#IssaTweetorials
#EPeeps
Impedance and RF ablation:
Part 2: How does RF ablation affect impedance?
1/9
As tissue temperature rises during RF energy application, ions within the tissue being heated become more mobile, resulting in a decrease in impedance to current flow.
#EPeeps
Impedance and RF ablation:
Part 2: How does RF ablation affect impedance?
1/9
As tissue temperature rises during RF energy application, ions within the tissue being heated become more mobile, resulting in a decrease in impedance to current flow.
2/9
There are currently 2 methods to measure impedance: Generator Impedance (GI) & Local Impedance (LI).
There are currently 2 methods to measure impedance: Generator Impedance (GI) & Local Impedance (LI).
3/9
Lack of impedance drop during RF energy application can reflect inefficient energy delivery to the tissue due to poor tissue contact, lack of catheter stability, or inadequate power delivery.
Lack of impedance drop during RF energy application can reflect inefficient energy delivery to the tissue due to poor tissue contact, lack of catheter stability, or inadequate power delivery.
4/9
LI is measured at the distal electrode of the catheter and represents near-field impedance at the ablation electrode-tissue interface.
LI is measured at the distal electrode of the catheter and represents near-field impedance at the ablation electrode-tissue interface.
5/9
LI drop rate and the magnitude of drop closely correlate to the intra-mural tissue temperature (2-4 mm below the tissue surface) during standard and high-power RF ablation and can thereby act as an intramural thermometer.
LI drop rate and the magnitude of drop closely correlate to the intra-mural tissue temperature (2-4 mm below the tissue surface) during standard and high-power RF ablation and can thereby act as an intramural thermometer.
6/9
LI drop of 10-20-Ω is observed in clinically effective & safe (intramural temperature 55-90°C) RF applications.
Larger LI drops (>35 Ω) often reflect excessive tissue heating (intramural peak temperature nearing 100°C), indicating a risk for steam pops/char formation.
LI drop of 10-20-Ω is observed in clinically effective & safe (intramural temperature 55-90°C) RF applications.
Larger LI drops (>35 Ω) often reflect excessive tissue heating (intramural peak temperature nearing 100°C), indicating a risk for steam pops/char formation.
7/9
LI offers 4-time greater working range than GI, which may permit more precise titration of energy delivery, especially during high-power RF ablation when tissue heating occurs rapidly.
LI offers 4-time greater working range than GI, which may permit more precise titration of energy delivery, especially during high-power RF ablation when tissue heating occurs rapidly.
Compared to GI, LI offers more sensitive & more specific measure of intramural tissue heating, as well as larger and more rapid impedance drops during RF application, allowing LI to be used as a real-time monitor of RF lesion formation & to guide titration of RF energy delivery.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
