[ARVD-FORUM] ECG with modified protocol. Dr. Marquez

Tue Apr 5 19:33:32 ART 2005

English - Spanish

Dear Dr. Perez Riera and colleagues,
Let me make some notes regarding modified ECGs.

1. I agree with Dr. Marcus in that the leads we should amplify (double
velocity, double voltage) to see the epsilon wave are V1 to V3.
2. On occasions, double velocity makes it difficult to interpret ECG and it
also would be convenient to have an ECG with standard velocity and double
voltage.
3. High precordial leads can also be useful to be able to see an epsilon
wave.
4. The lead originally described by Lian is: right arm below sternal wishbone 
and left arm in the 5th right intercostal space and parasternal line. With 
this electrode position leads I, II, and III must be recorded. Someone has 
said that these are Fontaine leads, but they actually were described by Lian 
in the 50's. To avoid confusions, maybe we should call them LI, LII, and 
LIII.
5. The lead that is original from Fontaine is the use of the left leg
electrode on the precordial region at V4 level. Anyway, leads I, II, and III
are recorded; which may as well be called FI, FII, and FIII.

Best regards,

Dr. Manlio F. Márquez
Departamento de Electrocardiología
Instituto Nacional de Cardiología "Ignacio Chávez"
México, D.F.

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

Estimado Dr. Perez Riera y colegas, me permito hacer
algunas anotaciones pertinentes a los ECG modificados.

1. Concuerdo con el Dr. Marcus en que las derivaciones que debemos amplificar 
(doble velocidad, doble voltaje) para ver la onda epsilón son V1 a V3.
2. En ocasiones la doble velocidad hace difícil interpretar el ECG y también 
sería conveniente contar con un ECG a velocidad estándar y doble voltaje.
3. Las derivaciones precordiales altas también pueden ser de utilidad para 
poder apreciar una onda epsilón
4. La derivación descrita originalmente por Lian es: brazo derecho por debajo 
de horquilla esternal y brazo izquierdo en 5° espacio intercostal derecho y 
línea paraesternal. Con esta posición de electrodos se deben registrar las 
derivaciones I, II y III. Alguien ha dicho que estas son las derivaciones de 
Fontaine pero en realidad fueron descritas por Lian en los años 50's. Para 
evitar confusiones tal vez deberiamos llamarlas LI, LII y LIII.
5. La derivación que sí es original de Fontaine es el empleo del electrodo de 
la pierna izquierda sobre la región precordial a nivel de V4. Igualmente se
registran las derivaciones I, II y III que bien pudieran llamarse FI, FII y 
FIII.

Cordialmente

Dr. Manlio F. Márquez
Departamento de Electrocardiología
Instituto Nacional de Cardiología "Ignacio Chávez"
México, D.F.

