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1 ISSN VOL.11 NO.2 JUNE 2010 The Official Journal of Korean Society of Cardiac Arrhythmia Special Review Main Topic Reviews Conference Coverage ECG & EP Cases The Korean Society of Cardiac Arrhythmia

2 Journal of Cardiac Arrhythmia Copyright 2010 Journal of Cardiac Arrhythmia Editorial Board & MMK Co., Ltd. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without permission in written form from the copyright holder. This publication is published by MMK Co., Ltd., under continuing medical educational grant from Choongwae Pharma Corporation.

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5 Journal of Cardiac Arrhythmia Vol.11 No.2 June 2010 Contents Cover: The anterior fascicle of the left bundle at the surface and the intramyocardial right bundle. (page 8) Special Review Main Topic Reviews Conference Coverage ECG & EP Cases

6 SPECIAL REVIEW Ventricular Anatomy for the Electrophysiologist (Part II) ABSTRACT The conduction fibers and Purkinje network of the ventricular myocardium have their peculiar location and immuno-histochemical characteristics. The bundle of His is located at the inferior border of the membranous septum, where the single trunk ramifies into the left and right bundle branches. The left bundle branches are clearly visible at the surface. The right bundles are hidden in the septal myocardium and it is not easy to recognize them. The cellular characters of the conduction bundles are modified myocardial cells with less cytoplasmic filaments. Myoglobin is expressed at the contractile part, whereas CD56 is expressed at the intercalated disc. A fine meshwork of synaptophysin positive processes is noted particularly at the nodal tissue. C-kit positive cells are scattered, but their role is not well understood. Purkinje cells are a peripheral continuation of bundles seen at the immediate subendocardium of the left ventricle. Key words: conduction system Purkinje network pathology arrhythmia electrophysiology Introduction The functional assessment of abnormal cardiac rhythm and a targeted treatment based on electrophysiologic studies are successful advances in cardiology. 1 Morphological assessment or confirmation of hearts with such abnormalities is rare, not only due to the limited availability of human hearts but also inherent technological limitations of existing technology. 2 Classical morphological approaches and immuno-histochemical or molecular biologic assessment on a heart transplant recipient will be a unique chance to study the conduction system of the Correspondence: Jeong-Wook Seo, Department of Pathology, Seoul National University College of Medicine and Hospital, 103 Daehangno, Jongro-gu, Seoul , Korea Tel: , Fax: jwseo@snu.ac.kr * Kim MY is a senior student from Ewha Woman s University School of Medicine. human heart. In this brief review, the histological characteristics of conduction cells, stained by conventional and immuno-histochemical staining, are demonstrated in the second part of the review. 3 The characteristic location of the ventricular conduction system The atrioventricular node is situated in its subendocardial location at the triangle of Koch. A cluster of short spindle cells are arranged compactly around the AV nodal artery. The long axis of the AV node is approximately 0.7 cm. Fatty tissue and some nerve fibers are seen around the node. The bundle of His is 0.5~0.7 cm long and 0.1 cm in diameter (Figure 1, 2). The bundle has a short traversing segment to the anterior superior direction and then ramifies into the 6 Journal of Cardiac Arrhythmia

7 right and left bundles (Figure 2). The left bundle and its anterior and posterior fascicles are recognized histologically at the subendocardium of the left ventricular surface of the ventricular septum. The right bundle is located between the thick bundles of the right ventricular myocardium and the true septal myocardium. The histological verification of the right bundle is not easier than the left side. Masson trichrome staining is one of the convenient methods to differentiate the conduction tissue from collagenous stroma and pathologic fibrous changes of the myocardium are demonstrable as well through the trichrome staining (Figure 3). It is understood that bundles and fascicles are covered with fibrous sheath so that rapid conduction from the myocardium is insured, although electrical conduction between cells needs a special gab junction protein or intercalated disc as revealed by electron microscopy. Side to side contact by a parallel alignment of muscle bundles is not conductive. It is therefore important to have an axial alignment to propagate contractile stimulation. Histological and immuno-histochemical characteristics of the conduction system Cells of the conduction system are mainly myocardial cells. The cytoplasm contains myofibrils and they do not have cytoplasmic processes as seen in neural cells. The conduction cells have less myofibrils than myocardial cells and intimate contact with nerve endings are noted. Conduction cells at the microscopic level are spindle cells with smaller cytoplasm. The immuno-histochemical reaction against myoglobin is positive (Figure 3). The intensity of staining by immuno-histochemistry is often influenced by fixation and other factors so that visual intensity of staining may not be an indicator of the amount of protein. Neural cell adhesion molecule (NCAM, CD56) is a member of the immunoglobulin super family, mediating intercellular adhesion in the nervous system and skeletal muscle and CD56 was up-regulated at the ischemic myocardium in human and animal models. 4 There was a strong positive reaction for CD56 at the SPECIAL REVIEW MV RC NC MV Figure 1.Left ventricular surface of the ventricular septum. The initial cut was made at the commissure of right and noncoronary cusps (RC, NC) of the aortic valve. After that, 4 cm long tissue blocks, 2 cm above and below the aortic valve, were designed to make 9 pieces of vertical sections, each with 4 mm thickness (#1-9). Block #9 is toward the anterior wall of the left ventricle, while block #4 toward the posterior wall. The rest of the septal surface was sectioned horizontal to make blocks (#10-21). MV; mitral valve, NC; non-coronary cusp, RC; right coronary cusp VOL.11 NO.2 7

