Sudden Cardiac Death Syndrome: Age, Gender, Ethnicity, and Genetics

Prevention of sudden cardiac death (SCD) is an important issue in clinical practice. Causes of SCD depend on age, gender, ethnicity, and genetics. It can not be overstated that an accurate clinical judgment along with a diligent diagnostic work-up is essential. Ahistory of prior syncope especially more than once, a family history of premature death (e.g., ＜60 years of age), a critical lesion in the coronary artery, poor left ventricular function (e.g., EF＜35%), and abnormal ECG findings (e.g., QTc＞450 msec) should alert a physician about the risk of SCD. As a rule, physical exertion is prohibited in any patient with active myocardial ischemia associated with atherosclerotic coronary heart disease (ASHD), and total revascularization as early as possible is mandatory for the prevention of SCD. Special consideration should be given to women with ASHD as they often present with atypical symptomatology associated with a worse prognosis. Other cardiac diseases such as various forms of cardiomyopathies, valvular hear disease, congenital heart disease, and electrical disorders such as congenital long QT syndrome and Brugada syndrome, particularly in the young, can often be suspected. According to the each individual disease condition, the diagnostic and therapeutic strategies should be individually tailored. Life style adjustment and/or modification, medical therapy, catheter ablation, device implantation (e.g., pacemaker or implantable cardioverter/defibrillator) or surgical intervention should be appropriately advised. Molecular genetic analysis in autopsy-negative cases (molecular autopsy) is indicated for identifying the likely cause of SCD and this should be extended to the surviving relatives of the SCD victim for risk stratification, for reproductive counseling, and for taking preventive measures in the surviving family members.