Prevention of sudden cardiac death in the young and in athletes: dream or reality?

Cardiovascular diseases account for 40% of all deaths in the Western countries, and nearly two thirds of them occur suddenly. Young people (<35 years) are not spared from sudden death (SD) with a rate of 1/100,000 per year. Effort is a trigger with a threefold risk in athletes vs. nonathletes, and sports disqualification is by itself life-saving in people with underlying concealed cardiovascular diseases. Several culprits of cardiac SD may be identified at postmortem and atherosclerotic coronary artery disease is the leading cause (25% of SD cases in the young), mostly consisting of a single obstructive plaque with fibrocellular intimal proliferation. However, the spectrum of cardiovascular substrates is wide and include also congenital diseases of the coronary arteries (mainly anomalous origin), myocardium (arrhythmogenic and hypertrophic cardiomyopathies, myocarditis), valves (aortic stenosis and mitral valve prolapse), and conduction system (ventricular preexcitation, accelerated atrioventricular conduction and block). In up to 20% of cases, the heart is grossly and histologically normal at autopsy (unexplained SD or "mors sine materia"), and inherited ion channel diseases have been implicated (long and short QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia). Targets to treat and prevent SD in the young consist of the following: (a) avoid triggers like effort or emotion, (b) inhibit the onset of arrhythmias with drugs or ablation, (c) switch off arrhythmias with defibrillator, and (d) hinder the recurrence of the disease with genetic counseling and/or therapy. In vivo detection of cardiomyopathies is nowadays feasible by electrocardiogram and/or echocardiography, which resulted in a sharp decline of SD in the athletes in Italy, thanks to obligatory preparticipation screening for sport activity. Genetic screening could play a pivotal role in early detection of asymptomatic mutation carriers of cardiovascular diseases at risk of SD.