8 SPECIAL REVIEW A TT AV MV B HB TV TV C D INF AO HB RC TV Figure 2. A. histological section at piece #3 of Fig 1 showing the atrioventricular node (AV) over the fibrous annulus at the atrial surface. B. A section at piece #2 of Fig 1 showing the non-branching His bundle (HB) at the inferior border of the membranous septum, where the posterior fascicle (long open arrows) ramifies. C. A section at piece #1 of Fig 1 showing a non-branching bundle (HB), the anterior fascicle of the left bundle (long arrows) at the surface and the intramyocardial right bundle (short arrows). D. A section at piece #7 of Fig 1 showing the right part of the ventricular septum extending to the infundibulum (INF) of the right ventricle. Short arrows indicate the plane between myocardial layers where the right bundle is located (Masson s trichrome stain). AO; aorta, MV; mitral valve, RC; right coronary cusp of aortic valve, TT; tendon of Todaro, TV; septal leaflet of tricuspid valve intercalated disc of the ventricular myocardium (Figure 4). The atrioventricular node and bundles did not show such strong reaction. It is also noted that the length of myocytes represented as the length between two intercalated discs was longer at the subendocardial left bundles. Synaptophysin, another marker for neural cells is negative at the myocardial cells, but a fine meshwork of synaptophysin positive fibers is seen around the individual conduction cells. The staining pattern of synaptophysin at the atrial myocardium was a slender network between the myocytes (Figure 5). This pattern was the most prominent at the atrial myocardium and AV node. His bundle is faintly stained and ventricular myocardium is the weakest. C-Kit is known to be one of the markers of stem cells 5 and interstitial Cajal-like cells related with atrial arrhythmia. 6,7 The C-Kit positive cells were rare isolated cells at His bundle (Figure 5). Atrioventricular 8 Journal of Cardiac Arrhythmia

9 A B cs SPECIAL REVIEW PF PF LV Septum MC MC C D PF PF MC MC Figure 3. A. Histological section at piece #16 of Fig 1 showing a cross section of the distal part of the subendocardial left bundle forming Purkinje fibers (PF) (arrow) separated from the underlying myocardium (MC). B. A section at piece #16 of Fig 1 showing subendocardial smooth muscle nodules overlying left bundles (open arrow & dot line). C. A section at piece #1 of Fig 1 showing thick and continuous subendocardial smooth muscle fibers (open arrow & dot line) stained violet with Masson trichrome but appear negative for myoglobin as shown in D. (A~C; Masson s trichrome stain, D; Myoglobin) node has some, but rest of area show few positive cells. Previous studies on the conduction system of the heart showed subsarcolemmal SR (sarcoplasmic reticulum), but no T-tubule or corbular SR. Connexin 45 and neurofilament M (NF-M) were found, but connexin 43 and atrial natriuretic peptide were lacking. 1,8 Myocytes of the sinoatrial and atrioventricular (AV) nodes characteristically have small, dispersed gap junctions predominantly composed of Cx45. The His bundle co-expresses Cx45 with Cx43, while its downstream branches prominently express Cx40. Cx43 becomes abundant in the more distal portions of the system, while Cx45 is expressed continuously from the AV node to the ends of the Purkinje fibers. 9 Purkinje network The Purkinje fibers are part of the ventricular VOL.11 NO.2 9

10 SPECIAL REVIEW A B Figure 4. A. An intense positive reaction for CD56 at intercalated discs (arrows) of ventricular septal myocardial cells. B. A less intense positive reaction for CD56 at bundle branches (double head arrow) and long interval intercalated discs. A B Figure 5. A. The staining pattern of synaptophysin at atrial myocardium was a slender network between the myocytes. B. The staining pattern of C-Kit positive cells at His bundle. (x400) (A; Synaptophysin, B; C-kit) 10 Journal of Cardiac Arrhythmia

11 conduction system and were originally discovered by Tawara. 10,11 These fibers conduct excitation (electrical activation) rapidly from the bundle of His to the ventricular myocardial tissue. The Purkinje fibers are myocardial cells with vacuolated cytoplasm located in the ventricular walls of the heart, just beneath the endocardium. 12 Purkinje fibers, being modified myocardial cells, contain some contractile protein, but the amount is small and glycogen and other organelles occupy the cytoplasm. It has been argued that vacuolated Purkinje cells are only seen in the ungulate heart, but the vacuolated character is noted in human heart too. There are, however, muscular cells, smooth muscle cells, other than Purkinje fibers found in the subendocardium (Figure 3C), particularly in hearts with failure. From the point of view of ultrastructural composition, the cells of different parts of the cardiac conduction system are partly similar. In contrast to the heart contractile cardiomyocytes, the cells of the cardiac conduction system including Purkinje fibers have a small amount of myofibrils, small mitochondria, lighter cytoplasm and higher glycogen content, but no T-tubular system. The electrophysiologic demonstration of the Purkinje network showed a propagation of excitation starting from the apex, continuing rapidly towards the base of the ventricle resulting in a contractile motion from the apex to the base. 12 Another study using electromechanical wave imaging visually confirmed that artificially created sinus rhythm and right-atrial pacing, consisted of a contraction wave that started at the apex right at the beginning of the QRS complex, propagated along the septum and then the leftventricular posterior wall and finally to the base. 13 Ventricular pacing, on the other hand, revealed a disharmonized contraction of the ventricle, confirming that Purkinje fibers have a crucial role in the synchronization of ventricular contractions. 13 A richly trabeculated endocardium, in which the endocardial invaginations carry the Purkinje tissue partway into the left ventricular endocardium, further increases the speed and area of early ventricular activation. This is a factor in ventricular synchronous activation together with the distribution of the conduction branches and the rapid velocity of the conduction system. 16 Rapid ventricular arrhythmias in post-myocardial infarction in the canine heart arise from ectopic foci (triggered) within the Purkinje fiber network located in the subendocardium of the infarct zone in the left ventricle. These spontaneously occurring arrhythmias predictably occur between 24 to 48 hours after occlusion. In Purkinje cells dispersed from the subendocardium of the infarct zone (Purkinje cells from a 48-hour infarcted heart), the density and function of several sarcolemmal ion channels are altered compared to normal Purkinje cells. Little work has been done on remodeled Purkinje cells, particularly Purkinje cells involved in the initiation and perpetuation of cardiac arrhythmias in diseased hearts. 17 The Purkinje fibers are distinguished from heart muscle cells by a distinct pattern of gene expression. They up-regulate Cx42, a conduction cell-specific gap-junction protein, unique ion channels, and genes typically expressed in neuronal cells. In addition, conduction cells induce a unique set of myofibrillar protein genes, such as slow-twitch skeletal muscle myosin heavy chain (smyhc), atrial myosin heavy chain (amyhc), and skeletal muscle-type myosin binding protein-h (MyBP-H). Purkinje fibers also down-regulate heart muscle-specific myofibrillar proteins, such as troponin and myosin binding protein- C (cmybp-c), which are essential for normal heart muscle contractility. 14 Studies on experimental animals with ischemic heart disease demonstrate alteration in the distribution of gap junction immunolabel to the sides of the myocyte, called lateralization. Gap junction mediated passage of ionic/molecular signals appears responsible for the spread of the ischaemia-reperfusion injury from myocyte to myocyte that leads to rigour contracture and cell death. Gap junction channels are almost absent in the sinus node, there are few of them in the AV node, but there are a lot of them in fast conducting muscle cells such as His and Purkinje fibers. This gives rise to the anisotropic propagation of depolarization along the SPECIAL REVIEW VOL.11 NO.2 11

