Treatment of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

largely composed of patients referred because of their highrisk status or severe clinical manifestations requiring specialized therapeutic interventions, such as catheter ablation or implantable defibrillator (ICD). 21,27,37,38Studies from community-based patient cohorts and clinical screening of familial ARVC/D reported a much lower overall annual mortality rates (<1%). 24,30313236,39 These latter data provide a more balanced view of the natural history of ARVC/D, in which the disease may occur with no or relatively mild disability and without the necessity for major therapeutic interventions. 10,12133]14151617 The mechanism of SCD in ARVC/D is cardiac arrest due to sustained ventricular tachycardia (VT) or ventricular fibrillation (VF), which may occur as the first manifestation of the disease in young people without previous symptoms. 2,7,40ata from autopsy series and observational clinical studies on ARVC/D have provided a number of clinical predictors of adverse events and death.Table 3 reports the clinical variables identified as independent predictors of poor outcome including malignant arrhythmic events (ie, SCD, cardiac arrest due to VF, appropriate ICD interventions, or ICD therapy on fast VT/VF), non-SCD, or heart transplantation, which were found in at least one published multivariable analysis.Patients who have experienced sustained VT or VF are at highest risk of experiencing life-threatening arrhythmic events. 22233]24 Unexplained syncope has been associated with an increased arrhythmic risk in some but not in all studies. 22,25,26f note, unexplained syncope is defined as a loss of consciousness that: (i) occurs in the absence of documented ventricular arrhythmias and/or circumstances clearly leading to reflex-mediated changes in vascular tone or heart rate such as a micturition, defaecation, cough, or other similar conditions; and (ii) remains unexplained after a detailed clinical evaluation aimed to exclude other cardiac or extracardiac causes. 25ther independent risk factors for adverse events include nonsustained VT on 24-h Holter monitoring'; 25,26 dilation/ dysfunction of RV, left ventricle (LV), or both; 21,22,2728293039 male gender; 31,32 compound and digenic heterozygosity of desmosomal-gene mutations; 32 young age at the time of diagnosis; 22,23 proband status; 31 inducibility at programmed ventricular stimulation; 26,28,33 amount of electroanatomic scar 34 and electroanatomic scar-related fractionated electrograms; 35 extent of T-wave inversion across precordial and inferior leads; 23,31,36 low QRS amplitude 36 and QRS fragmentation. 36