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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3651_Библиотеки_им_академика_М_И_Перельмана
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Fig. 4.4 Chest X-ray in posteroanterior view showing a
non-enlarged cardiac silhouette, with a normal cardiothoracic index, absence of pleural effusion, and no pulmonary stasis
Fig. 4.5 CT angiography image showing non-dilated left
and right ventricles, mild LV hypertrophy, and absence of
LV thrombus
Electrophysiological Study andRF
Catheter Ablation Procedure
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intracavitary ECGs were recorded by the
WorkMate Claris™ System (Abbott®).
Vascular access was obtained using the modied Seldinger technique, under Doppler ultrasound guidance. A 3.5 mm Navistar ST SF
catheter with open-irrigated tip and double curve
D/F (Biosense Webster, Johnson & Johnson®)
was introduced in a 8F 20cm vascular sheath and
was subsequently advanced to the right common
femoral vein and gently advanced at the level of
the right common iliac vein, under constant
impedance surveillance on the RF generator. The
presence of the roving/ablation catheter at the
level of the femoral, iliac vein, and IVC generated an impedance between 140 and 170ohms.
The entrance of the catheter in a collateral vein
was rapidly accompanied by a rise in the local
impedance of up to 350 ohms, and this determined retraction of the catheter in a previous
position. The catheter was then gently oriented in
a different manner, in such a way that its advancement determined a relatively constant impedance. The CARTO ® 3 electro-anatomic mapping
system was used to create an anatomical map of
the right common iliac vein and of the IVC, up to
the point where the catheter entered the right
atrium, and atrial electrograms were recorded by
the distal electrode of the roving/ablation
catheter.
Next, an anatomical map of the right atrium
was created during sinus rhythm, with emphasis
on the superior vena cava, the coronary sinus, and
the tricuspid valve, with the identication of the
bundle of His and the coronary sinus ostium. The
roving/ablation catheter was then placed inside
the right ventricle.
The ECG at the beginning of the ablation procedure is presented in Fig.4.6.
The ablation procedure was performed under
local anesthesia and conscious sedation, without
the use of a uoroscopy, with the help of the
CARTO® 3 electro-anatomic mapping system
(Biosense Webster, Johnson & Johnson).
Ventricular pacing was carried out at twice the
diastolic threshold using the EP-4™ Cardiac
Stimulator (Abbott®) system. Surface ECG and
Question 2: Where is the most likely origin of the PVC 1 presented in Fig. 4.1?
A. RVOT
B. LVOT
C. LV summit
D. Right sinus of Valsalva
E. Left sinus of Valsalva
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Fig. 4.6 A 12-lead ECG recorded at the beginning of the ablation procedure showing sinus rhythm with a heart rate
around 70bpm, QRS axis at +60°, and the presence of isolated PVCs of two morphologies
F. Halbwachs et al.
Fig. 4.7 A 12-lead ECG leads together with intracavitary
leads recorded by the distal and the proximal bipolar electrodes of the ablation catheter (ABL d and ABL p) show-
Question 3: Where is the most likely ori-
gin of the PVC 2 presented in Fig. 4.1?
A. Inferior wall of the RV
B. LVOT
C. Aorto-mitral continuity
D. Para-Hisian
E. Postero-septal wall of the LV
ing the AH and HV interval at the beginning of the
electrophysiological study, of 109 and 43 ms,
respectively
The AH and the HV interval were of 109 and
43ms (Fig.4.7).
A careful analysis of the ECG in Fig.4.6 identied two PVC morphologies, likely corresponding to the PVCs recorded by the ECG in Fig.4.1.
Of note, due to the fact that debrillator external
patches and the patches used by the CARTO system were also placed on the patient’s chest before
the beginning of the ablation procedure, the ECG
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Fig. 4.8 Left panel: CARTO image of the right ventricle
in PA view showing the superposed cardiac CT angiography 3D reconstruction image (glass-like, transparent silhouette) and the anatomical map of the RV acquired with
the roving/ablation catheter, shown inside the RV. The
activation map of the RVOT during PVCs is superposed
on the anatomical map, showing an area of early endocardial activation (red color at the top of the roving/ablation
catheter), preceding the onset of the QRS onset on the surface ECG by 16ms. The area is situated in the upper posterior part of the RVOT, just below the pulmonic valve.
electrodes of leads V1, V2, right shoulder, and
left shoulder were not placed as those that were
used to record the ECG in Fig. 4.1. This could
explain the slightly different morphology of the
two PVCs from the two ECGs, even though they
likely correspond to the same two PVCs. Another
argument for this would be the presence of only
two morphologies on the 24-h Holter ECG.
