What is a Sudden Cardiac Arrest (SCA)?
A Sudden cardiac arrest (SCA) is showed by a rapid pulse absence and an unconsciousness state caused by the inability of the heart to pump blood into the brain, and into the body, in an effective way. Usually sudden cardiac arrest is caused by potentially lethal arrhythmias and by some cardiac electric system abnormalities. It’s defined “sudden” because of its nature, so it can affect any person in any place without any notice, even people (individuals) who have never been previously diagnosed cardiac disease or critic clinical conditions. If sudden cardiac arrest is not treated immediately, in a few seconds, the person affected loses consciousness and for every minute passed without receiving any intervention, the percentage of surviving is reduced to 10 per cent. To save a patient’s life affected with sudden cardiac arrest is necessary to proceed with a cardiopulmonary resuscitation (CPR) and with a defibrillation, which restore the cardiac rhythm before the brain is affected by the irreversible damage caused by the lack of blood and oxygen; these events occur between 4 and 6 minutes.
What are cardiomyopathies?
Cardiomyopathies are a group of heart muscle diseases, often genetically determined with different modality of transmission, which can show symptoms that limit the functional capacity of the heart, and that involve complications such as atrial fibrillation, heart failure, stroke and, rarely, malignant ventricular arrhythmias and sudden death. Patients with different types of cardiomyopathy (hypertrophic, dilated, arrhythmogenic right ventricular cardiomyopathy, restrictive) are estimated to be about 3 per thousand of general population, but unfortunately the cardiologist notice them only when critic or deadly events occur.
Do sudden cardiac arrest and cardiomyopathies have inherited components?
In developed countries, sudden cardiac death is responsible of more than
5% of total deaths and of more of 50% of mortality for cardiovascular diseases. In Italy, it can be estimated, with a good approximation, that the incidence of this phenomenon is about 0.7/1000 inhabitants/ year.
Sudden death happens in 20-25% of cases
in apparently healthy individuals, as a first manifestation of an unacknowledged underlying pathology. The 5-10% of sudden death cases occur in absence of evident structural cardiac anomalies in structurally normal hearts (sine materia sudden death), in presence of electrophysiological disorders which determine an electric instability responsible of the onset of ventricular arrhythmias, same as the case of long QT syndrome (LQTS), the Brugada syndrome (BS), catecholaminergic polymorphic ventricular tachycardia (CPVT).