>
> English - Portuguese
>
> ECG with modified protocol
>
> 1)       Rhythm strips should be obtained of the precordial leads V1-V6 at
> double speed (50mm/s) and double amplitude (20mm/mv) in order to compare
> the duration of the QRS complex (QRSD) in different leads as well as to
> record the epsilon wave;
>
> 2)       Rhythm strips should be obtained of leads DI-aVF at double speed
> (50mm/s) and double amplitude (20mm/mv). Place the left arm lead over the
> xyphoid process, the right arm lead on the manubrium sternum and the left
> leg lead over a rib at the V4 or V5 position in order to elicit the epsilon
> wave.
>
> Localized prolongation of QRSD interval in V1-V3 / QRSD interval in V4-V6 >
> than 1.2 has been found in 97% of cases of ARVC/D. The QRSD is correlated
> with the amount of fibrous tissue in patients with VT of RV origin The
> sensitivity of this QRS diagnostic criterion has not been established in
> patients who do not have overt manifestation of this disease. The
> specificity of this criterion has not been completely established yet in
> patients without this entity. In Brurga Syndrome QRS  > 110 ms in V1, V2 or
> V3. It is possible. There is a paper showing that BrS may also present
> prolongation in QT interval duration from V1 to V3 and consequently
> prolongation of the QTc interval in the right precordial leads.  (Pitzalis
> MV, Anaclerio M, Lacoviello M, et al. QT-interval prolongation in right
> precordial leads: an additional electrocardiographic hallmark of Brugada
> syndrome. J Am Coll Cardiol. 2003; 42:1632-1637  ). If the QT interval is
> prolonged only from V1 to V3, being normal from V4 to V6, it is clear that
> this increase may be due to prolongation of ventricular depolarization (QRS
> complex) and/or by ST/T prolongation (repolarization). If we admit that in
> Brurgada Syndrome there is some degree of branch block, clearly the QT
> interval prolongation is due partly to this. The QTc interval constitutes
> the classical measurement for ventricular repolarization; however, this
> parameter includes ventricular depolarization (QRS), and therefore
> represents the so-called electric systole, which includes depolarization
> (QRS) and ventricular repolarization (ST/T = JT interval). Thus, when there
> is branch block (as in the some cases of Brugada syndrome), the measurement
> of ventricular repolarization through QTc may be incorrect. In these cases,
> the measurement of the JT interval (JT = QT - QRSD) is more accurate than
> the QT interval, because it excludes the depolarization that is found
> prolonged, because the biventricular chamber activates sequentially and not
> concomitantly as normally. This is the reason why it is essential to know
> accurately the exact point where depolarization ends and repolarization
> begins.
>
> Best regard
>
> Andrés Ricardo Pérez Riera
>
> --------------------------------------------------------
>
> Português
>
> ECG com protocolo modificado
>
> 1) 	A tira  das precordiais de V1-V6 realizadas a dupla velocidade de
> 50mm/s e dupla voltagem (20mm/mV) para comparar a duração do QRS nas
> diversas derivacoes e para tentar observar a onda epsilon. Colocar o
> eletrodo do braço esquerdo sobre a apéndice xifoides o do braço direito no
> manubrio do esterno e o eletrodo  da perna esquerda sobre a costela na
> posição de V4 or V5 para tentar observar a onda epsilon.
>
> 2)       A tira deveria se obter en DI e aVL (50mm/s) a dupla velocidade e
> a dupla voltagem (20mm/mv).
>
> Prolongamento localizado de V1 a V3 com relação V1-V2-V3/ V4-V5-V6 > 1.2 ha
> sido encontrado em 97% dos casos de DAVD. A duração do complexo QRS estaria
> relacionada com a quantidade de tecido fibroso. A especificidade de este
> critério não ha sido determinada, todavia  em pacientes sem esta entidade.
>
> Na síndrome de Brugada QRS  > 110 ms em V1, V2 ou V3 é posível. Há uma
> publicação mostrando prolongamento do QT de V1 aV3 e consequente aumento do
> intervalo QTc nas precordiais direitas no Brugada (Pitzalis MV, Anaclerio
> M, Lacoviello M, et al. QT-interval prolongation in right precordial leads:
> an additional electrocardiographic hallmark of Brugada syndrome. J Am Coll
> Cardiol. 2003; 42:1632-1637). Se o intervalo QT está prolongado de V1 a V3
> e normal de V4 a V6 é claro que este aumento poderia ser dado por
> prolongamento da despolarização ventricular (QRS) e ou por prolongamento do
> ST/T (repolarização) Se nos admitimos que na sindrome de Brugada há algum
> grau de bloqueio de ramo  claramente o prolongamento do intervalo QT é dado
> parcialmente por este.
>
> O intervalo QT constitui uma medida clássica da repolarizacao, porém, incli
> a despolarização ventricular (QRS)  e represente a chamada sístole elétrica
> a qual inclui despoarização (QRS)  e repolarização (ST/T = intervalo JT).
> Assim sendo, quando existe bloqueio de ramo (como acontece em alguns casos
> de sindrome de Brugada) a medida da repolarizaçao usando o intervalo QT
> pode ser incorreta. Nestes casos a medida do intervalo JT (JT = QT - QRSD)
> é mais precisa que a medida do intervalo QT porque excui a despolarizacao
> que esta prolongada porque a câmara biventricular  ativa-se em forma
> sequencial e não  concomitantemente. Esta é a razão porque é fundamental
> conehcer em forma exata em que ponto termina a despolarizacao e quando
> inicia a repolarizacao
>
> Saludações
>
> Andrés Ricardo Pérez Riera
>
> > English - Spanish
> >
> > Dear colleagues,
> > The questions and answers by the experts that are being distributed in
> > the Forum, deal with the management to follow with the relatives of the
> > patients.
> > Regarding this, I have noticed a subtle difference between the reply by
> > Dr. Frank Marcus to Dr. Laura Sanzani, and the reply by Dr. Perez Riera
> > to Dr. Martinez Rubio.
> > Dr. Andres includes in the algorithm of studies to be performed on these
> > relatives, the "ECG with modified protocol", which is not included
> > between the studies suggested by Dr. Marcus.
> > I ask the first one if he could explain what is this modified protocol
> > and what is its value in ARVD, and to Dr. Marcus, if he suggests
> > including it in the routine for the family members of the patients with
> > ARVD.
> >
> > Thanking you in advance,
> >
> > Jose Siringa
> >
> > -----------------------------------------
> >
> > Estimados colegas:
> > l;as preguntas y respuestas de los expertos que se estan distribuyendo en
> > el Foro, estan haciendo referencia a la conducta a seguirse con los
> > familiares de los pacientes.
> > En ese sentido he notado una sutil diferencia entre la respuesta que el
> > Dr. Frank Marcus le da a la Dra. Laura Sanziani, en relacion a la que el
> > Dr. Perez Riera utiliza para responderle al Dr. Martinez Rubio.
> > El Dr. Andres incluye en el algoritmo de estudios de estos familiares el
> > "ECG con protocolo modificado", que no figura entre los estudios
> > sugeridos por el Dr. Marcus.
> > Le pregunto al primero si puede explicar en qué consiste tal protocolo
> > modificado y que valor tiene en la ARVD y al Dr. Marcus, si sugiere
> > incluirlo en la rutina para los familiares de pacientes con ARVD.
> >
> > Gracias anticipadas
> >
> > Jose Siringa
>
> _______________________________________________
> Arvd-forum mailing list
> Arvd-forum at ishne.org
> http://www.ishne.org/mailman/listinfo/arvd-forum

-- 
Dr. Sergio Dubner
Director

Dr. Edgardo Schapachnik
Director