<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><DIV><FONT class="Apple-style-span" face="Arial">Dear Cagnolatti: </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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).</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">VF was ablated using the same noncontact mapping (NCM) system-triggering VPBs from RVOT(4).</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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).</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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)</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Spontaneous episodes of VF in patients with BrS are triggered by specific PVCs (7)</FONT></DIV><P align="justify"><FONT class="Apple-style-span" face="Arial">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.</FONT></P><P align="justify"><FONT class="Apple-style-span" face="Arial">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.</FONT></P><DIV><FONT class="Apple-style-span" face="Arial">Observation:</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"> 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). </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"> 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). </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Warmest regards,</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"> </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Sergio Dubner and Andres Ricardo Perez Riera</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"> </FONT></DIV><P align="justify"><FONT class="Apple-style-span" face="Arial"> References</FONT></P><DIV><FONT class="Apple-style-span" face="Arial"> </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">10) Dinckal MH, Davutoglu V, Akdemir I, Soydinc S, Kirilmaz A, Aksoy M.<BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"> Incessant monomorphic ventricular tachycardia during febrile illness in a patient with Brugada syndrome: fatal electrical storm. Europace. 2003; 5:257-61.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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,</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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.</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Sergio J. Dubner, MD, FACC</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Director Arrhythmias and</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Electrophysiology Service</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Clinica y Maternidad Suizo Argentina</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Arenales 2463 3 A</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">1124 Buenos Aires - Argentina</DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT><DIV><DIV><FONT class="Apple-style-span" face="Arial">--</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Sergio Dubner</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Scientific Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Edgardo Schapachnik</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Steering Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR class="Apple-interchange-newline"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT><DIV><DIV><FONT class="Apple-style-span" face="Arial">El 20/10/2006, a las 12:26, SCD Symposium escribió:</FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR class="Apple-interchange-newline"></FONT><BLOCKQUOTE type="cite"><DIV><FONT class="Apple-style-span" face="Arial">Forum of the ISHNE Sudden Cardiac Death World-Wide Internet Symposium</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">______________________________________________________________________</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Medtronic ICDs with world-leading features:</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><A href="http://www.medtronic.com/physician/tachy/">http://www.medtronic.com/physician/tachy/</A></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">______________________________________________________________________</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV> <DIV><FONT class="Apple-style-span" face="Arial">Dear Sergio,</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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. </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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. </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">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? </FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Cagnolatti <<A href="mailto:drcagnolattia@hotmail.com">drcagnolattia@hotmail.com</A>></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT><DIV><DIV><FONT class="Apple-style-span" face="Arial">--</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Sergio Dubner</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Scientific Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Edgardo Schapachnik</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Steering Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR class="Apple-interchange-newline"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT><DIV><FONT class="Apple-style-span" face="Arial">_______________________________________________</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Scd-forum mailing list</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><A href="mailto:Scd-forum@scd-symposium.org">Scd-forum@scd-symposium.org</A></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><A href="http://www.grupoakros.com.ar/mailman/listinfo/scd-forum">http://www.grupoakros.com.ar/mailman/listinfo/scd-forum</A></FONT></DIV> </BLOCKQUOTE></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></BODY></HTML>