Ibutilide worked to chemically cardiovert rapid atrial fibrillation (afib) in just over half of cases but was associated with the feared complication, ventricular tachycardia (VT), in 2 patients (0.6%).
Why does this matter?
Patients may have concern over electrical cardioversion. So chemical cardioversion of afib is an option. Of note, if there is any concern over the duration of afib, such as over 48 hours, a TEE needs to be done to rule out atrial clot before chemical or electrical cardioversion. Regardless, ibultilide is one antiarrhythmic agent that can be used. It is a class III antiarrhythmic agent. It is usually given as 1mg over 10 minutes. Then the patient is observed for 10 minutes and another 1mg dose may be subsequently infused. Patients with hypokalemia, hypomagnesemia, heart failure, or long QT should not get this drug. It can cause sustained VT about 5% of the time. Patients should be monitored for 4 hours after giving it.
Just shock me...seriously
This was a multi-center retrospective review of real world ibutilide use for a-fib/flutter in 21 EDs. They identified 361 patients. The average dose given was 1.5mg. Successful chemical cardioversion occurred in 55% (50.5% in a-fib and 75% for flutter), most within 4 hours. Of the 361 people, 2 (0.6%) had VT. Older age, a-flutter, and new onset a-fib/flutter were all associated with improved odds of cardioversion. ED doctors gave it to patients with QTc >480 in 29% of patients, which was not the textbook way of doing it. This is just my opinion, but I would choose the safety and >90% acute success rate of electrical cardioversion for my patients (and myself) over ibutilide any day. Knock me out and shock me.
Ibutilide Effectiveness and Safety in the Cardioversion of Atrial Fibrillation and Flutter in the Community Emergency Department. Ann Emerg Med. 2017 Sep 29. pii: S0196-0644(17)31381-1. doi: 10.1016/j.annemergmed.2017.07.481. [Epub ahead of print]