Dr. Robert Chen
Understanding the heart’s brain: Dr. Robert Chen probes effects of birth defects on heart’s nervous system
As a pediatric cardiologist, Dr. Robert Chen helps children born with defective hearts. “A combination of genetic and environmental factors can cause the developing heart to form improperly,” explains Dr. Chen, an assistant professor in Dalhousie Medical School’s Division of Pediatric Cardiology at the IWK Health Centre and a member of the Cardiovascular Research Group. “These congenital defects range from obstructions, misplaced connections or immature structures within the heart and blood vessels, to missing parts.” About one in a hundred children is born with some form of heart defect – but serious defects occur in one in 1,000 to 1,500 children.
In his research, Dr. Chen is examining how congenital heart defects affect the function of the heart’s nervous system. “In essence, the heart has a brain of its own,” Dr. Chen says, describing how bundles of nerves around the heart, called ganglia, help it regulate its own function and relay messages between the body and the heart. “These ganglia and neurons within the heart enable the muscle cells of the heart to pump in time with each other… and to pump the amount of blood the body needs at any given time, based on activity.”
Among his many projects, Dr. Chen is investigating how a common drug, digitalis, helps regulate heart function in children with defective hearts. “We think it improves the heart’s ability to sense changes in its own environment,” says Dr. Chen. “In other words, it may function via the cardiac nervous system…but it’s important to understand the precise mechanisms.”
The cardiac nervous system is also affected by surgery. “When certain parts of the heart muscle are cut into, the nervous activity shuts down,” notes Dr. Chen. “We need to see if this nervous activity recovers, and find ways to minimize surgical damage to the heart’s nervous system.”
In addition to his laboratory and clinical studies, Dr. Chen is working with Dr. Stacy O’Blenes and others to assess how well skeletal muscle cells repair heart attack damage – and function as heart cells – when transplanted into injured hearts.