Idiopathic Prolonged Long QT Interval Leading to Sudden Cardiac Arrest in an Adolescent.

Sudden cardiac arrest (SCA) can be caused by inherited and acquired conditions and can lead to sudden cardiac death. There are many causes and risk factors for SCA such as QTc prolongation which can be inherited or acquired. Potential causes of acquired QTc prolongation include medications, electrolyte abnormalities, etc. Genetic causes are less common and look at channelopathies involved in the cardiac action potential that interferes with the repolarization, causing a prolonged ventricular contraction reflected in the QTc interval. Before determining that the cause of an SCA is due to a QTc prolonged interval, a full cardiac workup needs to be done to eliminate other anatomical causes of SCA. This case report elicits an interesting clinical scenario in which a previously healthy 20-year-old male experiences SCA while playing basketball. The patient was resuscitated at the scene. After defibrillation, intubation, various imaging studies, and a subcutaneous implantable cardioverter-defibrillator (ICD) placement, the patient was diagnosed with long QTc syndrome and underwent genetic testing which was later found to be negative. Hence, understanding the causes of SCA in young patients can be important in avoiding dreadful and life-threatening situations and providing information to the patient and family members.