Determinants of Lesion Sizes and Tissue Temperatures During Catheter Cryoablation

Abstract

Lesion sizes and tissue temperatures during catheter cryoablation are related to convective warming, electrode orientation, electrode contact pressure, and any of the following: electrode size, catheter refrigerant flow rate or electrode temperature. However, electrode temperature may be a poor predictor of lesion size and tissue temperature for a given catheter size.

Biomarkers of myocardial injury with different energy sources for atrial fibrillation catheter ablation

“…RF ablation of more myocardial tissue in the atria, such as in PV isolation, is expected to have much higher cTn levels [10][11][12][20][21][22][23][24][25]. Previous clinical studies reported contrasting data, in the setting of AF ablation, on cardiac biomarkers levels after cryoballoon ablation compared to RF ablation [7,[13][14][15][16][17][18][19]26]. Kuhne et al [7] reported higher post procedural cTnT levels in RF group vs. cryoballoon group.…”

“…First studies focused on RF lesion and it has been demonstrated that cTnI and cTnT are more sensitive and specific than CK--MB for the diagnosis of myocardial injury after RF ablation [5,6]. It has also been showed that the rise of biomarkers and the extent of myocardial damage after RF catheter ablation depend on the number of RF pulses and site of ablation [12][13][14][15][16]19]. A lower cTn level is expected after RF of focal area with few RF lesions.…”

“…As several markers have been proven to be useful for diagnosis and evaluation of size of myocardial injury after acute ischemic episode, many authors tried to implement different biomarkers to evaluate and quantify the size of effective ablation lesions [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. On one hand, previous studies have univocally shown humoral biomarkers for myocardial injury to be elevated after radiofrequency (RF) ablation, depending on the amount of energy delivered and the site of ablation [5].…”

Another Tool for the Ablation Toolbox

“…It would be expected that the 6 mm tip or the 8 mm tip cryoablation catheter would create larger lesion dimensions. Also, there are far more combinations of variables that could potentially be evaluated, including higher power and temperatures for radiofequency ablations, longer duration of either cryoablation or radiofrequency lesions, catheter tip orientation, time to cool the cryoablation electrode or time to cryoablation electrode rewarming 36,37 …”

Comparison of Endocardial and Epicardial Lesion Size Following Large-Tip and Extra-Large-Tip Transcatheter Cryoablation

“…23 Wood et al performed in-vitro experiments with 7F, 4-mm and 9F, 8-mm tip catheters and found that cryoablation lesion sizes and tissue temperatures are related to convective warming, electrode orientation, electrode contact pressure, and any of the following: electrode size, catheter refrigerant flow rate, and electrode temperature. 24 d'Avila et al reported that endocardial and epicardial cryolesions created in a normal caprine model by focal cryoablation for 4 min with a 7F, 6-mm tip catheter at a mean temperature of -77±2°C for endocardium and -81± 3°C for epicardium were similar in size and depth (endocardium: 9.7±0.4 mm long, 7.3±1.4 mm wide, 4.8±0.2 mm deep; epicardium: 10.2±1.4 mm long, 7.7±2.0 mm wide, 4.6±0.9 mm deep). 25 They also reported that the epicardial cryolesion created in a porcine chronic infarct model by linear cryoablation with a 7F, 30-mm tip catheter at a mean temperature of -84±6°C for 4 min was 36.5±7.8 mm long, 8.2±1.3 mm wide, and 6.0±1.2 mm deep.…”