65 years old man implanted with a triple chamber defibrillator Viva XT CRT-D for idiopathic dilated cardiomyopathy with left bundle branch block; 3 months post implant interrogation;
The first line correspond to an electrocardiographic derivation with superimposed markers, the second line correspond to the bipolar right ventricular EGM (EGM3) and the third line to the bipolar atrial recording (EGM1),
This tracing shows the operating function of this algorithm when the atrioventricular conduction is considered normal (delay between the spontaneous atrial EGM or the atrial stimulus and the spontaneous right ventricular EGM <200 ms and <250 ms respectively) and the the heart rate is < 100 bpm. An isolated left ventricular pacing mode is programmed in these conditions (auto LV mode). This prevents the right ventricular stimulation, reduce the energy consumption of the device and possibly extend the batteries lifespan. The post-ventricular pacing ventricular blanking period should be programmed long enough (> 200 ms) in a unique left ventricular pacing configuration to minimize the risk of detecting the paced ventriculogram.
