This is a diseasein which the heart muscle (myocardium) becomes abnormally thick, making it harder for the heart to pump blood. Hypertrop hiccardio my opathy, while usually not fatal in most people, is the most common cause of heart-related sudden death in people under30. It's the most common cause of sudden death in athletes. HCMofien goes undetected.

Coronary artery abnormalities. Sometimes people are born with heart arteries (coronaryarteries) that are connected abnormally to the heart. The arteries can become compressed during exercise and not provide proper blood fiow to the heart.

Long QT syndrome(LQTS). Long QT syndrome(LQTS)is an inherited heart rhythm disorderthat can cause fast, chaotic heartbeats. The rapid heartbeats, caused by changes in the part ofyour heartthat causes it to beat, may lead to fainting, which can be life-threatening. In some cases, your hear Csrhythm may be so erratic that it can cause sudden death. Young people with long QT syndrome havean increased risk of sudden death.

There are many other causes of sudden cardiac death in young people. They usually affect the structure of the heart or the heart's electrical system.

There's another rare cause of sudden cardiac death that can occur in anyone, though it's usually heard about in young people who play sports. It occurs as the result of a blunt blow to the chest-suchas being hit by a baseball or hockey puck at just the right time. Its medical name is commotio cordis.The blow to the chest can trigger ventricular fibrillation if the blow strikes at exactly the wrong time inthe heart's electrical cycle.

Are there symptoms or red flags parents, coaches and others should be on the lookout forthat signal a young person is at high risk of sudden cardiac death？

Many times these deaths occur with no warning, but there are two symptoms to watch for:

Unexplained fainting(syncope). Sudden and unexplained fainting that occurs during physicalexertion could be a sign that there's a problem with your heart. Seizures also can occur.

Family history of sudden cardiac death. The other major warning sign is a family history of unexplained deaths before the age of 50. This obviously isn't a physical symptom like fainting, butdeaths like this in your family should prompt you to pay close attention and perhaps talk with yourdoctor about screening options.

Shortness of breath or chest pain may also be a sign that you're at risk of sudden cardiac death, butthese are rare and may be a sign of other health problems in young people, such as asthma.

Can sudden death in young people be prevented？

It sometimes can. If you're found to be at high risk of sudden cardiac death, your doctor will usually suggest that you avoid competitive sports. Depending on your underlying condition, medical orsurgical treatments may be recommended to reduce your risk of sudden death.

Another option for some, such as those with hypertrophic cardiomyopathy, is an implantable cardioverter-defibrillator (ICD).