A Miniature Mechanical Pump Helps Weak Hearts

An implantable left ventricular assist system (LVAS) sustains patients awaiting heart transplant, gives them a better quality of life, and improved chances of survival.

The HeartMateII LVAS the HeartMate II is intended for left, right, and biventricular support for bridge-to-heart transplantation and for post-cardiotomy recovery. The device provides continuous blood flow through the circulatory system using only one moving part - a rotary pumping mechanism. At the heart of the system pump is a flattened titanium cylinder about five cm thick and 10 cm in circumference, and weighing 1.2 kg. The pump has two chambers: a blood chamber and a motor chamber. A flexible membrane separates the two, which moves up and down when pushed by the motor. The inside of the pump is made of beaded titanium, which creates a rough, textured surface. The other side is made of textured polyurethane, which helps the body form a lining inside the pump, mimicking the blood vessels. The HeartMate pump contains unidirectional valves that allow the blood flow only from the left ventricle through the pump and out to the body. The HeartMate can pump up to 10 liters per minute.

The system includes the implantable heart pump and a driveline that connects it to the system controller. The system also includes a power base unit (PB), used for charging batteries and for powering the pump while the patient is at rest, and a display module to show pump information. The device has been designed to be quieter and more durable than most other pumps, and is only one-eighth the size of the original HeartMate LVAS. The HeartMate II is manufactured by Thoratec (Pleasanton, CA, USA), and has been approved by the U.S. Food and Drug Administration (FDA).

"For patients whose hearts are unable to effectively pump blood due to severe heart failure, this remarkable device can help them have active lives as they await a heart transplant,” said Dr. Yoshifumi Naka, M.D., director of cardiac transplantation at NewYork-Presbyterian Hospital/Columbia University Medical Center (New York, NY, USA) and associate professor of surgery at Columbia University College of Physicians and Surgeons (New York, NY, USA).


Related Links:
Thoratec
NewYork-Presbyterian Hospital/Columbia University Medical Center