Snapshot A 57-year-old woman presents to the emergency department after fainting. He was accompanied by his wife who witnessed the event. He was in his usual state of health until he developed palpitations that eventually resulted in him falling to the ground. He was unresponsive and the emergency medical services were called. Medical history is significant for a recent myocardial infarction. On physical exam he is unresponsive and no pulse is present. An electrocardiogram demonstrates a tachyarrhythmia with irregular QRS complexes of variable amplitude and morphology. (Ventricular fibrillation) Introduction A group of ventricular arrhythmias that include ventricular premature beats action potentials are ectopically generated within the ventricles typically benign and asymptomatic ventricular tachycardia if sustained ventricular tachycardia is not managed, it can result in ventricular fibrillation ventricular fibrillation life-threatening, if not immediately managed Epidemiology risk factors myocardial ischemia and infarction ventricular hypertrophy long QT syndromes valvular heart disease congenital cardiac abnormalities Symptoms palpitations symptoms of heart failure, which include shortness of breath chest discomfort syncope cardiac arrest Ventricular Arrhythmias Type Electrocardiogram Findings Treatment Ventricular premature beats (VPBs) Widened QRS complex with abnormal morphology Typically with reassurance or a β-blocker in healthy patients Ventricular tachycardia 3 or more consecutive VPBs, displaying abroad QRS complex tachyarrhythmia Stable amiodarone lidocaine procainamide Unstable synchronized cardioversion Pulseless ventricular tachycardia defibrillation Ventricular fibrillation Erratic rhythm with no discernable waves (P, QRS, or T waves) Defibrillation for all patients