A nurse is preparing a medication to administer to a patient…

A nurse is preparing a medication to administer to a patient with a very rapid heart rate.  The EKG is reading supraventricular tachycardia.  The student nurse asks how the medicine works. The nurse responds that the medication will help restore normal sinus rhythm but may cause a short period of asystole immediately after administration.  What medication is about to be administered? _______________Answers must be spelled correctly within one letter difference of the correct spelling.  Brand name or generic name will be accepted.