Pulseless ventricular tachycardia – why did the AED not advise a shock?

This case was submitted by my friend Dr. Victoria Stephens.  She is a third year Emergency Medicine Registrar from at the University of the Witwatersrand in Johannesburg, South Africa, and a great asset to FOAMed.  Follow her on Twitter: @EMcardiac.CaseA 71 year old man was admitted to the ICU with neutropenic sepsis complicated by septic shock. He was intubated and ventilated and was started on an adrenaline infusion to maintain his blood pressure. The admission ECG was normal. Thirty-six hours into his ICU stay he went into a cardiac arrest. The monitor showed a wide complex tachycardia. CPR was commenced while the defibrillator was brought to the bedside. A doctor was called from the ED to assist. The pads were attached to the patient and the defib was placed in AED mode by the nurse. The following rhythm strip was recorded (on a separate monitor from the AED, of course):A rhythm strip recorded from lead II. A wide complex tachycardia is present with a rate of approximately 170 BPM. The QRS duration is very wide.  It is regular and monomorphic and all but diagnostic of VT.The code blue team recognized that the rhythm was ventricular tachycardia and that immediate defibrillation was required. They waited for the AED function on the defib to recommend a shock. Instead, it kept saying “…analysing…analysing”.  No shock was advised. The doctor could not remember how to operate the manual mode of the AED defibrillator (this was an AED th...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs