In a Heartbeat

Tiny propeller keeps blood flowing

Heart
The percutaneous heart pump (PHP) developed at Penn State, shown here with a model of the left ventricle of a human heart, can keep a patient's blood flowing smoothly after a heart attack. Image: Courtesy of Rob Kunz

In the moments after a heart attack, every second counts. Medical professionals need to act quickly to stabilize the patient and prevent further damage to the heart. Often, that means opening up the chest cavity—a complex and traumatic procedure—and implanting a left ventricular assist device (LVAD) to help the weakened heart muscle keep pumping blood throughout the body.

Thanks to a new type of LVAD developed by Penn State researchers, such an invasive procedure might not be necessary for some heart patients. The tiny Heartmate PHP (percutaneous heart pump) is inserted into the femoral artery in the thigh and threaded up through the body into the left ventricle, where it keeps the blood flowing and thereby allows the heart to begin to heal right away. Recently approved for use in Europe, the device is currently undergoing trials for FDA approval in the United States. Once certified for use here, the pump has the potential to prolong the lives of tens of thousands of people each year.

“This is the first device that allows a cardiologist or technician to immediately stabilize someone who has had a serious heart attack,” saysRobert Kunz, principal investigator for the project. “Up until now, there was no question that if the patient’s heart stopped, the surgeon was cracking open the chest and going in. This pump is designed to be inserted, deployed, and operating within minutes of a patient suffering a heart attack. It buys some time, several days up to a couple of weeks, for the doctor to assess the situation—to say ‘We’re good for now’ while determining next steps.”

Kunz is not a surgeon himself. He’s an aerospace engineer, which at first blush may seem like an improbable match with biomedical research. But in fact, the six-millimeter-wide blood pump is essentially a miniature propeller, and Kunz and his research team applied the same suite of strategies and tools to developing the pump that they use for designing submarine and torpedo propellers. “This device is a turbomachine, just like the propeller on a submarine,” Kunz says. “When it comes to fluid dynamics, the equations are the same—no matter what the fluid. In this case it’s blood.”