[SCD-FORUM] 79E RE: Brugada's pattern detection in a son of SCD's patient. Dr. Dubner
SCD Symposium
info at scd-symposium.org
Sat Oct 21 19:21:21 ART 2006
Dear Cagnolatti:
Very interesting question that Ramon Brugada already answered it. I
am sure we will listen some other oppinon about it, either from
Pedro and Josep or Silvia and her group.
On the other hand, evidence emerging from the study of fibrillation
both in the atria and the ventricle suggests an important role for
triggers arising from the Purkinje network or the RVOT in the
initiation of VF. Initial experience in patients with IVF and even
those with VF associated with LQTS Brugada syndrome and genuine
Idiopathic VF suggests that long term suppression of recurrent VF may
be feasible by the elimination of these triggers. With the
development of new mapping and ablation technologies, and greater
physician experience, catheter ablation of VF, with the ultimate aim
of curing such patients at risks of SCD, may not be an unrealistic
goal in the future (2).
Haissaguerre et al(3), localized by mapping the earliest endocardial
activity and by focal radiofrequency ablation of PTV/VF in three
patients with Brugada Syndrome. The authors conclude that triggers
from the Purkinje arborization or the RVOT have a crucial role in
initiating VF associated with Brugada syndrome and LQTS. These can be
eliminated by focal radiofrequency ablation.
In a highly symptomatic 18-year-old-male with BS, frequent episodes
of VF, fast PVT, and fast S-MVT were observed. The episodes were
classified as VT or VF and as a consequence received appropriate
therapies with the ICD. Precipitating VPBs that were stored in the
ICD memory and on the electrocardiogram (ECG) exhibited the same
morphology as frequent isolated VPBs. During the PES, right and left
atrial tachycardia with one-to-one atrioventricular conduction were
induced and successfully ablated.
VF was ablated using the same noncontact mapping (NCM) system-
triggering VPBs from RVOT(4).
Yu e al (5) presented a case of recurrent syncope diagnosed as
recurrent VF by an implanted loop recorder (ILR). The VF was
eliminated by RFCA of triggering ventricular premature complexes (VPCs).
The characteristics of VT in the BrS are: very fast polymorphic
ventricular tachycardia (PVT) is frequent (from 260 to 352bpm), with
very short onset extrasystole coupling (388 +/- 28msec), generally
preceded by premature ventricular contractions (PVCs) that are
identical to the beating that starts IPVT (6)
Spontaneous episodes of VF in patients with BrS are triggered by
specific PVCs (7)
Arrhythmic events occur in 93% of the cases during sleep or at dawn
in 92% of the cases when the patients present significant ST segment
elevation. It has been well established that the degree of ST segment
elevation is responsible for arrhythmias. A loss of phase 2 or PAT
dome in the RV epicardium (where the onset potassium outward Ito
current is more prominent) and not in the endocardium, causes ST
segment elevation. The normal heterogeneity existing between the
epicardium and the endocardium is increased in this entity, leading
to repolarization abnormalities in ECG and to a greater possibility
of arrhythmia by the mechanism called phase 2 reentry.
These forms resemble the very fast torsades de pointes (TdP) observed
in patients with normal QTc; nevertheless, there are clear
differences between both atypical tachyarrhythmias.
Observation:
Only in exceptional cases, bursts of
spontaneous Monomorphic Idiopathic Ventricular Tachycardia (MIVT) may
happen (8); however, the monomorphic form of VT is observed only when
induced by drugs. There are references about S-MVT appearance after
the administration of ajmaline, because the drug increases
heterogeneity even more in ventricular thickness repolarization(9).
There is a reference of incessant monomorphic ventricular tachycardia
during febrile illness in a patient with BrS (10).
An automatic mechanism mediated by the beta-receptor seems to hold
an important role in the S-MVTs that originate in the RVOT. The place
of origin of the event could be very near to the lesion that causes
ST elevation(11). In these cases in which monomorphic ventricular
tachycardia (MVT) is inducible by drugs, an automatic mechanism is
pointed out as electrophysiological substrate, produced in an
activity focus triggered by late after-depolarization located in the
RVOT (12).
Warmest regards,
Sergio Dubner and Andres Ricardo Perez Riera
References
1) McGregor M, Chen J. Should the implantable cardiac
defibrillator be used for primary prevention of sudden death? A
review of the issues relevant to hospital decision making. Can J
Cardiol. 2004; 20:1199-1204.
