Rhythm & Rate 9

Describe the findings in the rhythm strips of this 44 year old man who presented with epigastric discomfort, sweating and vomiting.

Visible P waves are marked with a red dot; the position of hidden P waves (marked with a orange dot) have been extrapolated from the visible P waves. There is no constant relationship between the P waves and the ventricular complexes i.e. the rhythm strips show complete heart block.

Strip A shows that the complete heart block is associated with a junctional rhythm that has a ventricular rate of between 60 beats per minute and 75 beats per minute. The ventricular rate suggests that the junctional rhythm is “accelerated” as well as being an escape rhythm.  

The ventricular complexes in the junctional rhythm have small Q waves and marked ST segment elevation. These changes result from an acute inferior infarct that has blocked conduction through the atrioventricular node.

Strip A also shows two ventricular ectopic (VE) beats that have the same shape, are close to the T wave of the preceding complex, and are the same distance from the preceding complex. They are unifocal R on T VEs with a constant coupling interval.
Strip B shows that the VEs are more frequent and have occurred as “salvoes” of three consecutive VEs and two consecutive VEs.  While it is common practice to label three or more consecutive VEs as “ventricular tachycardia” I do not use this term unless there are ten or more consecutive VE complexes.