American Olympic bronze medallist Jenny Simpson has announced her diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) -- a rare inherited heart condition that is forcing her to give up her career as it makes running dangerous. The 39-year-old, former 1500 meters world champion, was diagnosed after collapsing in June at a community track event hosted by Sir Walter Running and required CPR. What Happened To Jenny Simpson? After receiving lifesaving care at the track event, Simpson was transferred to Duke University Hospital for more advanced heart failure support. Her heart was not pumping strongly enough, causing fluid to build up in her lungs. She described the experience as beginning to “drown.” “My body was dying, but my spirit wouldn’t give up,” her post read. “I fought for my life.” Within days, however, her heart and lungs were strong enough to function on their own. Simpson Forced To End Her Career Simpson said her diagnosis means “it would be dangerous for me to return to running.” She retired from elite racing in 2024 and described the diagnosis as the end of that chapter of her life. "I was diagnosed with a rare inherited heart condition, Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)... My future is an incredible gift. It is hopeful, and it will continue to have a great purpose. But my diagnosis also means it would be dangerous for me to return to running," Simpson said in a post on Instagram. “That chapter has ended,” the post read. “Thankfully, my story hasn’t.” Why Can ARVC Be Dangerous? Simpson was diagnosed with ARVC, a rare inherited condition in which scar tissue in the heart can disrupt its electrical system and trigger dangerous heart rhythms. The condition can weaken the heart muscle and affect its ability to pump blood effectively. It can affect one or both ventricles; when it mainly affects the right ventricle, it is called ARVC. In Simpson’s case, the abnormal heart rhythms ultimately caused her heart to stop. “As devastating as that diagnosis sounds, I truly feel profoundly fortunate. CPR, AED shocks, exceptional medical care, and a healthy body and fighting spirit that have spent a lifetime adapting to hard things all came together to give me another chance at life.” Simpson is the only US woman to win a world 1500m title, which she achieved in 2011, and one of two US women to win an Olympic 1500m medal, taking bronze in 2016. From 2007 through 2019, she finished among the top three in the 1500m, 5000m or 3000m steeplechase at all 13 USA Track and Field Outdoor Championships. What Is ARVC? In ARVC, heart muscle cells do not stick together properly, causing scar tissue and weakening the heart muscle. This can affect the heart’s ability to pump blood effectively. The condition can affect one or both ventricles. When it primarily affects the right ventricle, it is called ARVC. ARVC: SymptomsSome people may have no symptoms. Others may experience: Heart palpitations Lightheadedness Fainting Shortness of breath Abnormal heart rhythms Swelling in the ankles, legs or abdomen Chest pain or discomfort Symptoms may become more noticeable as the condition progresses. ARVC: Diagnosis Doctors may use several tests to assess the heart, including: Cardiac MRI ECG Exercise test Echocardiogram ARVC: Treatment There is no cure for ARVC, but treatment can help manage abnormal heart rhythms and reduce complications. Options may include: Pacemaker ICD Cardioversion Catheter ablation.