12 SPECIAL REVIEW cardiac muscle fiber orientation. 15 Heterogeneity of gap junction distribution combined with reduced Cx43 levels appears to act cooperatively to create an arrhythmogenic substrate at less severe levels of overall gap junction reduction than predicted in theoretical models. The findings in mouse models lend considerable support to the view that the nature and extent of the Cx43 reduction in the failing human ventricle is, in practice, of sufficient magnitude to increase susceptibility to arrhythmia. 9 The Cx43 gap junction arrangement is particularly disordered in hypertrophic cardiomyopathy, the most common cause of sudden cardiac death due to arrhythmia in young adults. In cardiac-restricted Cx43 knockout mice selected for longer term survival, reduction of coupling resulting from declining ventricular Cx43 leads to propagation of the impulse across numerous Purkinje/ working ventricular myocyte junctions that normally remain dormant, thereby creating abnormal activation patterns and wave-front collisions in the ventricular myocardium. Conclusion It is important that the His bundle and the left bundle branches form a continuum with the distal part of the ventricular conduction system, named the Purkinje network. This will allow myocardial contraction to begin from the apex after the activation of the Purkinje network. The key morphological feature of Purkinje fibers in ungulate hearts is vacuolated cytoplasm, which is a manifestation of small numbers of contractile elements and a large amount of glycogen. Molecular characterization of the activity of connexin 43 is one of the important factors involved in arrhythmias in heart failure, myocardial infarcts and hypertrophic cardiomyopathy. References 1. Boyett MR, Dobrzynski H. The sinoatrial node is still setting the pace 100 years after its discovery. Circ Res. 2007;100: Anderson RH, Yanni J, Boyett MR, Chandler NJ, Dobrzynski H. The anatomy of the cardiac conduction system. Clin Anat. 2009;22: Seo J-W. Ventricular Anatomy for the Electrophysiologist (Part I) Gattenlohner S, Waller C, Ertl G, Bultmann BD, Muller-Hermelink HK, Marx A. NCAM (CD56) and RUNX1(AML1) are up-regulated in human ischemic cardiomyopathy and a rat model of chronic cardiac ischemia. Am J Pathol. 2003;163: Stamm C, Liebold A, Steinhoff G, Strunk D. Stem cell therapy for ischemic heart disease: beginning or end of the road? Cell Transplant. 2006;15(suppl 1):S47-S Morel E, Meyronet D, Thivolet-Bejuy F, Chevalier P. Identification and distribution of interstitial Cajal cells in human pulmonary veins. Heart Rhythm. 2008;5: Kostin S, Popescu LM. A distinct type of cell in myocardium: interstitial Cajal-like cells (ICLCs). J Cell Mol Med. 2009;13: Baruscotti M, Robinson RB. Electrophysiology and pacemaker function of the developing sinoatrial node. Am J Physiol Heart Circ Physiol. 2007;293:H Severs NJ, Bruce AF, Dupont E, Rothery S. Remodelling of gap junctions and connexin expression in diseased myocardium. Cardiovasc Res. 2008;80: Silverman ME, Hollman A. Discovery of the sinus node by Keith and Flack: on the centennial of their 1907 publication. Heart. 2007;93: James TN. The development of ideas concerning the conduction system of the heart. Ulster Med J. 1982;51: Ijiri T, Ashihara T, Yamaguchi T, Takayama K, Igarashi T, Shimada T, Namba T, Haraguchi R, Nakazawa K. A procedural method for modeling the purkinje fibers of the heart. J Physiol Sci. 2008;58: Konofagou EE, Luo J, Saluja D, Cervantes DO, Coromilas J, Fujikura K. Noninvasive electromechanical wave imaging and conduction-relevant velocity estimation in vivo. Ultrasonics. 2010;50: Takebayashi-Suzuki K, Pauliks LB, Eltsefon Y, Mikawa T. Purkinje fibers of the avian heart express a myogenic transcription factor program distinct from cardiac and skeletal muscle. Dev Biol. 2001;234: Kanj M, Saliba W. Basic arrhythmia physiology mechanisms. In: Natale A, Wazni O, eds. Handbook of cardiac electrophysiology. London: Informa; Boineau JP. Left ventricular muscle band (VMB): thoughts on its physiologic and clinical implications. Eur J Cardiothorac Surg. 2006;29(suppl 1):S56-S Boyden PA, Hirose M, Dun W. Cardiac Purkinje cells. Heart Rhythm. 2010;7: Journal of Cardiac Arrhythmia

13 MAIN TOPIC REVIEWS Overview of sudden cardiac death in Korea (Out-of-hospital cardiac arrest) ABSTRACT In Korea, sudden cardiac death (SCD) is a major cause of death. But the incidence of SCD has been underestimated. Recently, the cardiac arrest (CA) cohort estimates the annual incidence of SCD as more than 41 per 100,000 persons (annually 20,000 persons experienced the out-of-hospital CA in 2006/2007), which is similar to other countries such USA, Canada, Ireland, Japan, and China. The EMS (emergency medical services) is not ready for CA victims. The Collapse-to-Call time is about 5 minutes. And the bystander CPR (cardiopulmonary resuscitation) rate was 1.4%. An AED (automatic external defibrillation) was used by less than 10% of 119 EMT s. The survival discharge rate was 2.4%, and only 0.66% of the survivors were discharged with the acceptable neurological deficits (cerebral performance category [CPC] 1-2). Therefore we should increase bystander CPR and improve the EMS to get more SCD survivors. Also, lifestyle modification needs to be emphasized to prevent SCD. Key words: sudden cardiac death out-of-hospital cardiac arres annual incidence bystander CPR EMS clinical outcome Correspondence: Dong-Jin Oh, MD, PhD. Division of Cardiology, Department of Internal Medicine, KangDong Sacred Heart Hospital, Hallym University, 445 Gil-Dong, Kangdong-Gu, Seoul , Korea Tel: , Fax: ohdjarc@hallym.or.kr VOL.11 NO.2 13