Given the fact that PVC 1 from Fig.4.6 shows
LBBB inferior axis, with QRS transition in the
frontal plane in lead V3–V4, a possible origin in
the RVOT was considered. Therefore, mapping
of this PVC was commenced in the right ventricle. PVC 2 has a right bundle branch block morphology superior axis, with a tall R wave from
V1 to V6, suggesting an origin in the inferior and
basal area of the left ventricle.
Using the roving/ablation catheter, an anatomical map of the RVOT was initially created, which
showed the presence of a non-dilated RVOT.Next,
Right panel: The same view as in the left panel, but
showing the bipolar voltage map of the RV superposed on
the anatomical map of the RV. Red areas correspond to
values <0.5 mV and are considered scar tissue; yellow,
green, and blue represent borderline values of 0.5–1.5mV;
and violet represent values of >1.5mV, corresponding to
healthy myocardial tissue. The local signal recorded by
distal bipolar electrode of the roving/ablation catheter
during PVC 1 is presented in the upper left corner of the
image, together with surface ECG lead II
an activation map of the RVOT during the frequent PVCs 1 was created. This showed the presence of an early activation site at the level of the
posterior and superior wall of the RVOT, just
below the pulmonary valve, from where the activation of the RVOT spread in a radial manner,
suggesting a focal activation pattern (Fig.4.8). At
this site, the unipolar electrogram recorded by the
roving/ablation catheter had a “rS” aspect. The
local bipolar ventricular electrogram preceded
the surface ECG QRS complex by 16 ms
(Fig.4.9).
Question 4: Is this a good ablation site?
A. Yes, the earliest bipolar local electro-
gram precedes the surface QRS by
16ms and this should be enough for a
successful RF application.
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F. Halbwachs et al.
Fig. 4.9 A 12-lead ECG together with intracavitary leads
recorded by the distal and the proximal bipolar electrodes
of the ablation catheter (MAP 1–2 and MAP 3–4) placed
at the earliest endocardial activation site in the RVOT
B. Yes. The activation map of the RVOT
indicates a focal mechanism originating
from this site.
C. No. The earliest endocardial activation
in the RVOT precedes the beginning of
the QRS complex by only 16 ms, and
showing the local ventricular electrogram preceding the
onset of the QRS complex by 16ms. MAP 1 represents
the unipolar electrogram recorded by the distal electrode
of the roving/ablation catheter
this is usually not good enough for a
successful lesion.
D. No. The local unipolar electrogram
recorded by the distal electrode of the roving/mapping catheter has an “rS” pattern.
E. I don’t know.
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Given the presence of a “small r wave” shown
by the local unipolar electrogram of the roving/
ablation catheter at the earliest activation site in
the RVOT, this was considered to indicate a suboptimal ablation site.
Question 5: What would be the next best
step at this point of the procedure?
A. Map the coronary sinus to look for an
epicardial origin of the PVCs.
B. Map the LV.
C. Map the aortic sinus of Valsalva region.
D. Terminate the procedure and suggest
antiarrhythmic medication.
E. I don’t know.
Given the likelihood of an extra RVOT origin
of the PVC, mapping of the coronary sinus was
thought as the next best step, in order to try to
map the triangle of Brocq and Mouchet, looking
for a potential epicardial origin of this PVC, in
the LV summit region. The roving/ablation catheter was advanced inside the great cardiac vein,
but it could not be advanced in its distal part,
probably due to the small diameter of the vein.
The earliest activation in the great cardiac vein
during PVC 1 did not precede the onset of the
QRS complex on the 12-lead ECG (Fig.4.10).
