Brugada Syndrome

A familial disorder characterized by spontaneous idiopathic ventricular fibrillation that probably is one of the most frequent causes of sudden death in patients with a structurally normal heart.

Idiopathic Ventricular Fibrillation; Right Bundle Branch Block, ST-Segment Elevation, and Sudden Death Syndrome.

Prevalence is estimated to be 1:10,000 to 5:10,000 in the general population in western countries. Higher frequency (1:2500) may be found in eastern countries.

Autosomal dominant. Approximately 3/4 of clinically affected individuals are males.

Caused by mutations in the gene encoding the α-subunit of the voltage-gated sodium channel type V (SCN5A). A reentrant mechanism has been evocated. Loss of the dome of the action potential occurs because of an ion imbalance during phase 1 of the action potential. Increasing the potassium current increases ST-segment elevation, whereas interventions increasing calcium current diminish ST-segment elevation and vice versa.

Based on the typical electrocardiographic pattern of ST-segment elevation in leads V1 to V3 and incomplete or complete right bundle branch block. Genetic studies can confirm the diagnosis, but a negative result does not exclude the diagnosis.

Syncope and cardiac arrest, typically occurring in the third and fourth decade of life, usually at rest or during sleep. However, all ages can be symptomatic. Classification of patients is not clearly established, but history of syncope and spontaneous electrocardiographic modifications seems to bear a bad prognosis. Intracardiac defibrillators have been used successfully.

Obtain full familial and personal history. Evaluate cardiac status (clinical, electrocardiogram). Evaluate perioperative electrolyte levels (Na, Ca, K).

Successful anesthetic management of patients with Brugada syndrome has been described for general and regional anesthesia. Resuscitation devices must be present at all times (internal or external defibrillator). Perioperative cardiac monitoring is imperative. In high-risk patients (syncope and spontaneous electrocardiographic modifications), benefit of preoperative intracardiac defibrillator implantation must be considered.

Perioperative fluid regimen must carefully consider the absolute necessity of electrolyte equilibrium. Calcium blockers should be avoided. Amiodarone has been used successfully in some patients.

Arrhythmogenic Right Ventricular Dysplasia: Most often inherited disease of the myocardium resulting in cardiomyopathy and risk of sudden death in otherwise healthy young adults.