[ARVD-FORUM] Heart transplantation Dr. Zhang

[ARVD Symposium]

English - Spanish

Thank you very much Dr. Perez Riera. As emphasized by Dr. Martini
previously, the evidence-based population study is very important to learn
what is going on in Brugada syndrome (BrS) in terms of its pathophysiology.
It really doesn't matter as which hypothesis is right or wrong because it is
part of learning process for almost everything. The fact is that SCN5A
mutation-caused diseases are often associated with conduction abnormalities.
Recent study by Royer, et al (Circulation 2005;111:1738-46) showed the
evidence of correlations between SCN5A mutations and expression of connexins
in the transgenic mice model. Thus it is reasonable to consider, at least in
part, that the prolonged H-V interval and RBBB like patterns seen in BrS are
results from the conduction delay due to the structural remodeling overtime
(probably secondary to the SCN5A mutation) in the right ventricle. Such
structural abnormalities may be part of the explanations for the fatal VT/VF
and the basis for the ablation therapy.
Regards,

Li Zhang

-----------------------------

Muchas gracias Dr. Perez Riera. Como el Dr. Martini enfatizo antes, el
estudio de la poblacion basado en la evidencia es muy importante para saber
lo que ocurre en el Sindrome de Brugada (SBr) en terminos de su
fisiopatologia. Realmente no importa que hipotesis es correcta y cual no,
porque es parte del proceso del conocimiento para casi todo. El hecho es las
enfermedades causadas por la mutacion SCN5A con frecuencia estan asociadas
con anormalidades de la conduccion. Un estudio reciente de Royer y cols.,
(Circulation 2005;111:1738-46) mostro la evidencia de correlaciones entre
las mutaciones SCN5A y la expresion de las conexinas en un modelo de ratones
transgenicos. De este modo, resulta razonable considerar al menos en parte,
que el intervalo H-V prolongado y los patrones tipo BRD observados en el SBr
son el resultado de un retraso de la conduccion por tiempo excesivo del
remodelado estructural (probablemente secundario a la mutacion SCN5A) en el
ventriculo derecho. Tales anormalidades estructurales pueden ser parte de
las explicaciones para la TV/FV fatal y la base para la terapia de ablacion.
Saludos,

Li Zhang

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English - Spanish

Ayerza et al, showed a case (Ayerza MR, de Zutter M, Goethals M, et al.
Heart transplantation as last resort against Brugada syndrome. J Cardiovasc
Electrophysiol 2002; 13: 943-944. report the first case of a patient with
BrS)  who required heart transplantation to control multiple "electrical
storms". The patient had ventricular normal imaging studies but was found to
have fat and severe fibrosis on the right ventricle in subsequently
reported. (Arthur. Wilde, personal communication). BrS or ARVC/D?????. Heart
transplantation  is indicated in patients with ARVC/D who develop severe
intractable ventricular failure. The activation sequence in the Heart of a
BrS patient was recently studied An explanted heart from a patient with BrS
undergoing cardiac transplantation. The explanted heart was perfused
according to Langendorff at 37 C with a blood –Tyrode’s mixture. Ninety-six
unipolar electrode terminals (attached to inflatable balloons) were used to
record electrical activity from the left and right endocardium, including
the septal walls.
Another 98 electrode terminals embedded in a sock-electrode were used to
record from the epicardium of both ventricles. Recordings were made during
constant pacing and programmed stimulation from AV-nodal region. A 3D image
of the activation pattern was constructed using MATLAB the computation and
POV-Ray for rendering. It shows the endocardial balloons with the
electrodes, and the epicardial sock electrode in a transparent schematic
image of the heart. Colored lines indicate isochrones (with 10 ms intervals)
in a scale form orange (early, 20 ms after stimuli artifact) to purple
(late, 150 ms). The experiment showed that RBBB pattern in BrS is correlated
with conduction slowing in the RVOT. .  (Linnenbank AC, Coronel R, Bakker
JMT. Heart Lung Center Utrecht, Utrecht, The Netherlands. Non-publishing
dates). This experience is coincident with my VCGs in BrS(Riera AR, Ferreira
C Schapachnik E, value of 12 lead electrocardiogram and derived
methodologies in the diagnosis of Brugada disease”. Chapter 7 . pp; 87-110.
In the Brugada syndrome from bench to bedside. Editor Charles Antzelevich
with associate editors Pedro Brugada, Joseph Brugada and Ramσn Brugada –
2005 - Blackwell – Futura “) we showed that in most cases of BrS, the
dromotropic disorder occurs in the region of the RV free wall, after the
division of the right bundle branch trunk, unlike most cases of CRBBB, third
degree or advanced right block, where the block topographically occurs
before the right branch division or in the right His, or in the membranous
portion, or in the moderator band, before reaching the RV tip in the base of
the papillary muscle of the tricuspid valve, i.e. the great majority of
CRBBB are PRE-DIVISIONAL. The block is situated in the right His or in the
main right bundle branch while in the great majority of Brugada syndromes
the block is POST-DIVISIONAL, right in the free wall, particularly in the
superior or subpulmonary division of the right branch, located in the
outflow tract of this branch. So the depolarization is totally different
between Brugada syndrome and CRBBB.
Best
Andrιs Ricardo Pιrez