2) Sanders P, Hsu LF, Hocini M, et al. Mapping and ablation of
ventricular fibrillation.Minerva Cardioangiol. 2004; 52:171-181.)
(Weerasooriya R, Hsu LF, Scavee C, et al. Catheter Ablation of
Ventricular Fibrillation in Structurally Normal Hearts Targeting the
RVOT and Purkinje Ectopy. Herz. 2003; 28:598-606.
3) Haissaguerre M, Extramiana F, Hocini M, et al. Mapping and
ablation of ventricular fibrillation associated with long-QT and
Brugada syndromes. Circulation. 2003; 108:925-928.
4) Darmon JP, Bettouche S, Deswardt P, et al. Radiofrequency
Ablation of Ventricular Fibrillation and Multiple Right and Left
Atrial Tachycardia in a Patient with Brugada Syndrome. J Interv Card
Electrophysiol. 2004; 11:205-209.
5) Yu CC, Tsai CT, Lai LP, Lin JL. Successful radiofrequency
catheter ablation of idiopathic ventricular fibrillation presented as
recurrent syncope and diagnosed by an implanted loop recorder. Int J
Cardiol. 2006;110:112-3.
6) Kakishita M, Kurita T, Matsuo K, et al. Mode of onset of
ventricular fibrillation in patients with Brugada syndrome detected
by implantable cardioverter defibrillator therapy. J Am Coll Cardiol
2000; 36:1646-1653.
7) Gang ES, Priori SS, Chen PS. Short Coupled Premature
Ventricular Contraction Initiating Ventricular Fibrillation in a
Patient with Brugada Syndrome. J Cardiovasc Electrophysiol. 2004;
15:837.
8) Sastry BK, Narasimhan C, Soma Raju B. Brugada syndrome with
monomorphic ventricular tachycardia in a one-year-old child. Indian
Heart J 2001; 53:203-205.
9) Pinar Bermudez E, Garcia-Alberola A, Martinez Sanchez J, et.
al.: Spontaneous sustained monomorphic ventricular tachycardia after
administration of ajmaline in a patient with Brugada syndrome. Pacing
Clin Electrophysiol 2000; 23:407-409.
10) Dinckal MH, Davutoglu V, Akdemir I, Soydinc S, Kirilmaz A,
Aksoy M.
Incessant monomorphic ventricular tachycardia during febrile illness
in a patient with Brugada syndrome: fatal electrical storm. Europace.
2003; 5:257-61.
11) Shimada M, Miyazaki T, Miyoshi S, et al. Sustained monomorphic
ventricular tachycardia in a patient with Brugada syndrome. Jpn Circ
J 1996; 60: 364-370,
12) Ogawa M, Kumagai K, Saku K. Spontaneous right ventricular
outflow tract tachycardia in a patient with Brugada syndrome. J
Cardiovasc Electrophysiol 2001; 12:838-840.
Sergio J. Dubner, MD, FACC
Director Arrhythmias and
Electrophysiology Service
Clinica y Maternidad Suizo Argentina
Arenales 2463 3 A
1124 Buenos Aires - Argentina
--
Dr. Sergio Dubner
President of Scientific Committee
Dr. Edgardo Schapachnik
President of Steering Committee
El 20/10/2006, a las 12:26, SCD Symposium escribió:
> Forum of the ISHNE Sudden Cardiac Death World-Wide Internet Symposium
> ______________________________________________________________________
>
> Medtronic ICDs with world-leading features:
> http://www.medtronic.com/physician/tachy/
> ______________________________________________________________________
>
> Dear Sergio,
> About a case of reanimation of sudden death in a 54-year-old
> patient, with no structural heart disease, with all the studies
> made: coronary angiography, MNR, Holter, EPS.
> Everything appears to be normal. Monomorphic arrhythmic storm is
> detected at the moment the patient is admitted. The patient is
> provided life support and he recovers in 24 hs. ICD implantation is
> decided. After three months he displays three shocks by arrhythmic
> storm, incessant ventricular tachycardia. Mapping and focus
> ablation is decided, in outflow tract with mismatch.
> To this moment, the patient has not displayed any event. It's been
> three months, and in a Holter register in one of his sons, typical
> Brugada pattern is observed. The patient is 17 years old,
> asymptomatic. I cannot perform pharmacological test. What should I
> do next?
>
> Dr. Cagnolatti <drcagnolattia at hotmail.com>
>
> --
> Dr. Sergio Dubner
> President of Scientific Committee
>
> Dr. Edgardo Schapachnik
> President of Steering Committee
>
>
>
>
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