Atrial septal pacing in small dogs: a pilot study.

Area of Science:

• Veterinary Cardiology
• Biomedical Engineering
• Animal Models in Research

Background:

• Atrial septal pacing is a potential treatment for sinus node dysfunction in dogs.
• Small breed dogs are particularly prone to sinus node dysfunction.
• Evaluating novel pacing leads and techniques is crucial for improving canine cardiac care.

Purpose of the Study:

• To assess the feasibility of atrial septal pacing using a specific catheter-guided pacing lead in dogs.
• To evaluate the stability and performance of the pacing lead in the canine atrial septum.
• To identify potential challenges and reasons for lead instability during atrial pacing.

Main Methods:

• Six healthy beagles underwent implantation of a Medtronic 3830 SelectSecure lead via a Medtronic Attain Select II catheter.
• Pacing threshold, lead impedance, and Wenckebach point were measured.
• Thoracic radiographs were used to assess lead position at multiple time points post-implantation.

Main Results:

• Macro-lead dislodgement occurred in 5 out of 6 dogs within one month.
• Lead impedance varied between 583 and 1421 Ω at implantation.
• Wenckebach points were >220 ppm in four dogs, but lower in two dogs (120 and 190 ppm).

Conclusions:

• The tested implantation technique and lead system were inadequate for secure atrial septal lead placement in dogs.
• Potential causes for instability include lead design, insufficient slack, and improper seating.
• Further investigation into alternative techniques and leads is necessary for effective atrial pacing in susceptible canine populations.