McGill Case 359

This case report is kindly provided by Michael Rosengarten from McGill and is part of the McGill Cases. These cases come from the McGill EKG World Encyclopedia. Previous Case: McGill Case 358 | Next Case: McGill Case 360

This is a series from a young man in his 20's. the first EKG is on his presentation to the emergency room. It shows a wide complex tachycardia at 230/min. It is a RBBB configuration with a deep S wave in V6 and a tall R wave in V1. This the deep S wave in V6 could suggest ventricular tachycarida.

This a recording from a 25 year old man with palpitations. There is a dominat r' in V1 which makes this a wide complex with a right bundle branch morphology. The axis is unusual though as it is to the right (large S in lead 1). The R to S ratio in lead V6 is less than one and this favours the diagnosis of ventricular tachycardia.

This a recording rhythm strip from the same patient is after giving intravenous Adenosine. The tachycardia slows and becomes irregular and the QRS narrows. Then there is a pause and flutter waves are seen at a rate of 300/min. Note the PVCs that appear after the pause. The rhythm at the end of the recording is probably flutter with 2:1 block. It is entirely possible that the Adenosine increased the rate of this patient's flutter and hence the AV node was able to create a 2:1 block (see EKG below, note SVT in lead V1) and slow down the ventricular rate. The patient, after this recording reverted to sinus rhythm. It is not unusual that acceleration of atrial flutter with cardiac pacing produces a flutter that is less stable and which then converts spontaneously to sinus rhythm.

Below is the final EKG after the patient reverted to sinus rhythm.