Radiofrequency ablation lesions were significantly smaller in intermediate- and low-voltage myocardium compared with normal-voltage myocardium (P<0.001).
Does radiofrequency ablation produce different lesion sizes in low, intermediate, and normal-voltage myocardium in a post-MI porcine model?
Radiofrequency ablation lesions are smaller in low- and intermediate-voltage infarcted myocardium compared to normal myocardium despite similar ablation parameters.
p-value: p=<0.001
AIMS: Contact force (CF) between radiofrequency (RF) ablation catheter and myocardium and ablation index (AI) correlates with RF lesion depth and width in normal-voltage (>1.5 mV) myocardium (NVM). We investigate the impact of CF on RF lesion depth and width in low (<0.5 mV) (LVM) and intermediate-voltage (0.5-1.5 mV) myocardium (IVM) following myocardial infarction. Correlation between RF lesion depth and width evaluated by native contrast magnetic resonance imaging (ncMRI) and gross anatomical evaluation was investigated. METHODS AND RESULTS: Twelve weeks after myocardial infarction, 10 pigs underwent electroanatomical mapping and endocardial RF ablations were deployed in NVM, IVM, and LVM myocardium. In vivo ncMRI was performed before the heart was excised and subjected to gross anatomical evaluation. Ninety (82%) RF lesions were evaluated. Radiofrequency lesion depth and width were smaller in IVM and LVM compared with NVM (P < 0.001). Radiofrequency lesion depth and width correlated with CF, AI, and impedance drop in NVM (CF and AI P < 0.001) and IVM (CF and AI depths P < 0.001; CF and AI widths P < 0.05). Native contrast magnetic resonance imaging evaluated RF lesion depth and width correlated with gross anatomical depth and width (NVM and IVM P < 0.001; LVM P < 0.05). CONCLUSIONS: Radiofrequency lesions deployed by similar duration, power and CF are smaller in IVM and LVM than in NVM. Radiofrequency lesion depth and width correlated with CF, AI, and impedance drop in NVM and IVM but not in LVM. Native contrast magnetic resonance imaging may be useful to assess RF lesion depth and width in NVM, IVM, and LVM.
Tofig et al. (Thu,) conducted a other in Myocardial infarction (n=10). Radiofrequency ablation vs. Normal-voltage myocardium was evaluated on Radiofrequency lesion depth and width (p=<0.001). Radiofrequency ablation lesions were significantly smaller in intermediate- and low-voltage myocardium compared with normal-voltage myocardium (P<0.001).