ROCHESTER, Minn. — At Mayo Clinic, cardiologists Peter Noseworthy, M.D., and John Giudicessi, M.D., Ph.D., are uncovering the earliest signs of a genetic heart condition that often strikes without warning. Their work shows that early detection, and even prevention, may be possible long before symptoms appear. The condition, arrhythmogenic right ventricular cardiomyopathy, weakens the molecules that hold heart cells together. As those bonds deteriorate, healthy muscle is replaced with scar tissue and fat, leaving the heart weaker. The disease often advances silently. Sometimes the first sign is when a person suddenly collapses during exercise. For many, a diagnosis comes only after the heart is already damaged. Detecting it earlier could spare patients from heart failure, the need for a transplant or sudden…