Next, mapping of the aortic sinus of Valsalva
was decided, given the anatomical relationship
between the aorta and the posterior part of the
RVOT.
Access to the aortic root was obtained using
the retrograde approach. The right common fem-
Fig. 4.10 CARTO image in left lateral view of showing
the superposed cardiac CT angiography 3D reconstruction image (glass-like, transparent silhouette), the activation map of the RV, and the activation map of the coronary
sinus, with the roving/ablation catheter inside it. The earliest activation site inside the coronary sinus does not precede the earliest activation site inside the RVOT.Further
advancement of the roving/ablation catheter in the distal
part of the great cardiac vein was not possible. Right
panel: The same view as in the left panel, but showing the
bipolar voltage map of the RV superposed on the anatomi-
cal map of the RV. Red areas correspond to values
<0.5 mV and are considered scar tissue; yellow, green,
and blue represent borderline values of 0.5–1.5mV; and
violet represent values of >1.5 mV, corresponding to
healthy myocardial tissue. The local signal recorded by
distal bipolar electrode of the roving/ablation catheter
during PVC 1 is presented in the upper part of the image,
together with surface ECG lead II, showing the local ventricular electrogram recorded by the roving/ablation catheter from the coronary sinus as not preceding the QRS
complex
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F. Halbwachs et al.
oral artery was punctured using the Seldinger
technique under echocardiographic guidance,
and a 9F 20cm sheath was inserted.
Anticoagulation was obtained with unfractionated heparin 100 UI/kg as IV bolus, with a
target ACT between 300 and 350s.
Once anticoagulation was achieved, the roving/ablation catheter was introduced in the common femoral artery and retrogradely advanced to
the level of the aortic sinus of Valsalva.
Subsequently, an anatomical map of the coronary cusp region and of the base of the aorta was
performed. Next, an activation map of the aortic
cusps was created during PVC 1, with identication of an early activation site at the level of the
left main coronary artery, which preceded the
onset of the QRS complex by 21–22ms, where
the unipolar electrogram had a “QS” aspect
(Figs.4.11 and 4.12).
Figure 4.13 shows the anatomical relationship between the earliest activation site during
PVC 1in the left sinus of Valsalva region and the
origin of the left main coronary artery (CT angiography reconstruction, performed before the
ablation procedure). The origin of PVC 1 seems
to be at the origin of the left main coronary
artery.
The anatomical relationship between the posterior wall of the RVOT and the left sinus of
Valsalva with the origin of the left main coronary
artery is presented below. The anatomical maps
of RVOT and the aortic root performed with the
roving/ablation catheter, with superposed activation maps, is shown (Figs.4.14 and 4.15).
Question 6: Would you perform ablation
at this site?
A. Yes. The earliest bipolar local electro-
gram precedes the surface QRS by
21–22ms, and this should be enough for
a successful RF lesion. Ablation should
be performed here.
Fig. 4.11 CARTO image in LAO 50° of showing the
superposed cardiac CT angiography 3D reconstruction
image of the aorta (glass-like, transparent silhouette) and
the activation map of the ascending aorta during PVC 1.
The earliest activation site (the area where the roving/
ablation catheter is situated) is recorded just inside the ori-
gin of the left main coronary artery and precedes the onset
of the QRS complex by 21–22ms. The local bipolar electrogram recorded by the distal electrode of the ablation
catheter (MAP 1–2) is shown in the lower part of the
image, in blue, together with surface ECG lead II, in white
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B. Yes. The activation map of the aortic
sinus of Valsalva indicates a focal mechanism originating from this site.
Ablation should be performed here.
C. No. The earliest endocardial activation
in the left aortic sinus of Valsalva precedes the beginning of the QRS complex by only 21–22 ms, and this is
usually not good enough for a successful lesion.
D. No. Despite the good ablation criteria,
ablation at this site risks to induce acute
myocardial infarction.
E. Yes. Despite the risks associated with
ablation at this site, low- power RF energy
should be applied here (10–15W).
