Effect of Baseline Impedance in Radiofrequency Delivery on Lesion Characteristics and the Relationship Between Impedance and Steam Pops

• Published in: Frontiers in cardiovascular medicine 2022-04, Vol.9, p.872961-872961
• Main Authors: Qu, Lijuan, Guo, Min, Sun, Meng, Wang, Rui, Zhang, Nan, Li, Xin
• Format: Article
• Language: English
• Subjects: Cardiovascular Medicine; impedance; lesion characteristics; radiofrequency ablation; steam pop
• ISSN: 2297-055X; 2297-055X
• DOI: 10.3389/fcvm.2022.872961

To explore the effects of baseline impedance (R) and power (P) on radiofrequency ablation (RFA) lesion characteristics and their correlation with steam pops using ThermoCool SmartTouch-SF (STSF) catheters in the porcine heart. A porcine left ventricle was submerged in 37°C saline , and the experiment was performed with various ( = 30, 40, 50, and 60 W) and multiple loads ( = 80-100, 100-140, 140-180, and 180-220 Ω) to reach the target ablation index (AI; AI = 350, 450, and 500) or reach the target ablation time using a fixed contact force (CF; CF = 10-15 g) and the same saline irrigation (30 W/8 ml/min or 40-60 W/15 ml/min), repeated five times under each condition. The surface diameter, maximum diameter, depth, and volume of the lesions were strongly correlated with the AI ( = 40 W, = 100-140 Ω, CF = 10-15 g) ( = 0.5412; = 0.7889; = 0.9366; and = 0.913, respectively; all < 0.05). As the value of increased, the maximum diameter, depth, and volume of the lesions significantly increased (AI = 350, = 30 W). Moreover, the higher the baseline value of , the greater the absolute value of the decrease ( = 0.9035, < 0.05, = 0.2759 × - 18.33). Under high power and high impedance, the occurrence rate of steam pops was high ( = 60 W, = 180-220 Ω, AI when a steam pop occurred: 480 ± 26.5, ablation time: 11.29 ± 1.04 s). Radiofrequency catheter ablation (RFCA) in power-controlled mode resulted in various lesion characteristics that were related to diverse baseline Rs. In addition, the incidence of steam pops was strongly correlated with high baseline and high .