Dual channel oversensing of what?
Trace category:
EGM
Device/Field:
PM
Company:
Microport CRM
66-year old patient implanted with a two-chamber pacemaker (Sorin Kora 100 DR) in 2014.
Interrogation revealed 1% ventricular pacing, stable threshold, sensitivity and impedance of both leads.
There was one episode of an atrial mode switch, which occured a few months earlier.
Does anybody have an idea what is causing the oversensing?
DR Marc Strik
Fri, 23/12/2016 - 12:06
Patient did not recall anything special that day. So no external atrial pacing.
We sent the EGM to Livanova (Paris)..
DR Piotr Szamlewski
Tue, 27/12/2016 - 01:06
I would think about placement of electrodes and atrial rhythm origin: Is the ventricular electrode placed properly in RV? It looks like CS signal... but at the same time shows the atrial iEGM a dual signal too. It could be theoretically a double counting of sinus signal/atrial focus due to a two "pathways" between sinusnode/atrial focus and atrial electrode. At the same time a far-field sense of "this second atrial signal" in RV electrode.
DR Sylvain Ploux
Wed, 28/12/2016 - 15:04
Hi Marc,
The PM senses correctly the atrial signal around 3mV, and the V signal around 8mV. A supernumerary signals is present in between, on both channels. This signal is not as sharp as the near-field ones.
Physiologically there should be nothing in between the atrial and ventricular activation. I would go for a hardware issue (Minute Ventilation algorithm or so). Let see what Livanova says about it.
Nice brain teaser!
Sylvain