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Electrophysiological studies on cardiac catheter ablation
E N Moore1, W Schafer, A Kadish
1Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia.
Pacing and Clinical Electrophysiology : PACE
|January 1, 1989
Summary
High energy shocks during cardiac ablation can cause arrhythmias. Researchers found that electrical current density and proximity to the electrode significantly impact tissue damage and cellular function, potentially explaining variable ablation outcomes.
Area of Science:
- Cardiovascular Electrophysiology
- Medical Device Technology
- Cardiac Ablation
Background:
- High energy electrical shocks are linked to cardiac arrhythmias and variable success in catheter ablation.
- Understanding electrode configuration and location effects on electrograms is crucial for improving ablation outcomes.
Purpose of the Study:
- To investigate the cellular effects of catheter ablation shocks and argon laser photoablation on cardiac tissue.
- To correlate shock parameters with observed cellular changes and potential mechanisms for arrhythmias post-ablation.
Main Methods:
- Analysis of cellular effects of catheter ablation shocks and argon laser photoablation using microelectrodes.
- Investigation of low-energy shock effects (1-10 joules) on cardiac tissue membrane potential and conduction.
- Assessment of electrode configuration and location impact on electrogram size.
Main Results:
- Catheter ablation shocks caused depression of resting potential, action potential amplitude, dV/dt, and duration, with damage most severe between electrodes and nearest the cathode.
- Argon laser photoablation resulted in a more focal injury with a smaller border zone.
- Low-energy shocks induced a 'membrane hang-up' phenomenon, altering conduction and correlating with shock intensity and duration; sequential shocks had additive effects.
Conclusions:
- Electrical current density and proximity to electrodes are critical factors in catheter ablation-induced tissue damage.
- The 'membrane hang-up' phenomenon observed with low-energy shocks may contribute to transient arrhythmias following ablation.
- Findings provide insights into optimizing catheter ablation techniques and managing post-ablation complications.