ECG Quiz

Monitor screen shot for rhythm analysis. 

Post your answers as comments below.

Highlighted comment and reply:

Comment: This is irregular broad complex tachycardia followed by irregular narrow complex tachycardia.

Rhythm strip shows narrow complexes in the beginning then broad complex irregular tachycardia with short RR interval, 2 morphologies of QRS seen.

Narrow complex tachycardia changing into wide complex tachycardia shows presence of accessory pathway. Since its irregular and I’m not able to appreciate P waves on baseline so AFib.

Reply: Underlying rhythm is AFib as there are no P waves and it is an irregular rhythm. Wide QRS tachycardia in AFib with accessory pathway is unlikely to occur in such short spells as the impulses are conducted simultaneously down both the accessory pathway and the AV nodal pathway through out. If the complexes were typical triphasic complexes, aberrant conduction (Ashman phenomenon) followed by concealed transseptal conduction could be a possibility. But here they are monophasic complexes suggestive of non sustained ventricular tachycardia. It may be noted that the RR interval of the wide QRS complexes is almost constant and shorter than RR intervals of the narrow QRS complexes.