Tiniest Monitor Helps Stroke Patients


AUSTIN, Texas – (July 15, 2015) – Prairie Lea special education teacher Mary Zion remembers her stroke like it was yesterday – even though it took months to learn what caused it.

But thanks to the world’s smallest heart monitor – it’s about the size of a matchstick – and the Seton Heart Institute, she did find out.


Zion was volunteering at a high school football game and experienced the classic symptoms of a stroke: fatigue, muscle weakness on one side of her body and slurred speech. A fellow volunteer called 911 and first responders called STAR Flight to take her to University Medical Center Brackenridge.

Doctors later told Mary she suffered from a “cryptogenic” stroke, a type of stroke where there is no known cause.

As part of Seton Healthcare Family’s ongoing commitment to cardiac and stroke care, interventional neurologist Dr. Jefferson Miley and cardiac electrophysiologist Dr. Mauricio Hong implanted the world’s smallest, insertable cardiac monitor into Zion’s chest to detect irregular heartbeats, also known as atrial fibrillation.

People such as Mary who suffer from cryptogenic strokes frequently suffer from an undiagnosed irregular heartbeat, a common cardiac condition. Irregular heartbeats put someone like Mary at risk for a recurrent stroke.

“Irregular heartbeats may occasionally have no symptoms when these heart rhythm disturbances sometimes occur,” said Hong, who cares for patients at the Seton Heart Institute. “Oftentimes, it can’t be detected by monitors commonly used in hospitals – but it can be detected by this new, implanted device.”

That is why Hong surgically implanted the Reveal LINQTM Insertable Cardiac Monitor (ICM) after Zion suffered her stroke. It automatically and continuously detects and records abnormal heart rhythms for up to three years. This allows physicians to more easily detect irregular heartbeats and change patients’ medical therapy according to guidelines to help reduce their risk of a second stroke.

After two months of monitoring, doctors determined Zion suffers from irregular heartbeats and she is now on medication to reduce her chances of suffering another stroke.

“These monitors are extremely important for those patients who suffer strokes from no known cause,” said Miley, an interventional neurologist with Seton Brain and Spine Institute. “We know that patients who suffer from this and aren’t treated are five times more likely to have another stroke.”

The Reveal LINQ ICM was approved by the U.S. Food and Drug Administration (FDA) last year. See how the LINQ device works.

Stroke Facts (from American Stroke Association)

  • According to the American Heart Association, approximately 795,000 Americans experience a new or recurrent stroke
  • An ischemic stroke, the most common type, is caused by a blockage or clot that forms in a blood vessel and obstructs blood flow to the brain
  • Of the nearly 690,000 Americans who suffer an ischemic stroke, the root cause of 20 to 40 percent of these stroke cannot be determined