Harnessing the heart's own proteins:
Dr. Robert Rose seeks a path to preventing arrhythmias and heart failure
Dr. Robert Rose wants to use proteins produced naturally in the body to treat and even prevent the lagging and irregular heartbeats that develop as we age. As he explains, our heart rate gradually diminishes over time, as connective tissue builds up and forms scar-like deposits throughout the area known as the sinus node. This process, called fibrosis, leads to dangerous arrhythmias and also to heart failure.
"The sinus node is like our heart's own internal pacemaker – every time it generates an electrical impulse, our heart makes a beat," says Dr. Rose, an assistant professor in the Department of Physiology & Biophysics at Dalhousie Medical School. "As connective tissue builds up in the sinus node, it blocks, distorts or slows down these beat-keeping electrical impulses."
The end result of a compromised sinus node is a slower or irregular heart rhythm. A slow heart rate leads to fatigue and an overall decline in health, while an arrhythmia can trigger sudden death - especially in heart failure patients. Pacemakers help the heart maintain a steady beat, but they have their limitations.
Dr. Rose and his team are studying how small protein molecules called natriuretic peptides counteract the processes leading to fibrosis of the heart. These peptides seem to prevent fibrosis very well in younger people, but become less and less effective with age. "We are exploring the various receptors and cellular pathways that allow these proteins to prevent damage, so we can find ways to harness their healing potential," he says. "Perhaps the receptors don't work as well as people get older and could be reactivated, or flooded with higher levels of proteins, to repair existing scars and prevent further scarring."