Fig. 4.12 A 12-lead ECG together with intracavitary
leads recorded by the distal and the proximal bipolar electrodes of the ablation catheter (MAP 1–2 and MAP 3–4)
placed at the earliest endocardial activation site in the left
sinus of Valsalva, at the origin of the left main coronary
artery, showing the local ventricular electrogram preceding the onset of the QRS complex by 21–22ms. MAP 1
represents the unipolar electrogram recorded by the distal
electrode of the roving/ablation catheter and has a “QS”
aspect
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Fig. 4.13 CARTO
image in LAO 30°
caudal 40° of showing
the superposed cardiac
CT angiography 3D
reconstruction image of
the coronary arteries
(red color) and the
activation map of the
ascending aorta during
PVC 1. The earliest
activation site (the area
where the roving/
ablation catheter is
situated) is recorded just
inside the origin of the
left main coronary artery
and precedes the onset
of the QRS complex by
21–22ms
F. Halbwachs et al.
Fig. 4.14 CARTO image in LAO 120°, caudal 24° showing the activation map of the right ventricle and the aortic
sinus of Valsalva during PVC 1, emphasizing the anatomical relationship between the posterior wall of the RVOT
and the left sinus of Valsalva with the origin of the left
main coronary artery. Of note, the earliest activation site
at the level of the left sinus of Valsalva precedes the earliest ventricular activation site in the posterior RVOT by
only 5–6 ms. The local bipolar ventricular electrogram
recorded in the RVOT is shown in the left upper corner in
blue, preceding the onset of the QRS complex on the surface ECG lead II (in white)
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Fig. 4.15 CARTO image in posterior, caudal 10° showing the activation map of the right ventricle and the aortic
sinus of Valsalva during PVC 1, emphasizing the anatomical relationship between the posterior wall of the RVOT
and the left sinus of Valsalva with the origin of the left
coronary artery. The roving/ablation catheter is seen
entering the left main coronary artery. Of note, the earliest
Optimal ablation criteria were found in the left
sinus of Valsalva, close to the ostium of the left
main coronary artery. However, ablation at this
site is associated with a very high risk of myocardial infarction, provoked by thrombotic occlusion of the left main coronary artery. Therefore,
ablation in this area was not performed.
Question 7: What would be the next best
step at this time of the procedure?
A. Remap the RVOT and look for a better
ablation site.
B. Perform remapping of the coronary
sinus with a thinner ablation catheter, in
order to reach the distal part of the great
cardiac vein.
C. Terminate the procedure and suggest
antiarrhythmic medication.
activation site at the level of the left sinus of Valsalva precedes the earliest ventricular activation site in the posterior RVOT by only 5–6ms. The local bipolar ventricular
electrogram recorded at the origin of the left main coronary artery is shown in the left upper corner in blue, preceding the onset of the QRS complex on the surface ECG
lead II (in white)
D. Map the LVOT region.
E. I don’t know.
Mapping of the LVOT was considered as the
next best step in this procedure, given the anatomical relationship between the basal anterior LV wall
and the origin of the left main coronary artery.
An anatomical map of the LVOT was therefore subsequently created. An activation map of
the LVOT was created thereafter during PVC 1. A
small zone of early local ventricular activation
was found at the level of the anterior and basal
LVOT, where the local bipolar electrogram preceded the surface QRS by 14ms (Fig.4.16). Of
note, the earliest activation site in the left sinus of
Valsalva preceded the onset of the QRS complex
by 21–22ms. However, the unipolar electrogram
recorded by the roving/ablation catheter in this
area of the LVOT had a “QS” aspect (Fig.4.17).
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F. Halbwachs et al.
Fig. 4.16 CARTO image in LAO 35° cranial 75° showing the activation map of the left ventricular outow tract
during PVC 1. The roving/ablation catheter is positioned
at the level of the earliest activation site in the anterior
LVOT, which is recorded 7–8 ms later than the earliest
activation site in the left sinus of Valsalva. In red, the 3D
reconstruction of the CT angiography images of the coro-
nary arteries is shown. Note the very close proximity of
the left main coronary artery to the earliest activation site
in the LVOT.The local ventricular electrogram recorded
by the roving/ablation catheter is shown in blue in the bottom part of the image, together with its relationship to the
QRS complex onset on the surface ECG in lead II (in
white)
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