Trace 4.10: Pacemaker mediated tachycardia
Patient information
Same patient as in the previous trace; programming of the algorithm for terminating pacemaker mediated tachycardias
ECG
Question
Regarding this ECG, which of the following is/are the correct answer(s)?
Comments
ECG description
This is the same tachycardia as in the previous trace (PMT); it stops for one cycle and resumes on the next cycle;
Explanation
Trace description
Analysis of the EGM allows for a diagnosis; initially, a PMT is detected; programming of the PMT termination algorithm (programming successful); the device diagnoses a PMT after 8 consecutive VP-AS cycles; the PMT termination algorithm is triggered, extending the post-ventricular atrial refractory period to 400 ms for one cycle; atrial activity is detected during the post-ventricular atrial refractory period (PVARP) and does not synchronize with ventricular pacing; the subsequent atrial pacing is ineffective, promoting retrograde conduction, and the tachycardia restarts;
Trace description
EGM trace showing the interruption of the PMT;
Trace description
ECG showing the interruption of the PMT;
To remember
Management of PMTs involves programming a specific termination algorithm, setting a PVARP longer than the retrograde conduction time (which can sometimes be difficult because it limits the ability to monitor atrial activity in 1:1 rhythm during exercise), and the prevention of episodes by eliminating triggering factors (stimulation or detection failures, false detections, etc.).
