Hemodynamic Surveillance of Ventricular Pacing Effectiveness with the Transvalvular Impedance Sensor

Abstract EN

The Transvalvular Impedance (TVI) is derived between atrial and ventricular pacing electrodes.

A sharp TVI increase in systole is an ejection marker, allowing the hemodynamic surveillance of ventricular stimulation effectiveness in pacemaker patients.

At routine follow-up checks, the ventricular threshold test was managed by the stimulator with the supervision of a physician, who monitored the surface ECG.

When the energy scan resulted in capture loss, the TVI system must detect the failure and increase the output voltage.

A TVI signal suitable to this purpose was present in 85% of the tested patients.

A total of 230 capture failures, induced in 115 patients in both supine and sitting upright positions, were all promptly recognized by real-time TVI analysis (100% sensitivity).

The procedure was never interrupted by the physician, as the automatic energy regulation ensured full patient’s safety.

The pulse energy was then set at 4 times the threshold to test the alarm specificity during daily activity (sitting, standing up, and walking).

The median prevalence of false alarms was 0.336%.

The study shows that TVI-based ejection assessment is a valuable approach to the verification of pacing reliability and the autoregulation of ventricular stimulation energy.