It's a debilitating heart condition that can often be fixed with the right treatment.
Now, doctors are using new imaging technology to make that treatment more accurate and effective.
Like more than five million Americans, Carla Schindeler has a racing, irregular hearbeat called atrial fibrillation.
About 35-percent of people with it will have a stroke, but doctors like Ahmed Osman can destroy the heart tissue that causes the problem with a catheter procedure called ablation.
Dr. Osman is a cardiac electrophysiologist with Broward General Medical Center. He said, "What we are trying to achieve with ablation is hopefully isolate and silence the triggers for atrial fibrillation."
Doctors need precise imaging to get the best results during an ablation. Now, new technology helps them see the heart in real-time like never before.
"It has clearly and dramatically changed the way we manage the disease," Osman said.
By inserting a tiny probe in the vein, doctors get images in different planes and virtually reconstruct the left atrium. 3-D mappking then enhances how doctors view and treat the heart.
Dr. Osman said, "We are able to navigate very accurately inside the left atrium and achieve electrical isolation of the veins."
Carla was treated with help from the new imaging system and says she's never felt better. "I feel so much more comfortable now doing things, because you just don't live in fear that something's going to go amiss."
The risk of atrial fibrillation increases with age. Researchers expect the condition to affect nearly 16 million Americans by the year 2050.