MercyOne Iowa Heart Center cardiologists perform 500 WATCHMAN procedure

April 27, 2022

Electrophysiologists at MercyOne Iowa Heart Center, performed their 500 WATCHMAN Left Atrial Appendage Closure Implant procedure today. This implant is a treatment for patients who have non-valvular atrial fibrillation.

Atrial fibrillation (AF) is a heart condition where the upper chambers of the heart (atrium) beat too fast and with irregular rhythm (fibrillation). Twenty percent of all strokes occur in patients with AF, and AF-related strokes are more frequently fatal and disabling.

 “It is an incredible accomplishment for our team to reach this milestone,” Troy Hounsehll, DO, MercyOne Iowa Heart Center electrophysiologist and medical director of research said. “Our team has worked diligently to become leaders in this life-saving technology, implementing both the WATCHMAN and WATCHMAN FLX devices and being part of early research trials bringing them market.”

People with atrial fibrillation have a five times greater risk of stroke. Atrial fibrillation can cause blood to pool and form clots in the left atrial appendage (LAA). For patients with non-valvular AF, the LAA is believed to be the source of the majority of stroke-causing blood clots. If a clot forms in the LAA, it can increase one’s risk of having a stroke. Blood clots can break loose and travel in the blood stream to the brain, lungs, and other parts of the body.

For patients with AF who are at risk for stroke but are unsuitable for blood thinners, the WATCHMAN implant is an alternative to reduce their risk of AF-related stroke. It closes off the LAA to keep harmful blood clots from forming in it and potentially causing a stroke. By closing off the LAA, the risk of stroke is reduced and, over time, patients stop taking blood-thinning medication.   

Implanting the WATCHMAN device is a one-time procedure that usually takes about an hour to complete. Following the procedure, patients typically need to stay in the hospital for 24 hours.

“We are the top implanter in the state and are a leader regionally and nationally for our quality outcomes,” said Dr. Hounshell. “We continue to pioneer this therapy to eliminate the need for lifelong blood thinners for our patients.”

For more information on MercyOne Iowa Heart Center and the WATCHMAN device, visit

About Iowa Heart Center

MercyOne Iowa Heart Center, founded in 1970 and a member of MercyOne, is one of the nation’s premier cardiovascular medicine practices. With clinics and offices in Des Moines, Ames, Ankeny, Carroll, Fort Dodge, Marshalltown, Newton, and Ottumwa, MercyOne Iowa Heart Center’s physicians and staff are committed to providing world-class heart care, research and prevention services to Iowa families.

About MercyOne

MERCYONE is a connected system of health care facilities and services dedicated to helping people and communities live their best life. MercyOne’s care providers and staff make health the highest priority. The system’s clinics, medical centers, hospitals and affiliates are located throughout the state of Iowa and beyond. Headquartered in central Iowa, MercyOne was founded in 1998 through a collaboration between CommonSpirit Health and Trinity Health – two of the country’s foremost, not-for-profit Catholic health organizations.