A new orthogonal lead for P synchronous pacing

Area of Science:

• Cardiology
• Biomedical Engineering
• Electrophysiology

Background:

• P synchronous pacing is beneficial for patients with atrioventricular conduction defects.
• Existing endocavitary systems often suffer from unreliable P wave sensing or require extra leads.

Purpose of the Study:

• To develop and evaluate a novel single-lead system for P synchronous pacing.
• To assess the efficacy of orthogonal P wave sensing in a unipolar ventricular lead.

Main Methods:

• A single endocardial lead with a unipolar ventricular electrode and orthogonal P wave sensing was designed.
• The lead featured circumferentially placed atrial sensing electrodes near the catheter tip.
• The system was tested in 22 patients undergoing electrophysiologic study or pacemaker implantation.

Main Results:

• The system recorded significant atrial electrogram voltages (2.47 mV in X axis, 2.32 mV in Y axis).
• Excellent discrimination between P waves and QRS complexes was achieved (P/QRS ratio of 32/1).
• No adverse effects on QRS morphology or ventricular pacing were observed.

Conclusions:

• A single catheter with integrated atrial sensing electrodes can achieve effective P synchronous pacing.
• The novel design provides robust atrial sensing with superior QRS signal rejection.
• This technology represents a significant advancement for pacing in patients with intact sinus node function.