Unique and guided training + 800 clinical cases in the data bank
GOOD ANSWER : RV lead fracture/insulation breach
•Cloud of points on the tachogram. No train tracks. Atrial rate remains stable.
GOOD ANSWER : VF/VT
GOOD ANSWER : T wave oversensing
T-Wave Oversensing: “Train tracks”
Why do the train tracks begin to separate?
GOOD ANSWER : RV Lead Dislodgement/ P wave oversensing
•RV Lead Dislodgement: One month post device implant. Double counting. Double counting of P wave and R wave. Look at the interval between oversensed signals and most consistent with PR interval. Look at morphology of oversensed signal as well and most consistent with far field P wave.
GOOD ANSWER : SVT + aberrant atrioventricular conduction
RID - : morphology different from the reference; 3 possibilities: VT, dual tachycardia, SVT + aberrant conduction Afib: 2 possibilities: dual tachycardia, SVT + aberrant conduction Unstb: in favor of SVT + aberrant conduction
GOOD ANSWERS :
Slow VT episode with AV dissociation. Very wide ventricular EGMs were double sensed. The second ventricular EGM was sensed after the post-sensed ventricular refractory period.
GOOD ANSWER : T-wave oversensing
•T-wave oversensing
GOOD ANSWER : This is a burst during the charge
Fast tachycardia detected in the VF zone; diagnosis of VF after 12 F cycles;
burst during the charge + capacitors charge; termination of the arrhythmia; however, the number of VS was insufficient to fill the counter of sinus rhythm restoration (only 3 VS cycles instead of 5 needed: return to sinus programmed to 5); continuation of the capacitors charge; early recurrence of the arrhythmia; electrical shock at the end of charge; interruption of the arrhythmia and diagnosis of return to sinus rhythm.
The programmed pacing mode is DDD with Rythmiq On (AAI with VVI backup pacing); the minimal programmed pacing rate is 60 bpm since VVI pacing is delivered at 45 bpm (15 bpm slower than the programmed minimal pacing rate); therefore the maximal duration of the ventricular pause is 1333 ms (45 bpm) and the maximal duration of the atrial pause is 1OOO ms (60 bpm)
Marker 1: sinus tachycardia; after 16 consecutive cycles AS-VP-MT (spontaneous atrial activation and paced ventricle at the maximal tracking rate) with stable VP-AS interval, suspicion of PMT and prolongation of the PRAPV during one cycle explaining the cycle (AS) and the absence of ventricular pacing on one cycle
Marker 2: sustained aspect of 2/1 corresponding to the intervention of the Rythmiq algorithm (search AV +); once the device has switched to DDD mode, prolongation of the AV delay during 8 consecutive cycles to search for a spontaneous ventricular activation; in this patient during exercise, the prolongation of the AV delay induces this aspect of 2/1 (1/2 atrial activation is in the PRAPV);
In Boston Scientific devices, the number of required consecutive VP-AS cycles is 16 For the other 4 companies, 8 consecutive VP-AS are required
Inappropriate commutation to DDD-mode (no AV-block) induced by ventricular undersensing
Ineffective LV pacing; LV pacing captures the left atrium; atrial depolarization is sensed by the right atrial channel after a conduction delay between right and left atria; The LV lead had dislodged.
Atrial tachycardia and BiV stimulation. Paced ventricular events are sensed in the atrium (V/A cross-talk). A/V oversensing with sensing of the atrial signal by the ventricular channel and inhibition of BiV stimulation, resulting in a 2-3 seconds pause.
This is an episode of VT diagnosed SVT by the device based on single-lead discrimination: for the device the absence of onset is in favor of a sinus tachycardia.
In this tracing we observe post-VP and post-VS T wave oversensing and AV crosstalk with pacing at the end of the safety window (100 ms)
GOOD ANSWER : Secure Sense is triggered by 2 out of 3 fast ventricular events
GOOD ANSWER :
GOOD ANSWER : DDI is the « episode » pacing mode
GOOD ANSWER : AAI 75bpm
Atrial pacing without V synchronization. Rhytmiq would have triggered ventricular pacing at 1000ms interval (602/min).