Closed-chest electrode-catheter technique for His bundle ablation in dogs

Abstract

A modified quadripolar electrode catheter that had two-thirds of the distal surface insulated with high-voltage plastic was inserted in 10 dogs. After a His bundle potential had been recorded, a synchronized direct-current electrical discharge was delivered between the electrodes showing the largest His bundle deflection using a standard direct-current defibrillator, and a metallic plate was positioned over the dog's back. Complete atrioventricular (AV) block was induced in 9 of 10 dogs, which were followed for 3 mo before being killed. During AV block, the QRS complex was broad and not preceded by a His bundle deflection. The mean control cycle length during AV block was 1,441 +/- 223 ms and decreased to 1,151 +/- 181 ms after exercise, a response that was usually abolished by beta-blockade. Overdrive pacing resulted in pacemaker suppression with gradual rate stabilization after 10-20 beats. There was no evidence of myocardial or valvular damage. This technique provides for a stable model of complete AV block and is suitable for experiments in which heart rate control is required. In addition, this technique may be of value for patients with tachycardia requiring His bundle section.

Innovations in Clinical Cardiac Electrophysiology: Challenges and Upcoming Solutions in 2018 and Beyond

“…In comparison with prior irreversible treatments such as alcohol injection and surgical transection, cryothermal energy offered the major advantage of the ability to identify the appropriate target area and observe for functional effect following the application of cryothermal energy prior to production of an irreversible lesion. Initially, all approaches were surgical in nature, until a ''closed chest'' 35,36 was developed, which is known today as the transvenous approach. Initial practice with the closed chest approach deviated away from the use of cryothermal energy and instead employed direct current (DC) energy [37][38][39] and laser.…”

“…Initially, all approaches were surgical in nature, until a ''closed chest'' 35,36 was developed, which is known today as the transvenous approach. Initial practice with the closed chest approach deviated away from the use of cryothermal energy and instead employed direct current (DC) energy [37][38][39] and laser. 40 Results were largely encouraging; however, complications from these approaches, namely barotrauma and perforation, respectively, lead to the study and application of radiofrequency (RF) energy.…”

What Have We Learned About Cardiac Arrhythmias?

“…In the early 1980s, Scheinman (Gonzalez et al 44 ) and Gallagher et al 45 demonstrated that a high-energy shock delivered over a catheter placed against the bundle of His could interrupt AV conduction to create chronic, complete AV block. Although this treatment had a relatively restricted application for patients with atrial arrhythmias, such as atrial fibrillation with an uncontrolled rapid ventricular rate, it introduced the concept of being able to alter the electrophysiology of the heart with a catheter.…”

Low-energy transvenous ablation of the canine atrioventricular conduction system with a suction electrode catheter.

“…Herein we report the short-and long-term electrophysiologic effects of low-energy (<30 J) direct-current shocks for ablation of the canine AV conduction system with a suction electrode catheter and correlate these with the histologic changes in the AV conduction system. FIGURE 1. A, The suction ablation catheter has a central lumen with a suction port and two electrodes.…”