Pseudo-Wenckebach in Pacemaker Rhythm

Report:

Sinus tachycardia 100/min 1

Atrial-sensing ventricular pacemaker 2

Pseudo-Wenckebach periods 7

Comment:

There is no acceleration of the distal chamber because the increases in AV interval are not decremental as in the “natural” Wenckebach; otherwise, the Wenckebach “footprints” and all are there.

It is unclear why the programmed Wenckebach-like block should occur at a relatively slow atrial rate of 100/min. Somebody must have programmed it so. Another recording taken a few minutes earlier is shown below.

AV block protects the patient from very fast atrial rates and features in most new DDD units35. I could get no clinical reason from the patient’s physician why the upper rate limit was set so low.

Fig 56a. It is uncertain whether the atrial spikes contribute or not to the ensuing P waves; judging from the P wave contour, probably not.

Fig 57. 68 year old woman with a permanent pacemaker. She may have more than conduction problems.

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