Impact of Lowering Irrigation Flow Rate on Atrial Lesion Formation in Thin Atrial Tissue

Abstract

Low-flow irrigated ablation provides favorable lesion characteristics for posterior LA ablation without increasing the risk of adverse events.

‘CLOSE’-Guided Pulmonary Vein Isolation and Changes in Local Bipolar and Unipolar Atrial Electrograms:Observations from the EP Lab

“…Also the use of large tip electrodes might result in farfield sensing. More recently, Kumar et al showed that the actual incidence of voltage attenuation or loss of unipolar R wave was clearly dependent on the irrigation rate (with a very low incidence in high flow ablation like in the present study) [23] . (4) Finally, in the clinical setting -in contrast to experimental models -variables like catheter orientation, microshifting of the ablation catheter tip, complex architecture (ridges, crypts and valleys), tissue thickness and composition come into play.…”

Prevention and Treatment of Atrioesophageal Fistula Related to Catheter Ablation for Atrial Fibrillation

“…2 As opposed to nonirrigated ablation, irrigating the catheter tip with open saline flow to cool the interface has been shown to prevent coagulum formation, reduce the risk of emboli, and enable formation of deeper lesions in the LA wall. 20 However, irrigating with a lower flow rate (2 mL/min versus 17 mL/min) has been shown to maximize the endocardial lesion diameter while also allowing for reduced deep tissue heating. 20 Recently, high-power, short-duration irrigated lesions utilizing primarily resistive heating have been described as another alternative to standard ablation techniques, which rely on both resistive and conductive heating for lesion formation.…”

“…20 However, irrigating with a lower flow rate (2 mL/min versus 17 mL/min) has been shown to maximize the endocardial lesion diameter while also allowing for reduced deep tissue heating. 20 Recently, high-power, short-duration irrigated lesions utilizing primarily resistive heating have been described as another alternative to standard ablation techniques, which rely on both resistive and conductive heating for lesion formation. 21 Leshem et al demonstrated in a swine model that ablation with the QDOT-Micro catheter (Biosense-Webster, Diamond Bar, CA, USA) at 90 W for four seconds resulted in contiguous transmural lines, as compared with 25 W for 20 seconds, which resulted in gaps and nontransmurality.…”

Oesophageal Injury During AF Ablation: Techniques for Prevention

“…38,40 Open irrigation is associated with deeper and larger lesions, as irrigated catheters minimise the risk of thrombus formation by cooling the catheter surface, thus allowing the use of higher power settings and longer durations. 41 In an experimental clinical study by Kumar et al, 43 catheter ablation. 44 In 9 of the 12 patients, this was a redo procedure the oesophagus, which could lead to inadvertent injury.…”