Ring Char Formation During High-Power, Short-Duration Ablation Using an Irrigated Six-Hole Contact Force Sensing Tip...

Area of Science:

• Electrophysiology
• Cardiovascular Medicine
• Medical Device Technology

Background:

• Circumferential ablation of pulmonary veins (PVs) is a key procedure in treating atrial fibrillation.
• High-power, short-duration (HPSD) ablation is an advanced technique aiming for efficient lesion creation.
• Potential complications during radiofrequency (RF) ablation, such as impedance changes, require careful monitoring.

Purpose of the Study:

• To report a specific complication encountered during HPSD ablation of the right PVs.
• To describe the characteristics of thrombus formation associated with HPSD ablation.
• To highlight the importance of recognizing impedance changes as a potential indicator of thrombus.

Main Methods:

• Performed circumferential ablation of the right PVs using HPSD energy.
• Monitored impedance changes during RF delivery.
• Visualized catheter tip and surrounding structures after an observed impedance increase.

Main Results:

• An abrupt increase in impedance from 120 to 180 Ω occurred 11 seconds after initiating RF delivery.
• Withdrawal of the ablation catheter revealed a circumferential thrombus adhered to the catheter tip, above the irrigation holes.
• The removed thrombus was ring-shaped, confirming adherence to the catheter tip post-ablation.

Conclusions:

• HPSD ablation, particularly at the anterior wall of the right PVs, carries a risk of catheter tip thrombus formation.
• Abrupt impedance increases during RF ablation can signify the development of thrombus.
• Awareness of this complication is crucial for procedural safety and patient outcomes in PV ablation.