Có mối liên quan giữa đột biến di truyền đặc biệt (nếu nhận dạng) và nguy cơ của Đối với phân tầng nguy cơ, trẻ tuổi trình bày triệu chứng, lịch sử gia đình của SCD, và lịch sử của ngừng tim là những hoạch định variably mạnh mẽ của SCD | EDUCATION IN HEART Figure An example of the rare arrhythmia termed catecholamine sensitive polymorphic ventricular tachycardia . This was recorded from a 19 year old white female presenting with syncope and palpitation. Note the alternating QRS morphology said to be a hallmark of the condition. polymorphic ventricular tachycardia torsades de pointe can be generated. There are associations between specific genetic mutations if identifiable and risk of For risk stratification young age at symptomatic presentation family history of SCD and history of cardiac arrest are variably powerful markers of SCD risk but interpretation of ambulatory monitoring exercise stress testing and T wave alternans are unproven. There are no currently available electrical provocation tests to aid assessment. p Blockade other antiarrhythmic drugs atrial pacing and ICD implantation may all be indicated. Brugada syndrome Patients with Brugada syndrome are predominantly male and in the third to fourth decades of life. Symptomatic presentation is with syncope or cardiac arrest in the absence of structural heart disease. In its most typical form the sufferer s ECG shows a characteristic pattern comprising a right bundle branch-like ECG configuration with ST segment elevation in leads V1 to Changes in autonomic tone or intravenous administration of sodium channel blocking drugs ajmaline flecainide procainamide can unmask ECG features. There is evidence that transmyocardial differential in action potential characteristics particularly in the right ventricular free wall epicardium facilitates re-entry during phase 2 of the action potential resulting in closely coupled cycles of ventricular activation which then precipitate ventricular fibrillation. Death occurs as a result of rapid polymorphic ventricular tachycardia often initiated during rest or sleep rather than after symptomatic ventricular tachycardia. However exhibition of these ECG changes may be variable both between and
