EP Q&A; Q3

A 35-year-old man presents with episodes of palpitations associated with chest discomfort and anxiety. He is referred for electrophysiologic testing and possible ablation. No tachycardias are induced during the study, but a tracing is recorded during baseline study while under sedation (above).

Which of the following is the most appropriate management?

Implantation of a permanent dual-chamber pacemaker and program the device at VVI 40 ppm.
Implantation of a permanent single-chamber pacemaker and programming of the device to VVI 40 ppm.
Implantation of a dual-chamber pacemaker and programming of the device to DDD with a lower rate limit of 60 ppm and upper rate limit of 140 ppm.
Implantation of a dual-chamber pacemaker programmed AAIR 60-140 ppm.
Initiate 30-day event recorder.

Show Answer

Answer: E

Tracing = Sinus rhythm with Mobitz I second-degree AV block (Wenckebach) and a normal QRS interval and morphology.
EGM shows progressive lengthening of AH interval before nodal block.
In a healthy subject with high vagal tone at rest, AV Wenckebach may be a normal finding. No specific therapy is warranted for this incidental finding. An event recorder would be a reasonable diagnostic test to further assess the palpitations.

Below is an example of infra-Hisian block, which is more pathologic.