Arrhythmias & electrophysiology
Radiofrequency Ablation of the Diseased Human Left Ventricle: Biophysical and Electrogram-Based Analysis
Authors' conclusion
On biophysical analysis, ablation beyond an AI of 763 and FTI of 713 gs offers minimal additional efficacy on average. Fibrosis blunts ablation efficacy. AI is a stronger correlate with impedance drop than FTI. EGM attenuation does not correlate with ablation parameters.
Study context
- Population
- Patients undergoing VT ablation402 ablations analysed
- Participants
- 15 patients
- Comparison
- Normal-voltage myocardium (NVM) vs intermediate-voltage myocardium (IVM) vs low-voltage myocardium (LVM)
- Outcome
- Relationships of ablation index (AI) and force-time integral (FTI) with impedance drop and EGM attenuation in the human LV
Main finding
As reported in the abstract
| Group | Repeated-measures correlation, ablation index (AI) vs impedance drop | Repeated-measures correlation, force-time integral (FTI) vs impedance drop |
|---|---|---|
| NVM | 0.67 | 0.59 |
| IVM | 0.60 | 0.51 |
| LVM | 0.52 | 0.42 |
Repeated-measures correlation, ablation index (AI) vs impedance drop
NVM0.67
IVM0.60
LVM0.52
Repeated-measures correlation, force-time integral (FTI) vs impedance drop
NVM0.59
IVM0.51
LVM0.42
- % impedance drop correlated with AI (repeated-measures correlation coefficient)
- 0.54
- % impedance drop correlated with FTI (repeated-measures correlation coefficient)
- 0.44
- Correlation of impedance drop with AI and FTI
- P < 0.0005
- Curve plateau: AI
- 763
- Curve plateau: FTI
- 713 gram-seconds
- Impedance drop at plateau
- 7.5%
- Shallower curves progressively from NVM to LVM
- P < 0.0005
- Mixed models: standardized β for AI on impedance drop (greater than fibrosis, drift, orientation)
- 0.54
- Mixed models: standardized β for FTI on impedance drop
- 0.48
Further findings
Electrogram (EGM) attenuation with ablation
- EGM attenuation (median)
- 29.3%; IQR: 4.4%-53.3%; P < 0.0005
- Attenuation did not correlate with AI or FTI
Original publication
Radiofrequency Ablation of the Diseased Human Left Ventricle: Biophysical and Electrogram-Based Analysis. JACC Clin Electrophysiol. Published 10 October 2022. doi:10.
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