Efficacy of two commercially available cardiac pacing catheters for transesophageal atrial pacing in dogs

Abstract

Objective Compare the efficacy of two cardiac pacing catheters for transesophageal atrial pacing (TAP). Animals Ten healthy dogs. Methods Transesophageal atrial pacing was attempted in left lateral recumbency under general anesthesia. In series, a curved electrophysiologic (EP) catheter and a straight transesophageal pacing (TP) catheter were passed transorally into the distal esophagus, caudal to the heart. Each catheter was slowly withdrawn until pacing was initiated. The catheter continued to be withdrawn in 5 mm increments until capture was no longer achieved at maximal pacing setting creating a total zone of capture (tZOC). Minimum pacing threshold (Thmin) and degree of extraneous muscle stimulation (EMS) were determined at each site. Results The EP catheter achieved TAP in 10/10 dogs with a Thmin of 8.8 ± 4.8 mA and tZOC of 4.0 ± 1.7 cm. The TP catheter achieved TAP in 7/10 dogs with a Thmin of 22.5 ± 5.6 mA and tZOC of 1.2 ± 1.6 cm. No EMS was noted during TAP at Thmin using the EP catheter. Of the 7 dogs in which TAP was successful, 3/7 experienced considerable EMS at Thmin. There was no significant relationship between patient body weight and Thmin with either catheter (EP catheter P= 0.09; TP catheter P= 0.81) Conclusions The electrophysiology catheter captured the atria of more dogs over a larger area without EMS as compared to the TP catheter. The electrophysiology catheter is recommended for transesophageal atrial pacing in dogs.

Temporary Cardiac Pacing

“…The main advantages of the transvenous system are more consistent capture in patients with either sinus nodal or atrioventricular (AV) nodal disease, improved patient comfort allowing its use in sedated or awake patients, lower cost of equipment, and relative ease of insertion by experienced personnel. 10,11 The pacing catheter, either a specialized transesophageal pacing lead or a multipurpose electrophysiologic catheter, is inserted into the esophagus just dorsal to the heart. Other complications include thrombosis, bleeding, infection, ventricular arrhythmias, and cardiac perforation.…”

“…This pacing system is expensive and is available only at a few veterinary institutions. 11 As with all the other pacing systems, electrocardiography (and optionally fluoroscopy) is used to guide pacing catheter placement and identify atrial capture. 8,9,16,17 Standard ECG leads usually are connected to the dog's footpads to obtain a good-quality recording.…”

“…10,11,19 The equipment needed for transesophageal pacing includes a specialized transesophageal pulse generator, a bipolar pacing catheter, and a semirigid plastic guide (optional). Only a few veterinary centers have this capability, but it offers an attractive noninvasive alternative for heart rate support in animals with sinus nodal dysfunction undergoing general anesthesia.…”

Effect of pulse width on transesophageal atrial pacing in dogs

“…; Sanders et al. ; Chapel & Sanders ). Further studies and a clinical case report have described the use of TAP in which the catheter was successfully placed without the use of fluoroscopic guidance (Sanders et al.…”

“…Two previous studies involving atrial pacing in multiple dogs assessed pulse durations of 2.0 and 10.0 ms (Sanders et al. ; Chapel & Sanders ). In each case, TAP was successful without significant EMS, but PT, defined as the lowest level of pacing stimulus that results in successful pacing, was lower using the 10.0 ms PW (8.8 ± 4.8 mA versus 10.5 ± 3.9 mA) (Sanders et al.…”