3/3/2010
BY
Dr. Rania samir
Lecturer off Cardiology
d l
Ain Shams University
Atrial flutter represents the most important &
most common atrial tachyarrhythmia after AF
The re-entry circuits often occupy large areas
of the atrium & are referred to as “macro
macro-
reentrant”
The overall incidence of atrial flutter in a
recent population study was 0.88%,
0.05% in patients < 50 years old
5.87% among individuals > 80 years of age.
(Granada et al, 2000)
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3/3/2010
Many different forms of atrial flutter exist & since it
was first described in 1911,
1911 many terms have been
used to characterize atrial flutter, particularly
recently, to the point that atrial flutter terminology
has become quite confusing
This has led to multiple classification schemes.
schemes
First simple classification based on ECG patterns, in
1970
yp
-Typical atrial flutter ((Counter-clockwise))
- Atypical atrial flutter (Clockwise)
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3/3/2010
Based on advanced EP mapping techniques which identified different EP-
mechanisms of atrial flutter
Isthmus dependent Non-Isthmus dependent
Atypical atrial flutter
atrial flutter atrial flutter
The re-entry circuit is any fixed Type II atrial flutter
confined to RA & involves macroreentrant atrial
heterogenous flutter
the CTI as a critical zone of circuit that doesn’t
wave morphology
slow conduction involve the CTI
May be due to rapid
y with
reentry
• CCW A. flutter
variable fib.
(commonest 90%) • Lesion macroreentrant Conduction
atrial tachycardia (most
• CW A. flutter (less
common)
commom 10%)
• upper loop reentry
• Lower loop re-entrry
• LA flutter (rare)
ACC/AHA/ESC Guidelines 2003
isthmus dependent atrial
flutter was determined to be
due to a macroreentrant
circuit rotating in either a CT
counterclockwise
(common) or clockwise IAS
(uncommon) direction in
th right
the i ht atrium,
ti with
ith an CS
area of relatively slow ER
IVC
conduction in the low TA
posterior right atrium
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Atrial flutter is most often a nuisance arrhythmia & its
clinical significance lies largely in its frequent
association with AF or rapid ventricular response
which is principally responsible for many of the
associated symptoms So, maintenance of SR after
CV is mandatory in cases of recurrent A.flutter
Based on the available long term data
data, drug treatment
offered a limited ability to maintain SR without
occasional to frequent recurrences of A.flutter, even
when multiple agents are used.
Reported long term success rates ranging from 50% for
class I to 73% for class III (oral dofetilide)
Also, long-term rate control alone usually requires large
doses of AV nodal blocking agents
Singh et al, Circulation 2000
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Approaches to endocardial mapping of A flutter
include standard multielectrode catheters, Expanding
electrode
l t d arrays or 3D mapping i ttechniques
h i b
butt still
till
Standard multielectrode catheter-based mapping still
remains the main tool for the study of A flutter
The recent advances in this therapeutic
approach h were associated
i t d with
ith high
hi h success
rates, low recurrence rates and minimal
complications.
LAO LAO
IAS
IAS
Isthm
IVC
Isthm
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Large randomized trials, RF- ablation creating linear lesions
across the critical zone of slow conduction (CTI) till achievement
off CBIB as an endpoint
d i t off ablation
bl ti
High success rates 90-100%
Low recurrence rate 6-9%
over a period of 9-17 mo
(Tai et al., 1998) (Wu et al.,2002)
LAO RAO
Ain Shams University EP lab
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Complete CW block
During PCS pacing
Before ablation After ablation
Ain Shams University EP lab
LRA pacing Complete CCW block
Before ablation After ablation
Ain Shams University EP lab
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Variation in the isthmus width
Isthmus width 17-54 mm
g <81°
Isthmus width > 39 mm or Cath-IVC angle assoc with difficuilty
y of
reaching TA
Wide isthmus (49 mm) Craniocaudally elongated
making sharp angle RA with short isthmus (17
with IVC 79° mm) Heidbüchel et al Circulation 2000
Variations in morphological features:
Prominent thick EV (20%)
of pts causing difficulty in
reaching behind EV
In ≈50% of pts the isthmus has global
needing abl cath with
concave morphology (A)
shorter curve
In ≈ 45% of pts the isthmus is divided
pouch like recess (varying from 1.5 to into flat smooth vestibule near TA
9.4 mm deep), > 5mm deep pouch side & pouch like recess near IVC
Heidbüchel et al Circulation 2000 side (4.3±2.1 mm)
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3/3/2010
Comparing the published success rates of AADs in
maintaining SR to significantly high long term success rates
of RF-ablation Favors RF ablation as an acceptable
therapeutic approach of A . flutter
ACC/AHA/ESC guidelines,2003
Although the success rates of RF-ablation
using conventional & 3D mapping techniques
are similar
Shorter fluoroscopy time (3.9±15 vs 22 ±6.3 min)
(Kottkamp et al, 2000)
Precise identification of discrete gaps within
non-contiguous lesion lines the ability to
renavigate to previously mapped & ablated
sites
Fast & reliable identification of WSDP along
the ablation line
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TCL 240 ms
Ain Shams University EP lab
CS pacing after ablation CS pacing before ablation
showing CW isthmus block
Ain Shams University EP lab
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Before ablation
After ablation
Ain Shams University EP lab
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3/3/2010
Isthmus ablation in patients with atrial flutter has
proved positive impact on QOL.
Catheter ablation is curative in many patients
obviating the need for life-long AADs, and may be
more cost effective on the long term than AAD
therapy.
Substantial fluoroscopy exposure, which is necessary
f conventional
for ti l isthmus
i th ablation,
bl ti iis significantly
i ifi tl
reduced with 3D mapping for isthmus ablation which
have an impact on the long-term safety of this invasive
treatment strategy.
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