14 MAIN TOPIC REVIEWS Table 1. The estimated annual incidence of sudden cardiac death (per 100,000 persons) USA 53 (41~89) Netherland 90~100 Japan (Okinawa) 39 China 41 West Ireland 51 Canada 56 Korea more than 41 (up to 80) Table 2. The clinical outcome of out-of-hospital cardiac arrest (SCD) (percent) Nation Survival CPC 1~2 Korea Sweden 14.0 Japan ( 06) Osaka 12 6 USA ( 06~ 07) ROC 8.4 ( 05~ 08) CARES SCD; sudden cardiac death, CPC; cerebral performance category 14 Journal of Cardiac Arrhythmia

15 MAIN TOPIC REVIEWS Table 3. CPC Scale Note: If patient is anesthetized, paralyzed, or intubated, use as is clinical condition to calculate scores. CPC 1. Good cerebral performance: conscious, alert, able to work, might have mild neurologic or psychologic deficit. CPC 2. Moderate cerebral disability: conscious, sufficient cerebral function for independent activities of daily life. Able to work in sheltered environment. CPC 3. Severe cerebral disability: conscious, dependent on others for daily support because of impaired brain function. Ranges from ambulatory state to severe dementia or paralysis. CPC 4. Coma or vegetative state: any degree of coma without the presence of all brain death criteria. Unawareness, even if appears awake (vegetative state) without interaction with environment; may have spontaneous eye opening and sleep/awake cycles. Cerebral unresponsiveness. CPC 5. Brain death: apnea, areflexia, EEG silence, etc. (from Safar P. Resuscitation after Brain Ischemia, in Grenvik A and Safar P Eds: Brain Failure and Resuscitation, Churchill Livingstone, New York, 1981; ) VOL.11 NO.2 15

16 MAIN TOPIC REVIEWS References 1. Korean Statistical Information Service. Causes of Death in Korean. Statistics Korea 2007 & SD Shin. The Report of Cardiac Arrest Cohort. Ministry of Health and Welfare. Korean Center for Disease Control and Prevention, Chugh SS, Reinier K, Teodorescu C, Evanado A, Kehr E, Al Samara M, Mariani R, Gunson K, Jui J. Epidemiology of Sudden Cardiac Death: Clinical and Research Implications. Prog Cardiovasc Dis. 2008;51: Zhang S. Sudden Cardiac Death in China. Pacing Clin Electrophysiol. 2009;32: KJ Song, DJ Oh. Current Status of CPR in Korea. Korean J Med. 2007;73: Myerburg RJ, Kessler KM, Castellanos A. Sudden cardiac death. Structure, function, and time-dependence of risk. Circulation. 1992;85(1 supple):i2-i Safar P. Resuscitation after Brain Ischemia, in Grenvik A and Safar P Eds: Brain Failure and Resuscitation, Churchill Livingstone, New York, 1981; Journal of Cardiac Arrhythmia

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19 MAIN TOPIC REVIEWS day 1 day 2 day 4 Figure 1. Dynamic change of ST segment in Brugada syndrome. Table 1. ST segment abnormalities in V1 to V3 Type 1 Type 2 Type 3 J wave amplitude 2 mm 2 mm 2 mm T wave negative positive or biphasic positive ST-T configuration coved type saddleback saddleback V1 V1 V1 V2 V2 V2 ST segment (terminal portion) 1 mm 1 mm 1 mm=0.1 mv. The terminal portion of the ST segment refers to the latter half of the ST segment. VOL.11 NO.2 19

20 MAIN TOPIC REVIEWS Table 2. Diagnostic criteria for long QT syndrome (LQTS) Electrocardiographic findings Corrected QT interval, seconds (in male) Torsades de pointes T wave alternans Notched T wave in 3 leads Low heart rate for age Clinical history Syncope With stress Without stress Congenital deafness Family history Family members with definitive LQTS Unexplained sudden cardiac death at <30 Years among immediate family member (s) Points Scoring : 1 point, low probability of LQTS ; 2 to 3 points, intermediate probability of LQTS; and 4 points, high probability of LQTS. (From Schwartz PJ, et al. Circulation. 1993;88: ) Journal of Cardiac Arrhythmia

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22 MAIN TOPIC REVIEWS References 1. Naccarelli GV, Antzelevitch C. The Brugada syndrome: clinical, genetic, cellular, and molecular abnormalities. Am J Med. 2001;110: Vatta M, Li H, Towbin JA. Molecular biology of arrhythmic syndromes. Curr Opin Cardiol. 2000;15: Nacarelli GV, Antzelevitch C, Wolbrette DL, Luck JC. The Brugada syndrome. Curr Opin Cardiol. 2002;17: Clancy CE, Rudy Y. Na+ channel mutation that causes both Brugada and long-qt syndrome phenotypes: a simulation study of mechanism. Circulation. 2002;105: Weiss R, Barmada MM, Nguyen T, Seibel JS, Cavlovich D, Kornblit CA, Angelilli A, Villanueva F, McNamara DM, London B. Clinical and Molecular heterogeneity in the Brugada syndrome: a novel gene locus on chromosome 3. Circulation. 2002;105: Yan G-X, Antzelevitch C. Cellular basis for the Brugada syndrome and other mechanisms of arrhythmogenesis associated with ST-segment elevation. Circulation. 1999;100: Gussak I, Antzelevitch C, Bjerregaard P, Towbin JA,Chitman BR. The Brugada syndrome: clinical, electrophysiologic and genetic aspects. J Am Coll Cardiol. 1999;33: Wichter T, Matheja PM, Eckardt L, Kies P, Schäfers K, Schulze-Bahr E, Haverkamp W, Borggrefe M, Schober O. Breithardt G, Schafers M. Cardiac autonomic dysfunction in Brugada syndrome. Circulation. 2002;105: Brugada R, Brugada J, Antzelevitch C, Kirsch GE, Potenza D, Towbin JA, Brugada P. Sodium channel blockers identify risk for sudden death in patients with ST-segment elevation and right bundle branch block but structurally normal hearts. Circulation. 2000;101: Antzelevitch C. Ion channels and ventricular arrhythmias: Cellular and ionic mechanisms underlying the Brugada syndrome. Curr Opin Cardiol. 1999;14: Priori SG, Napolitano C, Gasparini M, Pappone C, Bella PD, Brignole M, Giordano U, Giovannini T, Menozzi C, Bloise R, Crotti L, Terreni L, Schwartz PJ. Clinical and genetic heterogeneity of right bundle branch block and ST-segment elevation syndrome: a prospective evaluation of 52 families. Circulation. 2000;102: Antzelevitch C, Brugada P, Borggrefe M, Brugada J, Brugada R, Corrado 22 Journal of Cardiac Arrhythmia

