Optimizing atrio-ventricular delay in pacemakers using potentially implantable physiological biomarkers.

Area of Science:

• Cardiovascular physiology
• Medical device technology
• Biomedical engineering

Background:

• Optimizing atrioventricular (AV) delay is crucial for hemodynamic function.
• Current methods like echocardiography or blood pressure (BP) monitoring are labor-intensive.
• Laser Doppler perfusion monitoring offers a potential non-invasive approach for assessing blood flow.

Purpose of the Study:

• To evaluate the efficacy of Laser Doppler perfusion monitoring as a substitute for beat-by-beat blood pressure measurements in optimizing AV delay.
• To assess the feasibility of integrating Laser Doppler into future implantable cardiac devices for dynamic AV delay optimization.

Main Methods:

• Ninety-four AV delay optimizations were performed on 58 patients using biventricular or His-bundle pacing.
• Laser Doppler and simultaneous noninvasive beat-by-beat BP measurements were utilized.
• Hemodynamic response curves were analyzed to determine optimal AV delay, with automatic quality control.

Main Results:

• 55/94 optimizations met quality control standards, yielding optimal AV delays comparable to BP-derived values (median absolute deviation 12 ms).
• Increasing the number of replicates in the extended protocol consistently improved optimization quality and reduced disagreement between Laser Doppler and BP.
• With 50 replicates, all optimizations passed quality control, achieving a median absolute deviation of 13 ms.

Conclusions:

• Laser Doppler perfusion monitoring provides equivalent hemodynamic optima for AV delay compared to BP measurements.
• Automated quality control and increased replicates enhance the reliability of Laser Doppler-based optimization.
• This technique holds promise for dynamic and reliable AV delay optimization in future implantable cardiac devices.