S Amiodarone Cardiac arrest: case reportA 55-year-old man developed cardiac arrest following the administration of amiodarone.The man, with a history of tetralogy of fallot, presented with palpitations and lightheadedness. On admission, he was noted to have a supraventricular tachycardia. He received a 150mg dose of IV amiodarone in his left antecubital vein over a period of 10 minutes. Seven minutes later, he experienced a prolonged sinus node arrest during which he became significantly hypotensive.Epinephrine was administrated with a recovery of normal sinus rhythm. The man's heart CT scan revealed a persistent left superior vena cava (PLSVC) draining directly into the left atrium. The amiodarone was thought to be highly concentrated in the left atrium via direct drainage from the PLSVC without the diluting effect of the pulmonary circulation, thus suppressing subsidiary escape rhythms and resulting in the cardiac arrest.Author comment: "Antiarrhythmic medication administration through left-sided intravenous access in patients with a PLSVC may be at risk for cardiac arrest."