Few people die suddenly from cardiomyopathy while exercising

29th September 2016

Most people who die suddenly from hypertrophic cardiomyopathy (HCM) are not exercising, confirms another study.

The only exception is young men who, in the study from St George’s Hospital in London, died mostly on a football pitch or a basketball court.

Dr Gerardo Finocchiaro, from the hospital, reported on the study to the European Society of Cardiology’s annual congress earlier this month.

He reported that in 184 cases of people with HCM who had suddenly from a cardiac arrest, 78% were resting, 12% sleeping and only 19% were exerting themselves.

Only one in five of those who died knew they had the disease.

He said those who had been diagnosed with HCM and died were considered to be at low risk by current methods of assessing the risk.

Dr Finocchiaro said: "We know that there are patients who unfortunately die suddenly, even if they have zero or just one risk factor."

Exercise is considered to be a trigger for dangerous heart rhythms in HCM, and both American and European guidelines recommend advising people with known HCM to avoid competitive sports, Dr Finocchiaro noted.

However, the role of sports and exercise in developing dangerous heart rhythms and the amount of exercise-induced cardiac arrest in patients with HCM is still not well understood.

So Dr Finocchiaro and his research colleagues conducted the study to try to characterise the risk factors for an exercise-induced cardiac arrest.

From 1994 to 2014, the cases of 3,684 people who died suddenly from heart problems were referred to the hospital’s heart pathology centre, of which 184 had HCM.

They had all had a detailed post-mortem. The researchers also got clinical information from the referring coroners.

The patients ranged in age from younger than 10 to older than 60, with a mean age of 39, and 79% were male.

Only 37 (20%) had an established diagnosis of HCM before their deaths. Forty (22%) had shown heart symptoms, including palpitations (16 patients), breathing problems (11), temporary loss of consciousness (seven), and chest pain (six).

Twenty patients (11%) were recreational or competitive athletes and exercised more than three hours a week.

Older people had a slightly lower risk of dying suddenly on exertion and men had a 3.5-fold higher risk of dying during exercise.