When You Have AFib and High Blood Pressure

If you have atrial fibrillation (AFib), there's a pretty good chance you have high blood pressure, too. The two conditions often go together.

When everything's going right, your heart chugs along with a steady rhythm you can keep time to. It pumps blood through your body with just the right touch, and all your cells get the oxygen they need.

But high blood pressure throws a wrench into those works. It means your blood's flowing with more force than normal, so it's pushing hard on your artery walls. If that goes on for too long, the added stress causes damage that can lead to all kinds of problems.

One of them is AFib, where your heart's regular rhythm gets thrown off. The two chambers in the top part of your heart -- the atria -- quiver instead of pump, so your heart doesn't work as well to push blood out to your body.

While AFib has several possible causes, high blood pressure tops the list. Your odds of having both conditions go up as you get older.

These two share another connection, too. They both raise your chances of having a stroke.

How High Blood Pressure Leads to AFib

If you don't get treatment for high blood pressure -- or if it's not treated well -- there are a few ways it puts you at risk for AFib.

Healthy blood vessels are strong and flexible, but like everything else, they have their limits. If they constantly have too much pressure put on them, they start to wear down. And when pushed too far, they begin to narrow and cut blood flow. When that happens to blood vessels in your heart, it can affect your heart's rhythm.

Also, the higher pressure makes your heart work harder than normal. It's kind of like constantly flooring the gas pedal in your car. Short bursts are fine, but keep the pedal to the metal, and your engine wears down much more quickly. When your heart's always on overdrive, it starts to get thick and stiff.

That's a problem because your heart's rhythm is controlled by electrical signals. When your heart changes like that, those signals don't flow as well and your heart loses its regular rhythm, which can eventually lead to AFib.


AFib and Stroke

A lot of people -- even some who have it -- don't think AFib is too serious of a condition. And if it was just a matter of a faster heartbeat and the occasional weird feeling in your chest, they might be right.

But with AFib, you get a much higher chance of having a stroke, where you lose blood flow to part of your brain. AFib has a hand in about 1 in every 5 strokes.

That's because when atria quiver instead of pump, blood can start to pool in your heart. The longer that blood sits around, the more likely it is to form a clot, which can break away and travel throughout your body. If that clot gets stuck in an artery that supplies blood to your brain, it causes a stroke.

High Blood Pressure and Stroke

About 3 in 4 people who have a stroke also have high blood pressure. The reason is that when an artery gets damaged, it gets little cracks and crevices where plaque -- a fatty, waxy substance -- can build up.

As plaque collects, it narrows the artery, which lowers or even blocks blood flow. It's just like a clog in a pipe. If the clogged artery supplies the brain, it can cause a stroke.

The damage from high blood pressure can also create weak spots in arteries. That makes them more likely to burst, which causes a stroke if it happens in your brain.

Adding It All Up

Since more people have high blood pressure than AFib, high blood pressure plays a role in more strokes. That's just a straight numbers game.

But AFib poses the greater stroke risk: With high blood pressure, you're two times more likely to have a stroke. With AFib, you're five times more likely.

So, if you have high blood pressure, you're more likely to have AFib. And if you have both, you're hit with two of the leading causes of stoke, making your chance of having a life-threatening condition even higher.

That all means it's really important to keep your blood pressure in check. You'll have healthier blood vessels, keep AFib out of the picture, and lower your odds of having a stroke.

WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on July 17, 2019



Mayo Clinic: "High Blood Pressure (Hypertension)," "Atrial Fibrillation."

American Heart Association/American Stroke Association: "When the Beat is Off -- Atrial Fibrillation."

European Society of Hypertension: "Hypertension and atrial fibrillation: diagnostic approach, prevention and treatment. Position paper of the Working Group 'Hypertension Arrhythmias and Thrombosis' of the European Society of Hypertension."

American Heart Association: "High Blood Pressure, Afib and Your Risk of Stroke," "What is Atrial Fibrillation (AFib or AF)?"

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