Radiofrequency multielectrode catheter ablation in the atrium

Area of Science:

• Medical Devices
• Biomedical Engineering
• Electrophysiology

Background:

• Radiofrequency (RF) ablation is a common therapeutic procedure.
• Achieving contiguous and transmural lesions is crucial for effective ablation.
• Existing systems may have limitations in controlling lesion size and contiguity.

Purpose of the Study:

• To develop and evaluate a novel temperature-controlled RF system for simultaneous ablation using multiple electrodes.
• To assess the system's ability to create long, contiguous, and potentially therapeutic lesions.
• To analyze the performance and safety of the system in vitro and in vivo.

Main Methods:

• A temperature-controlled RF generator with a microcontroller and electronic switches was developed.
• The system delivered energy to up to six 12.5 mm coil electrodes simultaneously.
• Temperature feedback was obtained from sensors at each electrode, regulating power to maintain a set temperature within a 5°C interval.
• Finite element models and current density measurements were used for physical analysis.
• Performance was evaluated in vitro and in vivo (canine right atria).

Main Results:

• In vitro studies showed that 85-100% of lesions were contiguous at set temperatures of 70-90°C.
• Lesion length increased linearly with the number of electrodes used.
• In vivo, contiguous lesions were created in canine right atria with 75% being potentially therapeutic (transmural and covering the target region).
• No sudden impedance rises occurred during in vivo procedures.
• Average procedure and fluoroscopy times were 83.4 and 5.9 minutes, respectively.

Conclusions:

• The developed temperature-controlled RF system can safely create long and contiguous lesions.
• The system demonstrates promising results for therapeutic ablation, particularly in cardiac applications.
• Simultaneous multi-electrode ablation with precise temperature control enhances lesion efficacy and safety.