23 D, Gussak I, LeMarec H, Nademanee K, Riera ARP, Shimizu W, Schulze- Bahr E, Tan H, Wilde A. Brugada syndrome. Report of the second consensus conference. Circulation. 2005;111: H, Sakabe K, Sakata T, Takami M, Tezuka N, Noro M, Enjoji Y, Tejima T, Sugi K, Yamaguchi T. Assessment of noninvasive markers in identifying patients at risk in the Brugada syndrome: insight into risk stratification. J Am Coll Cardiol. 2001;37: Atarashi H, Ogawa S, Harumi K, Sugimoto T, Inoue H, Murayama M, Toyama J, Hayakawa H for the idiopathic ventricular fibrillation investigators. Three-year follow-up of patients with right bundle branch block and ST segment elevation in the right precordial leads. J Am Coll Cardiol. 2001;37: Brugada J, Brugada R, Antzelevitch C, Towbin J, Nadermanee K, Brugada P. Long-term follow-up of individuals with the electrocardiographic pattern of right bundle-branch block and ST-segment elevation in precordial leads V 1 to V 3. Circulation. 2002;105: Eckdart L, Probst V, Smits JPP, Bahr ES, Wolpert C, Schimpf R, Wichter T, Boisseau P, Heinecke A, Breithardt G, Borggrefe M, Lemarec H, Böcker D, Wilde AAM. Long-term prognosis of individuals with right precordial STsegment-elevation Brugada syndrome. Circulation. 2005;111: Priori SG, Napolitano C, Gasparini M, Pappone C, Bella PD, Bella PD, Giordano U, Bloise R, Giustetto C, Nardis RD, Grillo M, Ronchetti E, Faggiano G, Nastoli J. Natural history of Brugada syndrome: Insights for risk stratification and management. Circulation. 2002;105: Wehrens XHT, Vos MA, Doevendans PA, Wellens HJJ. Novel insights in the congenital long QT syndrome. Ann Intern Med. 2002:137: Wever EFD, Robles de Medina EO. Sudden death in patients without structural heart disease. J Am Coll Cardiol. 2004;43: MAIN TOPIC REVIEWS VOL.11 NO.2 23

24 MAIN TOPIC REVIEWS Drugs and supplements related to sudden cardiac death ABSTRACT A wide range of drugs and supplements can cause QT prolongation which could increase the risk of torsade de pointes (TdP) and sudden cardiac death (SCD). Most of the drugs that prolong the QT interval lengthen the cardiac repolarization period mostly by blocking specific cardiac K + channel (I Kr ). Triggered beats from early afterdepolarization in the prolonged QT interval may initiate TdP. Transmural dispersion or variability of repolarization caused by drugs could be associated with increased risk of TdP. Bradycardia, electrolyte imbalance, female gender and genetic polymorphism could also play a role in increasing the risk of druginduced TdP. Some weight-loss supplements and herbal supplements are known to have life-threatening adverse cardiac effects. These supplements contain several ingredients, i.e. Ma huang, Citrus aurantium, licorice and guarana, which could result QT prolongation, ventricular fibrillation and SCD. In brief, it is important to reduce the risk of SCD by avoiding drugs or supplements which could prolong the QT interval and correct predisposing factors for drug-induced TdP. Key words: sudden cardiac death long QT syndrome torsade de pointes Correspondence: Eue-Keun Choi, MD, PhD, Division of Cardiology, Department of Internal Medicine, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul , Korea Tel: , Fax: choiek17@snu.ac.kr 24 Journal of Cardiac Arrhythmia

25 MAIN TOPIC REVIEWS Table 1. Drugs with QT interval-prolonging potential Antiarrhythmic drugs IA III IV Procainamide, Quinidine*, Disopyramide* Amiodarone, Sotalol, Dofetilide*, Ibutilide* Verapamil Nonantiarrhythmic drugs Antidepressants Amitriptyline, Doxepin, Fluoxetine, Imipramine, Trazodone, Venlafaxine, Desipramine*, Maprotiline* Antipsychotics Amisulpride, Chlorpromazine, Clozapine, Haloperidol, Mesoridazine, Olanzapine, Pimozide, Prochlorperazine, Risperidone, Droperidol Antiemetics Dolasetron, Granisetron Antibiotics Clarithromycin Erythromycin Pentamidine Spafloxacin* Grepafloxacin Antifungals Fluconazole Ketoconazole Antihistamines Azelastine, Clemastine, Diphenhydramine, Fexofenadine, Astemizole, Terfenadine Antiasthmatics Fenoterol, Procaterol, Salbutamol, Salmeterol Diuretics Indapamide, Triamterene Gastrointestinal Domperidone, Cisapride prokinetics Immunosuppressants Tacrolimus Anesthetics Enflurane, Fentanyl, Isoflurane, Ketamine, Penobarbital, Propofol, Thiopental Black bold, available in Korea; *not available in Korea; withdrawn from market (modified from Morissette, et al. Can J Cardiol. 2005;21: ) VOL.11 NO.2 25

