Abstract

Rhythm puzzle—answer The ECG shown in Fig. 1 is a narrow complex tachycardia with a frequency of 270 beats/min. Contradictory to expectations, the administration of adenosine resulted not in conversion of the arrhythmia, but in this accelerated rhythm, making an AV(N)RT unlikely. Neither did it slow down the ventricular response rate, as would be expected during atrial tachycardia or atrial flutter. Several case reports have been described where adenosine caused an accelerated AV conduction during atrial flutter, leading to 1:1 conduction.[1] This is thought to be a result of increased sympathetic tone, caused by a direct effect of adenosine on the afferent sympathetic system.[2] On the other hand, as adenosine blocks the AV node, this can cause preferential conduction of an atrial tachycardia or atrial flutter over an accessory pathway, resulting in an accelerated ventricular response.[3] However, since the QRS of the resultant tachycardia remains narrow this must be an atria-Hisian bypass tract (Lown-Ganong-Levine syndrome). Fig. 1 ECG after administration of adenosine The patient was referred for electrophysiological treatment of the flutter. No accessory bundle was identified. An atrial flutter circuit was ablated. The most likely explanation of the ECG shown in Fig. 1 is an atrial flutter with 1:1 atrioventricular conduction caused by increased sympathetic tone after administration of adenosine.

Highlights

  • This article is published with open access at Springerlink.com

  • A 65 year-old lady was seen in our emergency department with palpitations, which had been present for several hours

  • In lead V1 each QRS complex is preceded by a P wave with positive configuration

Read more

Summary

Introduction

Published online: 5 December 2014 # The Author(s) 2014. This article is published with open access at Springerlink.com

Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.