Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3651_Библиотеки_им_академика_М_И_Перельмана
.pdf
120
https://t.me/medicina_free
F. Halbwachs et al.
Fig. 8.5 Upper panel: Telemetry tracing (ICD interrogation) showing the interval line (V), the far-eld ventricular electrogram (FF), and the local ventricular
electrogram (V) during VT.The VT cycle length is slightly
variable, between 367 ms and 382 ms. Lower panel:
Burst ventricular pacing (eight beats) efciently terminating the tachycardia. The pacing spikes are represented by
the blue vertical lines
ab
cd
8 Case 8
https://t.me/medicina_free
121
Fig. 8.6 Panel A. Cardiac MRI image in short-axis view
showing an enlarged left ventricle. Panel B. Short-axis
view showing an area of late gadolinium enhancement at
the level of the infero-septal wall of the LV (red arrow).
Electrophysiological Study andRF
Catheter Ablation Procedure
Panel C and D. Two-chamber view showing the presence
of late gadolinium enhancement in the infero-apical area
of the LV (C) and in the infero-basal area (D)
Boston Scientic®) was introduced in a 6F 20cm
vascular sheath and was subsequently advanced
via the right common femoral vein up to the right
The ablation procedure was performed under
local anesthesia and conscious sedation. Vascular
access was obtained using the modied Seldinger
technique, under Doppler ultrasound guidance. A
6F quadripolar non-steerable catheter (Viking,
ventricular apex. A decapolar steerable catheter
(Inquiry, Abbott®) was introduced in a 7F 20cm
vascular sheath inserted at the level of the right
common femoral vein and positioned in the coronary sinus, with the distal electrodes situated at
122
https://t.me/medicina_free
F. Halbwachs et al.
the level of the infero-lateral part of the mitral
annulus and the proximal poles just distal to the
coronary sinus ostium.
The CARTO® 3 electro-anatomic mapping
system (Biosense Webster, Johnson & Johnson)
was used to guide mapping and ablation.
Ventricular pacing was carried out at twice the
diastolic threshold using the EP-4™ Cardiac
Stimulator (Abbott®) system. Surface ECG and
intracavitary ECGs were recorded by the
WorkMate Claris™ System (Abbott®).
Baseline measurements are shown in Figs.8.7
and 8.8. The QRS width measured 170 ms and
the PR interval 152ms (Fig.8.7). The basal HV
interval measured 91ms (Fig.8.8).
Fig. 8.7 A 12-lead ECG at the beginning of the ablation procedure showing sinus rhythm with a heart rate of 82bpm,
QRS axis at −75°, LBBB, QRS duration of 170ms, and PR=152ms
Fig. 8.8 A 12-lead ECG together with intracavitary leads
VD 1–2 and VD 3–4 recorded from the distal and proximal electrodes of the right ventricular catheter positioned
at the right ventricular apex and the distal and proximal
electrodes from the coronary sinus catheter placed at the
level of the bundle of His, showing a prolonged HV interval of 91ms
8 Case 8
https://t.me/medicina_free
123
Programmed ventricular stimulation was performed before and after isoprenaline infusion
with induction of a wide QRS complex tachycardia with a cycle length of 360ms (Fig.8.9).
Question 1: What is the most likely form
of the tachycardia presented in Fig. 8.9?
A. Reentry in the left posterior fascicle.
B. Reentry in the left anterior fascicle.
C. Upper septal fascicular ventricular
tachycardia.
D. Bundle branch reentry ventricular
tachycardia.
E. AVNRT + right bundle branch block.
Given the personal medical history of the
patient and the aspect of the tachycardia induced
during PVS, a VT with origin in the left posterior
fascicle was suspected. Mapping of the left ventricle was therefore seen as the next best step and
was subsequently performed. Of note, the
absence of a His potential before each QRS complex (Fig. 8.10) was not in favor of a bundle
branch reentry tachycardia.
Access to the left ventricle was obtained using
a retrograde approach by puncturing the right
common femoral artery using the modied
Seldinger technique, under Doppler ultrasound
guidance. A Pentaray catheter (Biosense Webster,
Johnson & Johnson) was introduced in a 9F
20 cm vascular sheath and was subsequently
advanced via the aorta to the LV.It was used to
perform the anatomical and the bipolar voltage
map of the LV.A Biosense Webster® SmartTouch
SF open-irrigated 3.5mm tip with double curve
D/F was used to perform RF ablation.
An anatomical map of the LV was rst created, which showed a slightly dilated LV, with a
volume of 170mL.A bipolar voltage map was
subsequently created during sinus rhythm, which
showed the presence of a few narrow areas of
low-voltage electrograms at the level of the basal
and mid-septal wall of the LV (Fig.8.11).
