[IS THERE ANY WAY TO MAGNIFY THE ECG??]
The ECG displayed here shows a single ventricular premature beat followed by a compensatory pause and then a 10 beat run of a non-sustained, wide complex tachycardia having the same QRS morphology as the premature beat. Setting calipers to determine the sinus PP interval (0.68seconds in this example) and then marching this interval through the wide QRS complexes reveals the following:
- the slight differences in the shape of the T wave in the 2nd, 5th and 8th beats of the ten beat run are caused by superimposed P waves.
- the other sinus P waves are contained within the QRS complexes of the 1st, 4th, 7th and 10th beats of the run,
- the P wave following the last beat of the run occurs at precisely its expected time.
This, then, is an example of non-sustained ventricular tachycardia during which there is atrio-ventricular (AV) dissociation.