May is stroke awareness month and one of the common causes of stroke is an abnormal heart beat, which can lead to a deadly blood clot. There's now a device available that can help prevent strokes. NY1's Erin Billups filed the following report.

Margaret Cienki is one of at least three million Americans with atrial fibrillation, an abnormal heart beat.

"As the top chamber is not beating properly. Blood is not flowing, moving quite normally. There's a blind pouch in the top chamber called the left atrial appendage. This appendage is an area where blood can swirl and basically clot," explains Dr. Vivek Reddy, Cardiac-Electrophysiology Director at Mount Sinai Hospital.

That clot could then prevent blood from reaching her brain - potentially leading to the most dangerous consequence, a stroke. She's already at higher risk because she's 80 years old.

First, her doctor prescribed the blood thinner Coumadin, also known as Warfin, to prevent clotting.

"With the falling - it's not a good combination. The blood thinners," said Cienki's son, Michael Cienki.

And Cienki did fall, causing internal bleeding. The drugs prevented her body from quickly stemming the flow. So her doctors at Mount Sinai Hospital decided to insert a new device, called the Watchman, into her heart to plug up the problem chamber.

"You can think of it like an umbrella that sits at the mouth of the appendage and sort of closes off that blind pouch. So that any clot that's inside can't travel through the blood circulation go to the brain and cause a stroke," says Dr. Reddy.

Reddy was the lead investigator in the clinical trials for the Watchman. Cienki was the first person to receive it in the eastern U.S. after it won FDA approval.

"We were glad there was another alternative. If there wasn't that she would just have to be on blood thinners," said Michael Cienki.

Six weeks after Cienki received the device, she was taken off the drugs and her fear of bleeding is fading.

"Oh a big difference, there's more confidence in me, that I'm able to do things," says Margaret Cienki.

Reddy says, for some, blood thinners work well but he says the device may be better for the elderly.

"Because they're also the ones that have the greatest risk for bleeding," adds Dr. Reddy.

Studies show the device works as well as Coumadin at preventing stroke and there's less bleeding associated with it.