[SCD-FORUM] 20E RE: Palpitations and SCD risk. Dr. Perez Riera

[SCD Symposium]

Dr. Andriy Vorotniak from Buenos Aires, Argentina. Here Andres Ricardo
Perez Riera from SP Brazil.


THE INCIDENCE OF SUPRAVENTRICULAR ARRHYTHMIAS IN THE BRUGADA SYNDROME

Sinus rhythm is the usual; however, Brugada syndrome (BrS) patients  
exhibit an abnormally high proportion of atrial arrhythmias that are
found in 10 to 25% of cases since the arrhythmogenic substrate is  
not  limited to the ventricles. In the original discovery by the Brugada
brothers (1992)(1), temporary AF was mentioned, as well as by authors  
from Brazil (2) and from Japan (3).  The latter mentioned that the  
paroxysmal form
of AF is observed in a 30% of cases.

A publication by Eckardt L et al (2001) (4), indicates a frequency  
for supraventricular arrhythmias of 29%. These authors described  
episodes of
AV supraventricular tachycardia with reentry.

There are references of Wolff-Parkinson-White syndrome A type   
associated to BrS (5-6).

There is a more advanced disease process in BrS patients with   
spontaneous atrial arrhytmias and ventricular inducibility was   
significantly related to a
history of atrial arrhythmias.The incidence  of atrial arrhythmias in  
patients with a spontaneous electrocardiogram  of BrS was 26% vs 10%  
in patients with a
flecainide-induced ECG.In patients with an indication of ICD, the  
incidence of atrial arrhythmias reached 27% vs 13% in patients with  
BrS but without ICD indication;

Inappropriate shocks due to atrial arrhythmias episodes were observed  
in 14% of ICD patient's vs 10.5% of appropriate shocks;

The implantation of a single-chamber device is as an independent  
predictive factor of inappropriate ICD discharges;

Careful programming of single-chamber ICD should be recommended to  
avoid inappropriate discharges in patients with BrS (7).

Arrhythmia of atrial origin was the only spontaneous pathologic  
rhythmic observed in a 46 years old man patient with BrS by Boveda et  
al (8).
Consequently it led to reconsider its prevalence in patients  
presenting this syndrome both in the literature and according  
Boveda's time  personal experience.

A 41-year-old man with BrS and no previous episodes of aborted SCD or  
syncope referred to local emergency room for an episode of  
symptomatic  AF. Blood chemistry
results showed hypokalemia(2.9 mEq/L). The other parameters were  
within the normal range. After few minutes, an episode of VF treated  
with biphasic DC shock 150 J
  occurred. In successive 2  hours, the patient experienced recurrent  
episodes of VT and VF. Each  biphasic DC shock 150 J was effective to  
restore sinus rhythm. No
further episodes occurred after normalization of serum levels of   
potassium. Before discharge, an ICD was inserted to prevent SCD.
Hypokalemia increases the risk of arrhythmic events in BrS (9).  
Hypokalemia increases the risk of arrhythmic events in BrS(10).

Sinus node dysfunction (SND)  is not a rare concomitant disorder in  
BrS and there is a possible genetic connection. SND is associated  
with AF(11).


References

1) Brugada P, Brugada J. Right bundle branch block, persistent ST
segment elevation and sudden cardiac death: A distinct clinical and
electrocardiographic syndrome. J Am Coll Cardiol 1992, 20: 1391-1396

2) Villacorta H, Faig Torres RA, SimF5es de  Castro IR, Lambert H. de
Araujo Gonzales Alonso R.: Morte subita em paciente com bloqueio de
ramo direito e elevacao persistente do segmento ST. Arq  Bras  
Cardiol. 1996; 66:( N4) 229-231

3) Itoh H, Shimizu M, Ino H, et al. Hokuriku Brugada Study Group.
Arrhythmias in-patients with Brugada-type electrocardiograph findings.
Jpn Circ J 2001; 65:483-6

4) Eckardt L, Kirchhof P, Loh P, et al. Brugada Syndrome and
Supraventricular Tachyarrhythmias: A Novel Association? J Cardiovasc
Electrophysiol 2001; 12:680-685

5) Eckardt L, Kirchhof P, Johna R, Haverkamp W, Breithardt G, Borggrefe
M. : Wolff-Parkinson-White syndrome associated with Brugada syndrome.
Pacing Clin Electrophysiol 2001;24(9 Pt 1):1423-4.

6) Bodegas AI, Arana JI, Vitoria Y, Arriandiaga JR, Barrenetxea JI.  
Brugada syndrome in a patient with accessory pathway. Europace 2002;  
4:87-9

7) Bordachar P, Reuter S, Garrigue S, Cai X, Hocini M, Jais P,  
Haissaguerre M, Clementy J. Incidence, clinical implications and  
prognosis of atrial arrhythmias in brugada syndrome.Eur Heart J.  
2004;25:879-884.

8) Boveda S, Combes N, Albenque JP, et al. Brugada syndrome and  
supraventricular arrhythmiasArch Mal Coeur Vaiss. 2004; 97: 688-692.

9) Notarstefano P, Pratola C, Toselli T, et al. Atrial fibrillation  
and recurrent ventricular fibrillation during hypokalemia in Brugada  
syndrome. Pacing Clin Electrophysiol. 2005; 28:1350-1353.

10) Notarstefano P, Pratola C, Toselli T, et al Atrial fibrillation  
and recurrent ventricular fibrillation during hypokalemia in Brugada  
syndrome.

11) Sumiyoshi M, Nakazato Y, Tokano T,  Sinus node dysfunction  
concomitant with Brugada syndrome. Circ J. 2005; 69:946-950.

All the best

Andrés Ricardo Pérez Riera
Chief of Electro-Vectocardiology Sector of the Discipline of Cardiology,
ABC Faculty of Medicine (FMABC), Foundation of ABC (FUABC)
- Santo André -  São Paulo - Brazil.
Rua Sebastião Afonso  885 - Zip Code: 044417-100- Jardim Miriam  S.P  
Brazil-


--
Dr. Sergio Dubner
President of Scientific Committee

Dr. Edgardo Schapachnik
President of Steering Committee




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