26 MAIN TOPIC REVIEWS References 1. Roden DM, Viswanathan PC. Genetics of acquired long QT syndrome. J Clin Invest. 2005;115: Kannankeril PJ, Roden DM. Drug-induced long QT and torsade de 26 Journal of Cardiac Arrhythmia

27 pointes: recent advances. Curr Opin Cardiol. 2007;22: Antzelevitch C. Role of transmural dispersion of repolarization in the genesis of drug-induced torsades de pointes. Heart Rhythm. 2005;2(2 Suppl):S Shimizu W, Ohe T, Kurita T, Kawade M, Arakaki Y, Aihara N, Kamakura S, Kamiya T, Shimomura K. Effects of verapamil and propranolol on early afterdepolarizations and ventricular arrhythmias induced by epinephrine in congenital long QT syndrome. J Am Coll Cardiol. 1995;26: Nazeri A, Massumi A, Wilson JM, Frank CM, Bensler M, Cheng J, Saeed M, Rasekh A, Razavi M. Arrhythmogenicity of weight-loss supplements marketed on the Internet. Heart Rhythm. 2009;6: Benitez D, Gaydecki PA, Zaidi A, Fitzpatrick AP. The use of the Hilbert transform in ECG signal analysis. Comput.Biol.Med. 2001;31: Theoharides TC. Sudden death of a healthy college student related to ephedrine toxicity from a ma huang-containing drink. J Clin Psychopharmacol. 1997;17: Bryer-Ash M, Zehnder J, Angelchik P, Maisel A. Torsades de pointes precipitated by a Chinese herbal remedy. Am J Cardiol. 1987;60: Eriksson JW, Carlberg B, Hillorn V. Life-threatening ventricular tachycardia due to liquorice-induced hypokalaemia. J Intern Med. 1999;245: Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med. 2000;343: Caron MF, Hotsko AL, Robertson S, Mandybur L, Kluger J, White CM. Electrocardiographic and hemodynamic effects of Panax ginseng. Ann Pharmacother. 2002;36: Database. NMC Kim WS LS, Kang HS, Choue CW, Kim KS, Song JS, Bae JH. Cardiovascular aspects of aconitine poisoning. Korean Circ J. 2000;30: Gunduz A, Turedi S, Uzun H, Topbas M. Mad honey poisoning. Am J Emerg Med. 2006;24: MAIN TOPIC REVIEWS VOL.11 NO.2 27

28 MAIN TOPIC REVIEWS Stress, heart disease and cardiac arrhythmias ABSTRACT The association of acute mental stress with myocardial infarction or fatal cardiac arrhythmias has been well demonstrated in epidemiologic studies conducted during natural disasters, terrorism or wars. The underlying pathophysiologic process includes acute increase in arterial blood pressure, endothelial dysfunction, aggravation of myocardial ischemia, coagulation abnormalities and hemoconcentration initiated by activation of the sympathetic nervous system and hypothalamic-pituitary-adrenal gland axis. In addition, psychococial factors related to life-style or work, type of personality, and environmental factors such as exposure to noise or traffic have also been identified as potential triggers of acute myocardial infarction. This article briefly summarizes the epidemiology and the pathophysiologic mechanism of acute or long-term mental stress on cardiac diseases and arrhythmias. Key words: stress arrhythmia myocardial infarction Correspondence: Gi-Byoung Nam, MD, Division of Cardiology, Department of Internal Medicine, University of Ulsan College of Medicine, Poongnap-dong, Songpa-gu, Seoul , Korea Tel: , Fax: Journal of Cardiac Arrhythmia

29 MAIN TOPIC REVIEWS VOL.11 NO.2 29

30 MAIN TOPIC REVIEWS References 1. Hjalmarson A. Effects of beta blockade on sudden cardiac death during acute myocardial infarction and the postinfarction period. Am J Cardiol. 1997;80(9B):35J-39J. 2. Carson PA, O'Connor CM, Miller AB, Anderson S, Belkin R, Neuberg GW, Wertheimer JH, Frid D, Cropp A, Packer M. Circadian rhythm and sudden death in heart failure: results from Prospective Randomized Amlodipine Survival Trial. J Am Coll Cardiol. 2000;36: Rosengren A, Hawken S, Ounpuu S, Sliwa K, Zubaid M, Almahmeed WA, Blackett KN, Sitthi-amorn C, Sato H, Yusuf S; INTERHEART investigators. Association of psychosocial risk factors with risk of acute myocardial infarction in cases and controls from 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364: Journal of Cardiac Arrhythmia

31 MAIN TOPIC REVIEWS Therapeutic hypothermia after cardiac arrest ABSTRACT Brain injury is the leading cause of death in a patient resuscitated from cardiac arrest. Therapeutic hypothermia (TH), which maintains the body temperature approximately 32 to 34 during the first 12 to 24 hours after resuscitation, improves the neurologic outcome after cardiac arrest. The 2005 International Liaison Committee on Resuscitation recommends the use of TH for comatose patients following successful resuscitation from cardiac arrest. TH can be accomplished by either external cooling devices or intravascular cooling methods, or both. External cooling devices include temperature regulating apparatus with cooling blankets or water circulating cold pads. Various endovascular cooling devices are in use for intravascular cooling. A rapid infusion of a large amount of iced saline will facilitate to reach the target body temperature for TH. Complications associated with hypothermia, which include infection, coagulopathy, or cardiac arrhythmias, are not frequently observed during TH after cardiac arrest. Key words: therapeutic hypothermia cardiac arrest cardiopulmonary resuscitation Correspondence: Sung-Oh Hwang, MD, Department of Emergency Medicine, Wonju College of Medicine, Yonsei University, 162 Ilsan-dong, Wonju , Korea Tel: , Fax: shwang@yonsei.ac.kr VOL.11 NO.2 31

