Atrial Fibrillation After Heart Surgery

From the authors of The Cardiac Surgery Playbook: Daniel T. Engelman, MD, Cheryl Crisafi, MSN, RN, and Armando Paez, MD

Atrial fibrillation, often shortened to AFib, is the single most common complication after heart surgery. It affects about a third of people after bypass surgery and is more common after valve operations. Hearing that your heart is "out of rhythm" can be alarming. In most cases it is temporary and treatable. Here is what to expect.

What atrial fibrillation is

In a normal rhythm, the heart's upper chambers beat in a steady, organized way. In atrial fibrillation they quiver and fire in a fast, disorganized pattern. The heartbeat becomes irregular and often rapid.

AFib matters in two different settings around heart surgery. Some people already have it before the operation. Many others develop it for the first time in the days after surgery. This page covers both.

New AFib in the days after surgery

New AFib happens because the heart is swollen, irritated, and under stress right after the operation. It usually appears in the first few days, often around the second to fourth day. It often causes a fluttering or racing feeling in the chest. Some people feel nothing at all, and the monitor picks it up first.

AFib after surgery is usually temporary. Most people are back in a normal rhythm by the time they go home, or soon after.

How the team treats it

Your team treats new AFib in a few ways:

• Medicines such as beta blockers or amiodarone to slow and steady the rhythm
• Correcting things that provoke it, such as low potassium or magnesium
• If it persists, a brief, controlled electrical shock under sedation, called a cardioversion, to reset the rhythm

Why a blood thinner may be added

Because AFib raises the risk of stroke, your team may start a blood thinner. This is most likely if the AFib persists or keeps coming back, and it also depends on your overall stroke risk.

If you go home on a rhythm medicine or a blood thinner for this reason, your team will tell you how long you are likely to need it. Do not stop either one on your own when your heart feels normal again. AFib can come and go silently, and stopping these medicines without guidance raises your stroke risk.

If AFib starts after you go home

AFib is one of the most common reasons people return to the hospital in the weeks after heart surgery. A short readmission to control the rhythm is not a failure. It is sometimes the safest way to treat it properly.

If you feel a racing, fluttering, or irregular heartbeat after you go home, call your surgical team the same day. Do not wait for your next appointment. A smartwatch alert about an irregular rhythm is a prompt to call, not a diagnosis.

Seek emergency care right away if the irregular heartbeat comes with fainting, dizziness, chest pain, or severe shortness of breath. Also seek emergency care for any sign of stroke: sudden weakness or numbness on one side, facial drooping, trouble speaking, or loss of vision.

If you already have AFib before surgery

If you are known to have AFib, discuss it with your surgeon. Some treatments can be done during your heart operation, sparing you a separate procedure. Two are worth asking about.

The first is a surgical ablation, often called a Maze procedure. The surgeon creates a precise pattern of scar lines in the upper chambers, using radiofrequency energy or extreme cold. Scar tissue does not carry electrical signals, so the lines block the chaotic impulses. AFib that comes and goes is cured more often than AFib that has been continuous for years.

The second deals with the left atrial appendage. This small pouch off the left upper chamber is where most AFib-related clots form. During surgery it can be closed with a small permanent clip, stitches, or a stapler, or removed. Closing it lowers the long-term risk of stroke.

Lowering your own risk

Taking your beta blocker as prescribed before and after surgery reduces the chance of AFib. So does keeping your potassium and magnesium in range, which your team checks with blood tests. Heavy drinking before surgery raises the risk of an irregular rhythm, so be honest with your team about alcohol.

Learn more in The Cardiac Surgery Playbook

Chapter 7, Atrial Fibrillation and Heart Rhythm, explains the Maze procedure, the appendage clip, and the questions to ask. Chapter 21, When Things Do Not Go as Planned, covers AFib alongside the other common complications and how each one is handled.

Go deeper in the book. Chapter 7: Atrial Fibrillation and Heart Rhythm; Chapter 21: When Things Do Not Go as Planned. Written by a cardiac surgeon, a cardiac surgery nurse and an infectious disease physician, with worksheets you can fill in for your own care.

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This page is general education, not medical advice. Your own surgeon and care team know your situation best. If you think you are having a medical emergency, call 911.

More questions before heart surgery