Fig. 8.9 A 12-lead ECG at 25 mm/s showing the wide
QRS complex tachycardia induced during programmed
ventricular stimulation, after isoprenaline infusion (RV
apical pacing during spontaneous rhythm, with an S2
extrastimulus delivered at a coupling interval of 250ms)
124
https://t.me/medicina_free
F. Halbwachs et al.
Fig. 8.10 A 12-lead ECG together with intracavitary
tracings recorded from the distal and proximal electrodes
from the right ventricular apex catheter positioned at the
right ventricular apex and the distal and proximal elec-
Fig. 8.11 CARTO image in RAO 45° showing the bipolar voltage map of the LV recorded in sinus rhythm, with
a small and narrow area of low (<0.5mV, in red) and borderline (0.5–1.5mV, in green and blue) voltage at the level
of the IVS, possibly corresponding to the RF ablation
trodes from the coronary sinus catheter placed at the level
of the bundle of His. The tachycardia cycle length is
360ms
lesions deployed during the rst catheter ablation procedure. The orange dot represents the His bundle. The outer
transparent shell represents the exterior layer of the LV
myocardium, evidenced by the superposed 3D reconstruction of the cardiac CT angiography image
Identication of the His bundle, the left bundle, and Purkinje network was subsequently performed during sinus rhythm, by placing the
ablation catheter at the level of the septal wall of
the LV and carefully searching for sites where a
sharp local electrogram preceded the local bipolar ventricular electrogram (Fig.8.12).
Of note, mapping the LV with the Pentaray
catheter was extremely difcult, since the slightest contact between the catheter branches and the
LV myocardium induced long runs of polymorphic VT (Fig.8.13).
8 Case 8
https://t.me/medicina_free
125
Fig. 8.12 CARTO image in RAO 47° caudal 40° showing the bipolar voltage map of the LV recorded in sinus
rhythm (same as in Figs.8.9 and 8.10). The Pentaray catheter is positioned at the level of the posteroinferior fascicle and records a Purkinje potential (right upper part of the
Fig. 8.13 Runs of polymorphic VT mechanically induced by the contact between the branches of the Pentaray catheter
and the LV myocardium
image), represented by a sharp deection preceding the
surface QRS complex (P 13–14). The activation of the
His-Purkinje network is late in this area, with the Purkinje
potential being recorded after the beginning of the QRS
complex
Mapping of the LV was continued with the
ablation catheter, with emphasis on the left posterior fascicle (Fig.8.14).
After the His-Purkinje network was identied,
programmed ventricular stimulation was repeated
with the aim of inducing the clinical VT.However,
despite administration of isoprenaline and a rig-
orous stimulation protocol (three sites: RV apex,
RVOT, LV; up to three extrastimuli, burst atrial,
and ventricular pacing), the VT was not inducible. This might have been due to mechanical
supercial injury of the conduction system (left
posterior fascicle) during the thorough mapping
phase.
126
https://t.me/medicina_free
Fig. 8.14 CARTO
image in RAO 45°
caudal 35° showing the
bipolar voltage map of
the LV recorded in sinus
rhythm (same as in
Fig.8.9). The roving/
ablation catheter is
positioned at the level of
the posteroinferior
fascicle and records a
Purkinje potential (right
upper part of the image),
represented by a sharp
deection preceding the
surface QRS complex
(Map 1–2)
Question 2: What would your strategy
be at this point of the procedure?
A. Terminate the procedure. Ablation is no
longer necessary, since the VT is no longer inducible.
B. Terminate the procedure. No ablation
should be done if the mechanism of the
VT is uncertain.
C. Wait for 1h and hope that conduction at
the level of the posterior fascicle recovers and perform programmed ventricular stimulation once again.
D. Administer higher doses of isoprenaline
and perform programmed ventricular
stimulation once again.
E. Perform anatomical (substrate) ablation,
considering the VT reentry in the posterior fascicle, based on the result of the
rst EP study and on the 12-lead ECG
morphology of the VT.
VT non-inducibility is indeed the end point
of a VT ablation procedure; however, this
should be accomplished by RF ablation, and
VT inducibility before any RF ablation is performed is not a marker of long-term success. A
waiting period of 30min was granted, and programmed atrial and ventricular stimulations
F. Halbwachs et al.
were performed again, before and after isoprenaline infusion, but without VT induction. Given
the result of the rst EP study and based on the
12-lead ECG morphology of the VT, reentry in
the posterior fascicle was considered highly
likely, and an anatomical ablation of the VT
substrate was chosen as the next step of the procedure. This option was chosen taking into
account the fact that the patient presented a
complete left bundle branch block during sinus
rhythm, and performance of an anatomical
ablation transecting the left posterior fascicle
was an acceptable option in the presence of a
LBBB in this patient.
