Narrow-complex tachycardia

A previously fit and well 52-year-old patient develops a regular narrow-complex tachycardiain recovery, but is otherwise stable with a blood pressure of 125/85mmHg. Youapply oxygen on high flow via a facemask, perform a 12-lead ECG and start carotid sinus massage, which fails to correct the tachycardia. You give adenosine 6mg intravenously,which fails to alter the rhythm, followed by a further adenosine 12mg intravenously, again with no improvement.What would you do next?

a) Give digoxin 500 mcg intravenously

b) Give amiodarone 300mg loading dose intravenously

c) Give verapamil 2.5mg intravenously over two minutes

d) Give adenosine 12mg intravenously

e) Perform synchronised DC cardioversion

Answer: d

Explanation

The patient described is stable. The Resuscitation Council (UK) recommends an ECG

during each manoeuvre. This is important as it may help to detect an underlying

arrhythmia such as atrial flutter if the heart rate slows. Carotid sinus massage failed,

so the next step would be to give adenosine as described. If this fails, you would try

one more 12mg dose of adenosine. If this fails, the verapamil should be given. Digoxin

may be of use in a stable irregular narrow-complex tachycardia , and cardioversion

may be required if the patient becomes unstable.

Reference

Nolan J. Peri-arrest arrhythmias. In: Advanced Life Support, 5th edn. London:

Resuscitation Council (UK), 2005; pp. 59–67. Online at www.resus.org.uk/pages/

periarst.pdf (Accessed 30 October 2009)