Automatic pacemaker Iris series

The iECG completes the set of electrograms recorded in the IRIS family: the band-pass filtered atrial and ventricular EGMs (supporting the pacemaker sensing function) and the corresponding wide-band EGMs, which allow a first step evaluation of signal morphology and duration. The iECG further improves this feature, providing a tracing similar to a surface ECG lead, with better visualization of the atrial activity. It is automatically recorded in the event of tachycardia (optionally complemented by the TVI tracing) to discriminate ventricular and supraventricular tachyarrhythmias, haemodynamically tolerated or not. The iECG ventricular complex morphology is unchanged in SVTs. TVI fluctuation shows reduced amplitude, but is regularly present at every beat. The iECG ventricular complex morphology is radically changed in VTs. The example shows a non-tolerated, spontaneously terminated VT. TVI fluctuation is abolished in the absence of ejection and is detected again as soon as sinus rhythm is reestablished. Ventricular pacing reduction (VPR) with full respect of the haemodynamic constraints The pacemakers of the IRIS family are designed to keep the incidence of ventricular pacing at the lowest possible limit still compatible with the haemodynamic efficiency. The stimulation could be avoided also on 2nd degree blocks which maintain the conduction ratio within the programmed limit value.