Q: Is it true back muscle can be used to pump blood through the heart?

A: Yes, a new surgical procedure called "dynamic cardiomyoplasty" uses patients' back muscles to stimulate the pumping action of their failing hearts.

Dynamic cardiomyoplasty can be used to keep a patient's heart working as an alternative for patients with severe heart disease who are ineligible for a heart transplant.

University Medical Center in Tucson, which received Food and Drug Administration approval to use the "muscle wrap" technique last December, is one of about 10 centers in the nation participating in a clinical study to determine if dynamic cardiomyoplasty is more effective than standard medical therapy for treating heart failure.

The procedure begins with surgery to free the left back muscle (the latissimus dorsi muscle) without disturbing its main blood and nerve supply. The muscle is wrapped around and attached to the heart, and then is stimulated by a special pacemaker and electrodes and trained to contract in synchrony with the heart. There is little change in the appearance of the back or in the movement of the left arm, once the muscle has been moved and the patient recovers from the procedure.

The first dynamic cardiomyoplasty was performed on a patient in 1985. Since then, more than 400 patients worldwide have received this therapy.

Jack G. Copeland, M.D., chief, cardiovascular and thoracic surgery, University Medical Center; co-director, University Heart Center at The University of Arizona College of Medicine

Q: Does a portable system exist that can pump blood through the heart?

A: A device called the Novacor left ventricular assist system (LVAS) now is portable. Surgeons at University Medical Center in Tucson have implanted this portable heart assist device in two patients.

In the past, the Novacor LVAS required a large external console, including battery, oxygen and computer equipment, that limited the patient's mobility while on the device.

The patient's heart is not removed during implantation of this device. The LVAS is attached to the patient's heart and takes over the left ventricle's function of pumping blood throughout the body. This system has been used as a bridge to transplantation in the United States since 1984. UMC first used this device in 1989 and 16 Novacor LVAS have been used since.

The new portable system includes an electromechanically driven pump implanted in theabdomen. An inflow conduit directs blood from the left ventricle into the pump. The pump pushes blood through an outflow conduit into the aorta, the central vessel of the body's arterial system.

Matching the recipient's natural heartbeat, the pump takes over the workload of the failing heart. An electronic controller and battery packs are worn on a belt around the patient's waist or carried in a shoulder bag and connected to the implanted pump by a lead through the skin.

UMC is one of only three hospitals with FDA approval to allow patients to leave the hospital while on the device.

Jack G. Copeland, M.D., chief, cardiovascular and thoracic surgery, University Medical Center; co-director, University Heart Center at The University of Arizona College of Medicine