Long Q-T syndrome precipitated by atropine and hypokalemia.

In a small child successfully treated with atropine sulfate and other drugs because of pesticide poisoning, a prolongation of the Q-T interval, extrasystolic ventricular tachyarrhythmia complicated by ventricular fibrillation and cardiac syncope, was observed. At the time of this incident the child was hypokalemic. After compensation of hypokalemia, reduction of atropine dose and subsequent discontinuation of the drug, the changes in the patient's follow-up ECG records disappeared. Thus, the use of atropine in the presence of hypokalemia should be included in the list of factors releasing the long Q-T syndrome.