New cardiomechanic pacing lead sensor based on high frequency parameters: experimental studies in sheep

Area of Science:

• Cardiovascular Electrophysiology
• Biomedical Engineering
• Hemodynamics

Background:

• Myocardial contraction generates mechanical signals detectable by implanted cardiac pacing leads.
• High-frequency (HF) parameters from bipolar pacing leads can be leveraged to measure these cardiomechanic signals.

Purpose of the Study:

• To investigate the potential of using HF parameters from pacing leads as a cardiomechanic sensor.
• To quantify ventricular contraction by measuring the lead-bending signal (LBS) and lead-bending acceleration (LBA).

Main Methods:

• Implantation of three different pacing leads in nine sheep.
• Measurement of LBS and LBA under baseline and induced hemodynamic conditions (dobutamine infusion, VVI pacing at 200 bpm).
• Correlation analysis between LBA and left ventricular dP/dt (LV dP/dt).

Main Results:

• Stable, reproducible LBS signals were obtained across various experimental conditions and up to 4 months post-implantation.
• A statistically significant correlation (r = 0.855, P <0.001) was found between LBAmax and LV dP/dtmax.
• Hemodynamic deterioration during fast ventricular pacing was reflected by decreased LV dp/dt and LBA.

Conclusions:

• The feasibility and efficacy of using HF lead parameters as a hemodynamic sensor are confirmed.
• Lead-bending acceleration (LBAmax) is highly correlated with ventricular contractility.
• This technology can be efficiently utilized as a hemodynamic and cardiomechanic sensor in implantable cardiac electrotherapy devices.