Purerfellner H., Aichinger J., Martinek M., Nesser H.J., Janssen J, 7
“Short- and long-term experience in pulmonary vein segmental ostial ablation for
paroxysmal atrial fibrillation”
Conclusion: The CRR of patients with medical refractory PAF in our patient cohort is 78% at
the 6 month follow up. PV stenosis is the main cause for procedure-related complications.
Ablation of all 4 PV exhibits a tendency towards higher complete success rates despite equal
CRR. Calculation of the clinical response after a mid- to long-term follow of 21±6 months in
those patients with an ostial PVI in only 3 pulmonary veins (sparing the right inferior PV) shows
a further reduction to 62%, exclusively caused by a drop in patients with a former partial
success. To evaluate the long-term clinical benefit of segmental ostial PVI in comparison with
other ablation techniques, more extended follow up periods are mandatory, including a larger
study cohort and a detailed description of procedural parameters.
Keywords: atrial fibrillation; pulmonary vein ablation
Introduction
Based on groundbreaking work by Michel Haissaguerre et al. a catheter-based procedure
was recently introduced into clinical routine to treat drug-refractory paroxysmal atrial
fibrillation (PAF)1,2. During segmental ostial pulmonary vein isolation (PVI), electrically
conducting myocardial extensions bridging the pulmonary veins (PV) with the posterior wall of
the left atrium (LA) are disconnected to prevent the initiation (and the maintenance) of PAF.
Success rates reported in recent literature differ to a big extent (between 50 and 90%)3,4
and are not always comparable, as applied techniques may vary considerably and are changing
with growing experience in the same group. Moreover, evaluation of success is not consistent
within published reports, as clinical judgement of ablation outcome may be difficult to determine
(missing ECG documentation in symptomatic periods, asymptomatic episodes). In addition,
follow up periods are rarely comparable and sometimes are rather short, so that there is still a
lack of data addressing the long-term outcome in ablation of the PV ostia to treat PAF
nowadays.
We have reported on our early experience in the past5. In this paper we report on our own
short and long-term results with special consideration of distinct procedural parameters which
have been developed in a time period of three years from 2001 to 2004.
Patients and Methods
Lasso Procedure
Briefly, after puncture of one (or both) femoral and the left subclavian (in case the
coronary sinus can not be entered by a femoral access) vein(s) a multipolar electrode catheter is
introduced in the coronary sinus to record left atrial activity. Thereafter, a (usually double)
transseptal puncture is performed followed by pulmonary venography. Next, two electrode
catheters are placed in the LA via two long sheaths, one for ablation (Celsius THERMOCOOL
7F, Biosense Webster, Inc.) and one circular decapolar catheter (“Lasso”, Biosense Webster,
Inc.) to record electrical activity of myocardial extensions connecting the LA with a PV. The
lasso catheter is situated as proximal as possible inside the PV whereas the ablations catheter is
positioned at the very os to segmentally isolate the PV, thereby preventing stenosis which may
occur when delivering energy deep inside a PV. Electrical entrance block from the LA to the PV
is considered as the endpoint of the procedure which is documented by the elimination of PV
potentials on the Lasso catheter. We have been using irrigated ablation catheters from the very
beginning of our PV ablation experience, delivering up to 30 Watts of energy in the superior
PVs (left superior, LSPV and right superior, RSPV) and a maximum of 20-25 Watts in the
inferior PVs (left inferior, LIPV and right inferior, RIPV). The approach of targeting a PV for
ablation is “empiric” i.e. independent of its arrhythmic activity during the time of the procedure.
Indian Pacing and Electrophysiology Journal (ISSN 0972-6292), 6(1): 6-16 (2006)