Question 6.3

1 Describe the ECG shown. 

2 Give two interventions that may assist in clarification as to the aetiology of this rhythm? 

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College Answer

1 Narrow complex tachycardia rate 170-200 bpm. ST depression inferiorly. Meets voltage criteria for Left ventricular hypertrophy with strain. Could be atrial flutter or atrial fibrillation or SVT

2 Either carotid sinus massage (after auscultation of carotids to exclude bruit) or other vagal manoeuvre or administration of push dose of adenosine if no asthma.


This SVT question addresses the candidate's knowledge of the most recent resuscitation guidelines for the management of hemodynamically unstable narrow-complex tachycardia.Unable to locate an ECG with the specific features which the college wanted, I was limited in what I could post up there, and ultimately I settled on an SVT without any features of ischaemia and only the barest hint of LVH.


One may turn to the ARC guidelines for management of supraventricular tachycardias (guideline 11.9), which suggests (Class A evidence) that in a stable patient, vagal manoeuvres ought to be tried and then adenosine may be used unless contraindications exist. An unstable patient may also have a trial of adenosine while a defibrillator is being acquired, or while the chest is being shaved etc.....

As their reference for this set of guidelines, the ARC quote the ACC's statement.