1. Introduction
Radiofrequency catheter ablation (RFCA) for symptomatic atrial
fibrillation (AF) is an established treatment which is associated with
significantly improved quality of
life.1 Recent clinical
trials also suggest that RFCA can improve not only quality of life but
also hard clinical outcomes including all cause death in patients with
both AF and heart
failure.2,
3 Claim data based retrospective data
also suggest that RFCA is associated with reduced risk of ischemic
stroke.4,
5 Despite various benefits of RFCA in AF
patients, RFCA is associated with several catastrophic complications
such as procedure-related stroke or atrio-esophageal
fistula.6
Time interval between occurrence of procedure-related stroke and correct
diagnosis due to patient sedation delays appropriate therapy and
significant proportion of patients with procedure-related stroke have
permanent neurologic consequences. Optimal treatment modalities for
procedure-related stroke are also not established since majority of
these strokes are due to char formation during radiofrequency energy
delivery.7,
8 Char formation during radiofrequency
energy delivery is thought to be related with tissue overheating and
acute cellular damage.9Irrigation catheters were developed in order to reduce tissue
overheating and char
formation.10-12 Among
irrigation catheters, open-irrigation catheters showed lower interface
temperature, thrombus, and steam pop compared with closed-loop
irrigation catheters indicating greater interface cooling
capability.13Open-irrigation catheters are further classified according to their
shape: 6-holes, 12-holes, 56-holes, and slit-based irrigation system.
Slit-based irrigation catheters have the largest irrigation space
compared to other open-irrigation catheters. However, whether slit-based
irrigation catheters are superior to other open-irrigation catheters in
terms of stroke prevention remains largely unknown. We aimed to compare
the risk of procedure-related ischemic complication among
non-irrigation, non-slit-based irrigation, and slit-based irrigation
catheters.