Arrhythmogenic cardiomyopathy of the right and / or left ventricle (ACM) is a disease of the ventricular myocardium characterized by the presence of areas of fibrosis (scar tissue) to replace myocardial tissue (heart muscle) in some areas of the wall of the right and / or left ventricle, and by dilation of the right and / or left ventricle. In severe cases it can even spread to both ventricles, which are dilated.
Left and right arrhythmogenic cardiomyopathy: fibrosis of the walls, increased cavity and reduced contractile force of the right and / or left ventricle, with associated ventricular arrhythmias, including threatening ones (ventricular tachycardia or ventricular fibrillation)
To recognize and diagnose ACM is not easy, particularly when the anomalies are in the initial phase and limited to some areas, hardly. Careful evaluation of the ECG and right ventricular walls by echocardiography should suggest a diagnosis. The suspicion often arises then in the presence of arrhythmias, premature atrial and ventricular beats (extrasystoles), often triggered by exertion. In some patients more complex arrhythmias (Sustained ventricular tachycardia or Ventricular fibrillation) can be life-threatening, lead to sudden unconsciousness (syncopes) and / or lead to cardiac arrest.
ACM is among the most frequent causes of unexpected death among young athletes.
It is a genetic disease. The three main genes that cause ACM among those identified so far encode three different proteins, (Plakophilin, Desmoplakin e Plakoglobin), which form the "contacts" between one cell and another in the heart, called intercellular junctions or "Desmosomes". As a consequence of genetic mutations, these proteins are defective and can cause rupture of cell-cell junctions, and therefore their disappearance, replaced by fibrotic scar tissue associated with localized or diffuse ventricular dilation.
As in other Cardiomyopathies the probability of identifying the responsible mutation is higher if one or more family members suddenly died at a young age, or if there are other family members with cardiomyopathy.