Prolongation of the Q-T interval caused by sotalol--possible association with ventricular tachyarrhythmias

Autor: Markku Laakso, P J Neuvonen, Kalevi Pyörälä, P J Pentikäinen
Rok vydání: 1981
Předmět:
Zdroj: European heart journal. 2(4)
ISSN: 0195-668X
Popis: The case history of a patient is reported who had two episodes of unconsciousness while on anti-hypertensive therapy consisting of hydrochloroihiazide, hydralazine, and sotalol (480-640 mg as a single daily dose). Ventricular fibrillation which was successfully reverted to sinus rhythm was verified as the cause of the second episode. A ventricular arrhythmia might also have been the cause of the first attack. Marked prolongation of the Q- Tc interval (up to 0'68 s), which returned to normal after discontinuation of sotalol was observed in connection with the episodes. Except for sotalol, no other factors known to cause prolongation of the Q-T interval were found. Later, administration of a single dose of 640 mg of sotalol in the coronary care unit caused a reversible prolongation of the Q-T interval paralleling the course of sotalol concentration in the serum. Atenolol in a dose of 100 mg was associated with a reduction in the response of the pulse to tilting and nitroglycerin administration similar to that observed after sotalol administration, but prolongation of the Q-T interval did not occur after atenolol. Thus, the effect on the Q- T interval was not related to the beta-blocking effect of sotalol. These observations suggest that high therapeutic doses of sotalol can cause a marked prolongation of the Q-T interval which may be associated with ventricular arrhythmias
Databáze: OpenAIRE