What question did this study set out to answer?

To determine whether controlled cryosurgery applied to the AV node-His bundle region can achieve a therapeutic negative dromotropic effect without causing complete atrioventricular block.

September 1, 1985Pacing and Clinical Electrophysiology

Controlled Cryothermal Injury to the AV Node: Feasibility for AV Nodal Modification

View Full Paper

Ask AI

Bookmark

Population

12 anesthetized dogs

Design

Preclinical

Follow-up

1 month

Authors

GKGeorge J. KleinElectrophysiology GGG GuiraudonElectrophysiology DPD. Garth PerkinsWestern University

Discussion

Member takes

Implication

Cryoablation may enable selective AV nodal modification in patients; leaves open translation from canine models to clinical trials.

Key Points

To determine whether controlled cryosurgery applied to the AV node-His bundle region can achieve a therapeutic negative dromotropic effect without causing complete atrioventricular block.
Twelve anesthetized dogs underwent a right thoracotomy and cardiac inflow occlusion to apply a 15 mm circular cryoprobe directly over the AV node-His bundle region.
Single freeze applications were administered across varied temperatures (-15°C to -60°C) and durations (15 to 60 seconds), with electrophysiological testing repeated after a one-month recovery period prior to sacrifice.
Freezing at -60°C for 15 to 60 seconds caused complete heart block with dense local fibrosis in 5 of 6 dogs.
Warmer freezing temperatures preserved AV conduction in all 7 remaining dogs, with 5 demonstrating AH interval prolongation and 3 of those 5 showing marked prolongation of the Wenckebach cycle length.

Structured PICO

Population

12 anesthetized dogs

Intervention

Cryosurgery to the AV nodal region using a 15 mm circular cryoprobe applied directly to the AV node-His bundle region (single freeze, -15 to -60 degrees C, 15 to 60 seconds)

Outcome

Electrophysiological effects including conduction intervals, incremental pacing, extrastimulus testing, and occurrence of complete heart blocksurrogate

Controlled cryothermal injury to the AV node can create a negative dromotropic response without complete AV block, suggesting feasibility for AV nodal modification.

Cite This Study

Klein et al. (1985) studied this question.

synapsesocial.com/papers/6a714ff42163a0a01bc57712 https://doi.org/10.1111/j.1540-8159.1985.tb05874.x

View Full Paper

Ask AI

Bookmark

Controlled Cryothermal Injury to the AV Node: Feasibility for AV Nodal Modification

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Controlled Cryothermal Injury to the AV Node: Feasibility for AV Nodal Modification

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider