Monday, 1 September 2008 - European Heart Journal

288 Atrial fibrillation
modelling characterised by interstitial fibrosis, atrial enlargement, slowed and
heterogenous conduction, increased effective refractory periods and a greater
propensity for AF. These findings highlight the importance of early and aggressive
therapy for hypertension to prevent the development of arrhythmogenic substrates.
P1902 Incidence of atrial fibrillation after percutaneous
closure of patent foramen ovale and small atrial
septal defects in patients presenting with cryptogenic
stroke: a case-control study
R. Bonvini, R. Sztajzel, M. Righini, P.A. Dorsaz, J. Alibegovic,
C. Bonvin, U. Sigwart, E. Camenzind, V. Verin, J. Sztajzel on behalf of NA.
University Hospital of Geneva, Cardiology, Geneva, Switzerland
Background and Purpose: The occurrence of atrial fibrillation (AF) after percutaneous
closure of a patent foramen ovale (PFO) for cryptogenic stroke has been
reported in a variable percentage of patients. However, its precise incidence and
mechanism are presently unclear and remain to be elucidated.
Methods and Results: We started from 2002 onwards an arrhythmia follow-up
(FU) protocol performing a 7-day event-loop-recording (ELR) at day 1, after 6 and
12 months in patients who underwent a percutaneous PFO closure procedure for
cryptogenic stroke. Ninety-two patients (Closure Group) were so far followed and
then compared to a similar Control Group of 51 patients who did not undergo the
PFO closure for several reasons. The incidence of AF was similar in both study
groups during a FU of 12 months, including 7.6% (95% CI: 3.1%-15.0%) in the
Closure Group and 7.8% (95% CI: 2.18%-18.9%) in the Control Group (p=1.0).
The presence of a large PFO was the only significant risk factor for the occurrence
of AF irrespective of the type of the administered treatment (i.e. interventional or
medical). The odds ratio was 6.596 (95% CI, 1.660–26.21; P=0.0051).
Conclusions: Patients with cryptogenic stroke and PFO had a rather high incidence
of AF during a FU of 12 months, irrespective if the PFO was percutaneously
closed or medically managed. The presence of a large PFO was the only
significant predictor of AF occurrence during FU. Meticulous AF detection protocols
should be performed in all cryptogenic stroke patients, especially in those
scheduled for PFO-closure.
P1903 Combined anatomical and electrogram-guided
approach in catheter ablation of atrial fibrillation
G.B. Nam, K.M. Park, K.J. Choi, Y.H. Kim. Asan Medical Center,
Univ Ulsan Coll Med, Cardiology, Seoul, Korea, Republic of
Purpose: Current catheter ablation of atrial fibrillation (AF) is focused
on the elimination of pulmonary vein (PV) potentials. Tailored approach based on
complex fractionated electrograms (CFE) has been proposed. Additive effect of
this electrogram-guided approach in addition to the anatomical PV antral isolation
has not been reported.
Methods: 1. Patients with symptomatic, drug-refractory AF (paroxysmal, 76, persistent,
29 pts) were included. 2. Catheter ablation was guided by fluoroscopy
or 3D mapping system (NavX or CARTO). 3. PV antral isolation (PVAI) was
performed targeting elimination or dissociation of PV potentials. After PVAI,
electrogram-guided ablation was continued targeting CFEs or high-frequency activity
relative to the surrounding areas. 4. End-point of the procedure was noninducibility
of AF in pts with paroxysmal AF (PAF), termination into sinus rhythm
in pts with persistent AF (PeAF).
Results: 1. In PAF, PVAI alone rendered AF non-inducible in 42 of 79 pts (55%).
After electrogram-guided ablation, AF became non-inducible in additional 12 pts
(16%), while only atrial flutters (AFL) were induced in 16 pts (21%). AF persisted
in 6 pts (8%) after this combined ablation procedure. In 16 pts with inducible
AFL (27 AFLs), mechanisms of tachycardia included right isthmus dependent in
5/27, perimitral in 4/27, roof-dependent in 4/27, focal in 8/27, and unknown in
6/27 AFLs. 2. In PeAF, PVAI restored sinus rhythm in 0/29 pts. After electrogramguided
ablation, AF converted directly into sinus rhythm in 2(7%) and into AFLs
in 19 pts (65%), while AF persisted in 8 pts (28%). In 19 pts with AFLs (38 AFLs)
converted from AF, mechanisms of tachycardia were right isthmus dependent in
12/38, perimitral in 11/38, roof-dependent in 5/38, focal in 6/38, and unknown in
4/38 AFLs.
Conclusions: Electrogram-guided ablation targeting CFEs after PVAI resulted in
non-inducibility of AF in pts with PAF, or conversion of AF into AFL in pts with
PeAF. The major mechanism of the induced or converted AFLs during this combined
procedure was macroreentry around the large anatomic obstacles such as
tricuspid/mitral annulus or PVs.
