Fine-tuning heart repair:

Dr. Stacy O’Blenes tests muscle cell transplants and new surgical techniques

Unlike many body tissues, heart muscle cells don’t regenerate after they’ve been injured. That’s why Dr. Stacy O’Blenes and a team of researchers in Dalhousie Medical School’s Cardiovascular Research Group are transplanting skeletal muscle cells into injured hearts. They want to see how well the cells repair heart attack damage.

Dr. O’Blenes is carrying forward the pioneering work of Dr. Magda Horackova. Now retired from Dalhousie’s Department of Physiology & Biophysics, Dr. Horackova developed a way to engineer muscle pre-cursor cells – called myoblasts – to behave like heart muscle cells when injected into injured hearts. She is still involved in the heart repair work she began.

“We are now trying to boost the transplanted cells’ ability to repair the injured heart,” says Dr. O’Blenes, an assistant professor in the Division of Cardiac Surgery and a cardiac surgeon at the QEII Health Sciences Centre and IWK Health Centre. “Timing is one key, but we are also testing growth factors and other agents that may improve the grafting process.”

Dr. O’Blenes is working with cardiologists Dr. John Sapp and Dr. Rob Chen to see if the electrical activity of the transplanted cells is in sync with the rest of the heart muscle. “This is critical to avoid potentially dangerous rhythm problems,” he says. The researchers are performing these tests using echocardiographic equipment purchased through the proceeds of the 2003 Molly Appeal.

Dr. O’Blenes is working with fellow surgeon Dr. Camille Hancock-Friesen and pharmacologist Dr. Susan Howlett to test a new way to protect the heart during surgery. “We use cold solutions and other methods to stop the heart from beating, so we can operate,” he explains. “This means there is no blood, and no oxygen, in the heart during the procedure. This lack of oxygen can lead to what’s known as ischemic injury.” Traditional solutions need to be given every 20 minutes, which slows the operation and increases the chance of injury. “We’re testing a new solution that needs to be given only once, to see if it is as beneficial for adults as it has proven to be for children.”