EKG of the Week 2017 1-8

This EKG comes courtesy of Dr. Braden Fichter.

A 33 year old Emergency Medicine Doctor worked five night shifts in a row. He then stayed up all night the next night drinking coffee. He woke up the next day with palpitations and fatigue.

His EKG is below.

1.    What is the rhythm? 

2.    How would you manage this patient?



The rhythm is Atrial tachycardia.

Adenosine is often effective for atrial tachycardia. Beta blockers and calcium channel blockers are other options.


The EKG shows a narrow complex, regular tachycardia. There are P waves present, however the P waves do not conform to a normal sinus morphology. (They are inverted in leads II, III, aVF, V3-V6 and upright in aVR.) So, this is not a sinus rhythm.

This patient had an EP study which showed the rhythm to be adult onset ectopic atrial tachycardia. It was treated with catheter ablation.

Atrial tachycardia can present with varying degrees of AV block, similar to atrial flutter.

Patients who have had cardiac surgery are at increased risk of atrial tachycardia, particularly if an incision was made in the atrium.

There is very little data on the treatment of atrial tachycardia. Adenosine works in 60-80% of cases. The mechanism of this is unclear, but it appears to be due to an antiadrenergic effect of adenosine on atrial tissue. Beta blockers or calcium channel blockers may also be effective. For arrhythmias resistant to medications, or in patients who are unstable, treatment of choice is electrical cardioversion.


Markowitz et al. Differential Effects of Adenosine on Focal and Macroreentrant Atrial Tachycardia. J Cardiovasc Electrophysiol 1999;10:489–502

ACC Guidelines for the Management of Patients With Supraventricular Arrhythmias. JACC 2003;42:1493-1531