-----------------------------

Ayerza y cols., mostraron un caso (Ayerza MR, de Zutter M, Goethals M, et
al. Heart transplantation as last resort against Brugada syndrome. J
Cardiovasc Electrophysiol 2002; 13: 943-944. report the first case of a
patient with BrS), que requirio transplante cardiaco para controlar
multiples "tormentas electricas". El paciente tenia estudios de imagenes
ventriculares normales, pero se encontro que presentaba adiposidad y
fibrosis grave en el ventriculo derecho. (Arthur. Wilde, personal
communication) SBr o M/DAVD???? Se indica transplante cardiaco en pacientes
con M/DAVD que desarrollan insuficiencia ventricular grave intratable. La
secuencia de activacion en el corazon del paciente con SBr, se estudio
recientemente en un corazon explantado de un paciente con SBr que se sometio
a transplante cardiaco. El corazon explantado se perfundio segun Langendorff
a 37 C con una mezcla de sangre con solucion de Tyrode. Noventa y seis
terminales de electrodos unipolares (unidas a balones inflables) se
emplearon para registrar la actividad electrica del endocardio derecho y del
izquierdo, incluyendo las paredes septales.

Otras 98 terminales de electrodos empotradas en un portaelectrodo se
emplearon para hacer un registro desde el epicardio de ambos ventriculos.
Los registraron se realizaron durante una estimulacion constante y
estimulacion programada de la region del nodo AV. Se construyo una imagen en
3D del patron de activacion empleando MATLAB para computar y POV-Ray para el
resultado. Muestra los balones endocardicos con los electrodos, y el
electrodo en el portaelectrodo epicardico en una imagen esquematica
transparente del corazon. Las lineas coloreadas indican isocrones (con
intervalos de 10 ms) en una escala desde el naranja (temprano, 20 ms luego
de interferencia de estimulo) hasta celeste (tarde, 150 ms). El experimento
mostro que el patron de BRD en el SBr se correlaciona con el enlentecimiento
de la conduccion en el TSVD (Linnenbank AC, Coronel R, Bakker
JMT. Heart Lung Center Utrecht, Utrecht, The Netherlands. Non-publishing
dates). Esta experiencia coincide con mis VCGs en el SBr (Riera AR,
Ferreira
C Schapachnik E, value of 12 lead electrocardiogram and derived
methodologies in the diagnosis of Brugada disease". Chapter 7 . pp; 87-110.
In the Brugada syndrome from bench to bedside. Editor Charles Antzelevich
with associate editors Pedro Brugada, Joseph Brugada and Ramσn Brugada -
2005 - Blackwell - Futura"). Demostramos que en la mayoria de los casos de
SBr, el trastorno dromotropico ocurre en la region de la pared libre del VD,
luego de la division del tronco de la rama derecha, a diferencia de muchos
casos de BCRD, bloqueo de tercer grado o avanzado de rama derecha, donde el
bloqueo topograficamente ocurre antes de la division de la rama derecha o en
el His derecho, o en la porcion membranosa, o en la banda moderadora, antes
de alcanzar la punta del VD en la base del musculo papilar de la valvula
tricuspide, es decir, la gran mayoria de BCRD y PREDIVISIONALES. El bloqueo
se situa en el His derecho o en la rama derecha principal, mientras que en
la gran mayoria de sindromes de Brugada, el bloqueo es POSTDIVISIONAL, justo
en la pared derecha, especialmente en la division superior o subpulmonar de
la rama derecha, localizado en el tracto de salida de esta rama. Por lo
tanto, la despolarizacion es totalmente diferente entre el sindrome de
Brugada y el BCRD.

Saludos,

Andrιs Ricardo Pιrez