D00 mode

Patient

Same patient as previous tracing; device programmed to DOO mode;

Trace

On this tracing, there is regular atrial and ventricular pacing at a rate of 40 bpm; atrial and ventricular capture is effective only when it occurs outside the myocardial (atrial and ventricular) refractory periods; this pacing is asynchronous, atrial and ventricular activities are not sensed and therefore cannot inhibit pacing; when ventricular pacing occurs at the peak of the T wave, there is capture with an arrhythmogenic risk;

Trace

The EGMs show that the atrial and ventricular signals are tall but not sensed (mode DOO) explaining the asynchronous pacing;

Exergue

Pacing in a ventricular or atrial vulnerable period can be arrhythmogenic and favor the occurrence of a ventricular or atrial arrhythmia which is most often polymorphic;