Temperature-controlled cooled-tip radiofrequency ablation in left ventricular myocardium

Area of Science:

• Cardiovascular Interventions
• Electrophysiology
• Medical Device Technology

Background:

• Radiofrequency catheter ablation (RFCA) can cause steam pops and intramural charring.
• Cooled-tip catheters aim to mitigate these risks.
• Feasibility of temperature-controlled RFCA requires further investigation.

Purpose of the Study:

• To assess the feasibility of temperature-controlled cooled-tip RFCA in a canine heart model.
• To evaluate the safety and efficacy of this technique in preventing adverse thermal events.

Main Methods:

• An internally cooled ablation catheter was used in conjunction with a custom RF generator.
• Temperature control was achieved by slowly increasing RF power to a preset tip temperature of 40°C for 90 seconds.
• Acute intramyocardial temperature measurements and chronic lesion assessment (depth and volume) were performed in canine subjects.

Main Results:

• No steam pops or abrupt impedance rises were observed during acute studies.
• Maximum intramyocardial temperature reached 72.4 ± 14.4°C, with no coagulum, craters, or charring.
• Chronic studies showed lesion depths of 5.9 ± 1.1 mm and volumes of 281 ± 210 mm³.

Conclusions:

• Temperature-controlled RFCA with a cooled-tip catheter is feasible.
• This technique effectively prevents adverse thermal events like steam pops and charring.
• The study demonstrates a potentially safer approach to RF catheter ablation.