[Electrical standstill of the heart for 24 hours after intravenous administration of verapamil (author's transl)].

In a 47-year-old man suffering from sick-sinus syndrome the sinus node recovery time was determined. During rapid atrial stimulation a supraventricular tachycardia occurred. The intravenous administration of 10 mg Verapamil was followed by total electrical standstill of the heart lasting for more than 24 hours and requiring pacemaker therapy. This case demonstrates that the intravenous administration of Verapamil may be harmful.