulation with rivaroxaban or another similar medicine is done to prevent stroke prior to electrocardioversion.

This is an area in which great skill and clinical experience is needed, and I refer my patients to an electrophysiologist, a cardiologist with expertise in electrical problems of the heart.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.