According to research presented at the 2016 European Society of Cardiology Congress today, sudden cardiac arrest from HCM, which has long been thought to result from exercise, is actually more likely to occur at rest, or even during sleep, according to Dr. Gherardo Finocchiaro, a cardiologist at St George’s University in London.  Dr. Finocchiaro also pointed out that of the 184 HCM patients in his study, almost 80% had no previous symptoms of HCM, and only 1 in 5 had been diagnosed with HCM before their deaths.  Interestingly, most of the sudden deaths from HCM analyzed in the study occurred in patients in their 30s and 40s.