Early heart conditions linked to later serious heart problems

The warning conditions were atrial fibrillation, an irregular heartbeat, or electrical conduction problems before age 65, and myocarditis, heart muscle inflammation, at any age. Researchers identified 6,037 people with these conditions but without the study’s outcome beforehand. The combined outcome included nonischemic cardiomyopathy—weak heart pumping not caused by reduced blood supply—or sustained abnormal rhythms in the heart’s lower chambers or sudden cardiac death. It occurred in 11% of people with warning conditions versus 1.8% of controls. Among those who developed an outcome after a warning condition, the median interval was 2.3 years. The authors suggested that people with these warning conditions may benefit from early intervention.