P1905 Anatomical differences in the coronary venous
system in patients with persistent atrial fibrillation
compared to patients in sinus rhythm
E. Arbelo Lainez, E. Caballero Dorta, J. Novoa Medina, A. Garcia
Quintana, A. Delgado Espinosa, C. Amador Gil, M.C. Rios Diaz,
A. Medina Fernandez-Aceytuno. Hospital de Gran Canaria Dr. Negrin, Servicio
de Cardiologia, Las Palmas De Gran Canaria, Spain
Introduction and Objective: The coronary sinus (CS) muscle sleeves have been
suggested to have role in the genesis of atrial fibrillation (AF), having been described
a higher probability of conversion to sinus rhythm (SR) by ablating at that
level in patients (p) with persistent AF. The aim was to describe the anatomy of
the coronary venous system in p with persistent AF.
Methods: The anatomy of the CS and its tributaries was studied by hyperemic
coronary venous return angiography and/or occlusive retrograde senovenography
in 319 p, 47 (15%) of which were in persistent AF (70% male, 64,8±10,5 years
left atrial diameter 47,5±6,6 mm).
Results: The diameter of the CS ostium was 17,3±5 mm with the presence of a
Thebesian valve in 37 p (79%) that covered 45,9±33,8% of the orifice and left an
opening into the right atrium of 12,1±6,3mm. The length of the CS was 42,3±12,8
mm and its diameter 13,3±2,7 mm, whereas that of the great cardiac vein (GCV)
was 10,7±2,7 mm. The oblique vein of Marshall was observed in 27 p (57%) and
the Vieussens valve (ViV) in 33 (70%), being the two associated in 25 p (53%). In
4 p an aneurismatic dilatation of the proximal CS (8,5%) was seen and in 32 (68%)
diastolic compression of the CS was present, 12 of which (25,5%) consisted of
a discrete muscular sleeve of 3 to 7 mm width. 4 p (8,5%) additionally showed
muscular sleeves over the tributary veins of the CS. The mean diameter of the
lateral vein was 4,2±1,4 mm. When comparing this group in persistent AF to the
272 p in SR, statistically significant differences were found in terms of diameter
of the CS ostium, the CS and GCV. The VoM were also more prevalent, with a
greater length and diameter. Finally, the ViV and an aneurismatic dilatation of the
proximal CS were also more frequent.
Conclusions: The anatomy of the CS and its tributaries has differential characteristics
in patients with persistent AF. This might play a role in the mechanisms
of AF or have implications in the design of the ablation procedure.
P1906 Time-dependent regional differences in sources of
oxidative stress in atrial fibrillation-induced
remodelling
S.N. Reilly1 , U. Schotten2 ,N.J.Alp1 , B. Casadei1 . 1University of Oxford, Cardiovascular Medicine, Oxford, United Kingdom;
2University of Maastricht, Physiology, Maastricht, Netherlands
Purpose: Atrial fibrillation (AF) is associated with electrical and structural atrial
remodelling and with increased myocardial oxidative stress, leading to reduced
nitric oxide (NO) bioavailability and NOS uncoupling. To date, it is unclear whether
oxidative stress is a trigger or a by-product of atrial remodeling. We evaluated the
time course and sources of superoxide (O2-) production in the right (RA) and left
(LA) atria of a goat model of pacing-induced AF.
Methods: Atrial O2- was assessed (lucigenin-enhanced chemiluminescence and
2-OH ethidium detection by HPLC) 14 days after the onset of AF (i.e. only electrical
remodeling presents) and after 6 months (electrical and structural remodeling).
The NOS cofactor BH4 and NOS activity were assessed by HPLC.
Results: In early AF O2- release was significanty increased in the LA only (Figure,
n=4). Inhibition of NADPH oxidases normalized O2- production in LA-AF but
had no effect in the RA or in SR. Atrial NOS activity and nNOS protein expression
but not BH4 level were reduced in both atria in AF.
In late AF, O2- release was greater in both atria (Figure). NADPH oxidase inhibition
did not affect O2- production, whereas inhibition of NOS or mitochondrial
Abstract P1905 – Characteristics of the CS in AF and SR
N Diameter Effective orifice Aneurismatic Diameter Diameter Presence of Diameter Presence of
of the CS ostium (mm) of the CS (mm) proximal CS (%) of the CS (mm) of the GCV (mm) VoM (%) of VoM (mm) ViV (%)
AF 47 17,3±5 12,1±6,3 8,5% 13,3±2,7 10,7±2,7 61% 2,04±0,7 75%
SR 272 13,4±4,4 8,9±4,1 2% 10,6±2,8 9,1±2,2 36% 1,6±0,8 57%
p