Inappropriate ICD shocks are not benign events. They can have profound psychological consequences for the patient, they can trigger ventricular dysrhythmias, and perhaps most importantly, they deplete the battery life of the device. Each shock reduces the battery longevity by about 30 days.
Often, paramedics (and many physicians) are reluctant to disable ICDs. That’s because we’re generally not experts when it comes to implantable medical devices. However, we should be experts in advanced cardiac life support.
Albert Einstein once said that the definition of insanity is doing the same thing over and over again and expecting a different result. If the ICD has shocked the patient 10, 11, or 12 times without a positive effect, why would we expect a benefit from shock number 13, 14, or 15?
I’m familiar with one case where a patient was hypokalemic which caused a prolonged QT interval with subsequent runs of torsades. The device shocked the patient incessantly but the torsades kept coming back until the potassium was replaced.
It’s important to consider the underlying cause.
For the case presented in Part 1, the ICD is shocking a relatively slow wide complex tachycardia that is well tolerated by the patient. Would you shock it? If not, then you probably shouldn’t let the ICD shock it either.
Consider this algorithm from Emergency management of arrhythmias and/or shocks in patients with implantable cardioverter defibrillators (ICDs). A statement on behalf of the Resuscitation Council (UK), Heart Rhythm UK (formerly The British Pacing and Electrophysiology Group, BPEG), The Joint Royal Colleges Ambulance Liaison Committee (JRCALC) and the Ambulance Services Association (ASA). Resuscitation, Volume 71, Issue 3, Pages 278-282
Apply defibrillator pads as a backup. If the device is in the upper-right chest consider anterior-posterior pad placement.
Most of the time an ICD will bÂ implanted in the patient’s upper-left chest, so standard anterior-lateral pad placement works just fine.
In Part 3 we will go over the specifics of ring magnet application.
Inappropriate or ineffective ICD shocks Part 2