32 MAIN TOPIC REVIEWS 32 Journal of Cardiac Arrhythmia

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34 MAIN TOPIC REVIEWS References 1. Nadkarni VM, Larkin GL, Peberdy MA, Carey SM, Kaye W, Mancini ME, Nichol G, Lane-Truitt T, Potts J, Ornato JP, Berg RA; National Registry of Cardiopulmonary Resuscitation Investigators. First documented rhythm and clinical outcome from in-hospital cardiac arrest among children and adults. JAMA. 2006;295: Neumar RW, Nolan JP, Adrie C, Aibiki M, Berg RA, Bottiger BW, Callaway C, Clark RS, Geocadin RG, Jauch EC, Kern KB, Laurent I, Longstreth WT Jr, Merchant RM, Morley P, Morrison LJ, Nadkarni V, Peberdy MA, Rivers EP, Rodriguez-Nunez A, Sellke FW, Spaulding C, Sunde K, Vanden Hoek T. Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A consensus statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation. 2008;118: Taraszewska A, Zelman IB, Ogonowska W, Chrzanowska H. The pattern of irreversible brain changes after cardiac arrest in humans. Folia Neuropathol. 2002;40: Ames A III, Wright RL, Kowada M, Thurston JM, Majno G. Cerebral ischemia, II: the no-reflow phenomenon. Am J Pathol. 1968;52: Wolfson SK Jr, Safar P, Reich H, Clark JM, Gur D, Stezoski W, Cook EE, Krupper MA. Dynamic heterogeneity of cerebral hypoperfusion after prolonged cardiac arrest in dogs measured by the stable xenon/ct technique: a preliminary study. Resuscitation. 1992;23: Boels PJ, Verbeuren TJ, Vanhoutte PM. Moderate cooling depresses the accumulation and the release of newly synthesized catecholamines in isolated canine saphenous veins. Experientia. 1985;41: Okuda C, Saito A, Miyazaki M, Kuriyama K. Alteration of the turnover of dopamine and 5-hydroxytryptamine in rat brain associated with hypothermia. Pharmacol. Biochem. Behav. 1986;24: Karibe H, Zarow GJ, Graham SH, Weinstein PR. Mild intraischemic hypothermia reduces postischemic hyperperfusion, delayed postischemic hypoperfusion, blood-brain barrier disruption, brain edema, and neuronal damage volume after temporary focal cerebral ischemia in rats. J Cereb Blood Flow Metab. 1994;14: Takasu A, Yagi K, Okada Y. Effect of mild hypothermia on ischemia induced release of endothelin-1 in dog brain. Resuscitation. 1996;31: Marion DW, Penrod LE, Kelsey SF, Obrist WD, Kochanek PM, Palmer AM. Treatment of traumatic brain injury with moderate hypothermia. N Engl J Med. 1997;336: Hypothermia after Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med. 2002;346: Bernard SA, Gray TW, Buist MD, Jones BM, Silvester W, Gutteridge G, et al. Treatment of comatose survivors of out-ofhospital cardiac arrest with induced hypothermia. N Engl J Med. 2002;346: International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Circulation. 2005; 112(suppl):IV-19-IV Colbourne F, Sutherland GR, Auer RN. Electron microscopic evidence against apoptosis as the mechanism of neuronal death in global ischemia. J Neurosci. 1999;19: Arrich J. European Resuscitation Council Hypothermia After Cardiac Arrest Registry Study Group. Clinical application of mild therapeutic hypothermia after cardiac arrest. Crit Care Med. 2007;35: Haugk M, Sterz F, Grassberger M, Uray T, Kliegel A, Janata A, Richling N, Herkner H, Laggner AN. Feasibility and efficacy of a new non-invasive surface cooling device in post-resuscitation intensive care medicine. Resuscitation. 2007;75: Merchant RM, Abella BS, Peberdy MA, Soar J, Ong ME, Schmidt GA, Becker LB, Vanden Hoek TL. Therapeutic hypothermia after cardiac arrest: unintentional overcooling is common using ice packs and conventional cooling blankets. Crit Care Med. 2006;34(12 suppl):s490-s Bernard S, Buist M, Monteiro O, Smith K. Induced hypothermia using large volume, ice-cold intravenous fluid in comatose survivors of out-of-hospital cardiac arrest: a preliminary report. Resuscitation. 2003;56: Al-Senani FM, Graffagnino C, Grotta JC, Saiki R, Wood D, Chung W, Palmer G, Collins KA. A prospective, multicenter pilot study to evaluate the feasibility and safety of using the CoolGard System and Icy catheter following cardiac arrest. Resuscitation. 2004;62: Diringer MN, Neurocritical Care Fever Reduction Trial Group. Treatment of fever in the neurologic intensive care unit with a catheter-based heat exchange system. Crit Care Med. 2004;32: Hoedemaekers CW, Ezzahti M, Gerritsen A, van der Hoeven JG. Comparison of cooling methods to induce and maintain normoand hypothermia in intensive care unit patients: a prospective intervention study. Crit Care. 2007;11:R Polderman KH. Application of therapeutic hypothermia in the intensive care unit: opportunities and pitfalls of a promising treatment modality, part 2: practical aspects and side effects. Intensive Care Med. 2004;30: Wadhwa A, Sengupta P, Durrani J, Akca O, Lenhardt R, Sessler DI, Doufas AG. Magnesium sulphate only slightly reduces the shivering threshold in humans. Br J Anaesth. 2005;94: Arrich J, Holzer M, Herkner H, Mullner M. Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation. Cochrane Database Syst Rev. 2009;7:CD Journal of Cardiac Arrhythmia

35 Heart Rhythm 2010 CONFERENCE COVERAGE Science. Discovery. Innovation. Leader s in quality Leading experts collaborating to share today s innovations and meet tomorrow s challenges 31th ANNUAL SCIENTIFIC SESSIONS MAY 12-15, 2010 DENVER, CO Correspondence: Nam-Ho Kim, MD, Division of Cardiology, Department of Internal Medicine, Wonkwang University Medical School, Shinyongdong, Iksan, Jeonbuk , Korea Tel: , Fax: cardionh@wonkwang.ac.kr Douglas L. Packer VOL.11 NO.2 35