RF ablation was performed with a target
power of 30W and a target ablation index of 450.
A line of ablation at the level of the septal LV
wall, transecting the left posterior fascicle, was
created, guided by locally recorded Purkinje
potentials (Fig.8.15).
The mechanism of a reentry in the left posterior fascicle is depicted in Fig.8.16.
After the ablation, programmed atrial and
ventricular stimulations were again performed,
without inducting any VT (Fig.8.17). However,
given the lack of VT induction after the mapping
phase, this was not considered as a hard acute
success marker.
There were no complications related to the
procedure.
8 Case 8
https://t.me/medicina_free
Fig. 8.15 CARTO
image in RAO 45°
showing the anatomical
map of the LV with RF
ablation lesions (pink
and brown dots)
superposed at the level
of the distal posterior
fascicle
127
Fig. 8.16 CARTO image in RAO 45°caudal 55°showing
the anatomical map of the LV with RF ablation lesions
(pink and brown dots) superposed at the level of the distal
posterior fascicle, depicting the theoretical VT circuit.
The antegrade limb is represented by slowly conducting
The ECG post-ablation is shown in Fig.8.18.
Forty-eight hour telemetry surveillance did
not record any arrhythmias post-RF ablation.
The patient was discharged from the hospital
48 h after the ablation procedure on no antiarrhythmic drug.
A telemetric control of his ICD 24days after
the RF ablation procedure showed no VT recurrence (Fig.8.19).
verapamil bers (curved red arrow, 1), and the retrograde
limb of the circuit is represented by the posterior fascicle
of the left bundle (vertical red line, 2). The bottom of the
blue line represents the lower turnaround point, with its
peak pointing at the theoretical exit site (3)
Answers
Question 1: A.Reentry in the left poste-
rior fascicle.
Question 2: E.Perform anatomical (sub-
strate) ablation, considering the VT
reentry in the posterior fascicle, based
on the result of the rst EP study and
on the 12-lead ECG morphology of
the VT.
128
https://t.me/medicina_free
F. Halbwachs et al.
Fig. 8.17 A 12-lead ECG together with intracavitary
leads recorded from the distal and the proximal electrodes
of the roving/ablation catheter (Abl d, Abl p), from the
distal and the proximal electrodes of the quadripolar cath-
Fig. 8.18 A 12-lead ECG after the ablation procedure showing sinus rhythm with a heart rate of 66bpm, QRS axis at
−75°, and complete LBBB
eter placed at the level of the RV apex (VD 1,2 and VD
3,4) showing the absence of induction of VT post-RF
ablation during the control programmed ventricular
stimulation
8 Case 8
https://t.me/medicina_free
129
Fig. 8.19 Telecardiology tracing recorded 24days after the RF ablation procedure showing the absence of any ventricular arrhythmia
Commentary
rior fascicular VT is characterized by RBBB and
left axis deviation and a QRS duration between
The above-presented case illustrates a catheter
ablation procedure of fascicular ventricular
tachycardia in a patient with LBBB and a prior
failed catheter ablation procedure. Several observations about this case merit further discussion.
Fascicular ventricular tachycardia is a particular form of VT that can be encountered in both
patients with and without structural heart disease.
Three forms of fascicular VT have been described:
(1) reentry in the posterior fascicle (left posterior
fascicular VT), which is responsible for approximately 90% of cases [1, 2]; (2) reentry in the
anterior fascicle (left anterior fascicular VT),
responsible for about 8–9% of cases; and (3)
upper septal fascicular VT, which is the rarest
form, responsible for 1–2% of cases.
Fascicular VT can be recognized on the
12-lead ECG by certain features: (1) Left poste-
120 ms and 140 ms, (2) left anterior fascicular
VT has a RBBB and right axis deviation and a
QRS duration between 120ms and 140 ms, and
(3) upper septal fascicular VT has a RBBB, normal axis, and a narrow QRS complex (< 120ms).
Exceptionally, it can have LBBB morphology,
normal axis with a QRS transition in precordial
leads in V3 or V4 [3].
The differential diagnosis based on the 12-lead
ECG is made with VT originating from the
papillary muscles and VT originating in the myocardium around the mitral annulus [4–6] as well as
SVT with aberrancy. In practice, differentiation of
fascicular VT from papillary muscle VT can be
difcult, since Purkinje bers may exist at the base
of the papillary muscles and myocardial bers
from the papillary muscles can be found extending
at the level of the interventricular septum [3].
Соседние файлы в папке Библиотека им академика М.И. Перельмана