Same patient as for tracing 1 of pacing mode chapter; the patient is in AV block; he underwent pacemaker interrogation 3 days after device implantation; programming of various pacing modes and recording of the tracings; DDD mode programming.
Tracing 1a: the first channel is lead I of the surface ECG with the markers superimposed, the second shows the time intervals, the third is lead III and the last channel is lead II;
Tracing 1b: the episode of AF lasted 2 minutes before spontaneous conversion; new tracing in DDD mode at 60 bpm;
Tracing 1c: change of programming to MVP mode at 70 bpm;
2 factors are determinant in the management of atrial arrhythmias in recipients of cardiac pacemakers: fallback must be systematically programmed to prevent rapid ventricular pacing during abnormal acceleration of the atrial rhythm; algorithms can be implemented to alleviate the arrhythmia burden.
This tracing illustrates important points:
1) an Adapta pacemaker switches mode for episodes of atrial arrhythmias based on the following criteria: out of 7 consecutive intervals, 4 are shorter than the programmed rate detection interval (in this case 175 bpm);
2) the efficacy of the various pacing algorithms in lowering the arrhythmia burden varies depending on the patient and remains to be confirmed in a large population.
The tracings recorded in this patient are, nevertheless, promising. The episode of AF began with an atrial extrasystole, sensed with any pacing mode with a backup rate at 60 bpm. An increase in the backup rate to 70 bpm and the programming of the MVP mode completely suppressed the atrial extrasystoles. The suppression of the trigger, known to initiate episodes of atrial arrhythmias, might lower the arrhythmia burden and, in this patient, highlights the particular benefit of programming an algorithm that stabilizes the atrial rhythm, promotes atrial pacing, and eliminates the compensatory pauses occurring after atrial extrasystoles. The efficacy of this type of algorithm remains to be confirmed in a large population.
