A 15-year-old boy presented in an unconscious state and on connecting the ECG electrodes, atrial fibrillation was diagnosed. The relatives told the doctor that the boy had similar episodes of syncope in the past as well. Lab studies revealed normal potassium and calcium levels, normal CK-MB levels. The patient died of cardiac arrest and could not be revived. When the previous records were checked some undue abnormality was noted in the ECGs. There was also a history of sudden cardiac death in the family. What is the most likely defect in the above patient: -
High-Yield Explanation
THIS IS A CLASSICAL CASE OF BRUGADA SYNDROME. Syncope and cardiac arrest are the most common clinical manifestations leading to the diagnosis of Brugada syndrome. Males are more commonly affected than females. Mutations involving cardiac sodium channels (SCN5A) are identified in ~25% of cases. Administration of the sodium channel blocking drug flecainide, ajmaline, or procainamide can augment ST elevation in affected individuals. An ICD is indicated for individuals who have had unexplained syncope or been resuscitated from cardiac arrest.