EP radiofrequency generators: Significant offsets between selected and delivered power?

Area of Science:

• Electrophysiology
• Medical Device Engineering

Background:

• Radiofrequency (RF) ablation is a common medical procedure.
• EP Shuttle, Ampere, and SmartAblate are frequently used RF generators in clinical practice.

Purpose of the Study:

• To assess the correlation between selected and delivered RF power for different generator models.
• To evaluate the impact of power discrepancies on ablation lesion size.

Main Methods:

• Experimental setup measuring delivered RF power from EP Shuttle, Ampere, and SmartAblate generators.
• Comparison of selected vs. delivered power across varying impedance levels (n=800 measurements).
• Ex vivo porcine cardiac muscle ablation lesion analysis (n=80).

Main Results:

• EP Shuttle generator showed significant power offsets, delivering up to 40% more power than selected, especially at higher impedances.
• At 200 Ω and 30 W selected power, EP Shuttle delivered 40.3 W, Ampere 30.1 W, and SmartAblate 28.1 W.
• Higher impedance with EP Shuttle resulted in significantly larger ablation lesions.
• Ampere and SmartAblate generators demonstrated accurate power delivery with no significant offsets.

Conclusions:

• Ampere and SmartAblate generators ensure accurate power delivery, crucial for predictable ablation outcomes.
• The EP Shuttle generator's tendency to exceed selected power requires careful consideration in clinical practice to avoid unintended tissue damage.
• Discrepancies in RF power delivery can significantly influence ablation lesion characteristics.