36 CONFERENCE COVERAGE 36 Journal of Cardiac Arrhythmia

37 < < CONFERENCE COVERAGE VOL.11 NO.2 37

38 ECG & EP CASES A case of brugada syndrome presented as chest pain ABSTRACT Brugada syndrome was described in 1992 as a new clinical entity characterized by electrocardiographic STsegment elevation in the right precordial leads (V1~V3) and the occurrence of sudden cardiac death (SCD) during its clinical course. Brugada syndrome is known to be linked with the mutations of SCN5A, the gene encoding subunit of the cardiac sodium channel. Furthermore, these abnormal cardiac sodium channels were found to show variable degrees of dysfunctioning in relation to changes in body temperature and electrocardiogram(ecg) findings of Brugada syndrome sometimes happen to reveal with the presence of high fever. We experienced a 44-year-old man with Brugada syndrome in whom the diagnosis of acute coronary syndrome had been mistakenly made because of an initial clinical presentation with complains of severe chest pain and accompanying ST segment elevations. The ST segment elevations in leads I and avl, which extended the right precordial leads, led the physician to suspect transient pericarditis caused by coexisting pneumonia. In this case, a diagnosis of idiopathic Brugada syndrome was reconfirmed by a flecainide challenge test. Key words: brugada syndrome ECG fever chest pain 38 Journal of Cardiac Arrhythmia

39 < < ECG & EP CASES VOL.11 NO.2 39

40 ECG & EP CASES 내원하여, 시행한 심전도상 ST분절의 상승이 V1~V4 유도 열과 동반되어 브루가다 type 1에 해당되는 심전도 소견이 에서 관찰되었으며, 유도 I, avl에서도 ST 상승이 의심되 저명하게 관찰되었고, 폐렴 치료 후 체온의 정상화와 동반 어 진단에 혼선을 빚었던 경우이다. 전산화 단층촬영 소견 되어 심전도 소견 또한 정상화되었던 경우이다. 과 경과 중 발생한 38.5 고열의 발생을 통하여 늑막염이 퇴원 전 flecainide 유발 검사를 시행하여 브루가다 type 동반된 폐렴으로 흉통의 원인진단이 이루어졌으며, 특히 고 1형태의 심전도 변화를 재확인하고 심전기생리 검사를 시 A B C Figure 1. The twelve-lead ECG on admission: marked ST segment elevations were noted on the right precordial leads (V1-V4) and subtle ST segment elevations also noted in lead 1 and avl (A), with a fever of 38.5 on HD 2: Brugada Type 1 ECG pattern (B), and with normal temperature on HD 7: normal ECG with resolved ST-segment elevation (C). 40 Journal of Cardiac Arrhythmia

41 ECG & EP CASES A B Figure 2. Chest CT scan on admission showed pulmonary infiltration of the right middle lobe lateral segment, and pulmonary infiltration of the right lower lobe anterobasal segment with pleural involvement. A B Figure 3. On flecainide provocation test, the baseline electrocardiaram(ecg) showed normal (A), and after 5 minutes, the ECG showed the Brugada Type 1 ECG pattern (B). V5, V6 leads were placed 1 intercoastal space above leads V1 and V2 respectively. VOL.11 NO.2 41

42 ECG & EP CASES References 1. Brugada P, Brugada J. Right bundle branch block, persistent ST segment and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report. J Am Coll Cardiol. 1992;20: Chen Q, Kirsch GE, Zhang D, Brugada R, Brugada J, Brugada P, Potenza D, Moya A, Borggrefe M, Breithardt G, Oritz-Lopez R, Wang Z. Genetic basis and molecular mechanisms for idiopathic ventricular fibrillation. Nature. 1998;392: Dumaine R, Towbin JA, Brugada P, Vatta M, Nesterenko DV, Nesterenko VV, Brugada J, Brugada P, Antzelevitch C. Ionic mechanisms responsible for the electrocardiographic phenotype of the Brugada syndrome are temperature dependent. Circ Res. 1999;85: Antzelevitch C. The Brugada syndrome: ionic basis and arrhythmia mechanisms. J Cardiovasc Electrophysiol. 2001;12: Journal of Cardiac Arrhythmia

43 ECG & EP CASES A case of ischemic non-sustained ventricular tachycardia treated by ICD for primary prevention of sudden cardiac death ABSTRACT It has been reported that 75% of the patients dying of sudden cardiac death (SCD) have coronary heart disease. The rhythm most often recorded at the time of sudden cardiac arrest is ventricular fibrillation. No antiarrhythmic agent has clearly been demonstrated to reduce total and SCD mortality in patients at risk for SCD. Implantable cardioverter-defibrillator (ICD) therapy, compared with conventional or traditional antiarrhythmic drug therapy, has been associated with mortality reductions from 23% to 55%, depending on the risk group participating in the trial. The improvement in survival with ICD therapy is almost exclusively due to a reduction in SCD. We reported here on a syncope patient with a history of previous myocardial infarction. The cardiac electrophysiology study revealed sustained ventricular tachycardia and fibrillation presented with loss of consciousness. Key words: sudden cardiac death coronary heart disease implantable cardioverter-defibrillator Correspondance: Young-Keun On, MD, Division of Cardiology, Department of Medicine Cardiac & Vascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul , Korea Tel: , Fax: yk.on@samsung.com VOL.11 NO.2 43

44 ECG & EP CASES Figure 1. Surface electrocardiogram showed normal sinus rhythm and QRS morphology revealed QS in precordial lead V3, V4, and V5. Figure 2. Nonsustained VT was noted in 24 hr Holter monitoring. 44 Journal of Cardiac Arrhythmia

45 계획자극 V1/V2/V3/V4 (500 msec/280 msec/270 msec/260 견을 보였다. msec)에 의하여 유발되었고, 빈맥의 모양은 RBBB with 두근거림 소견으로 시행한 24시간 홀터 검사에서 6 right axis deviation, 맥박수는 분당 293회였으며(Figure beats의 비지속성 심실빈맥 소견이 관찰되었다. 다시 검사 3, 4), 환자는 의식을 잃었고 제세동기에 의하여 정상 동율 한 관동맥조영술에는 과거 관동맥성형술 시행 부위의 협착 동 회복 후 의식을 회복하였다. 및 혈전 등의 이상 소견은 관찰되지 않았다(Figure 2). ECG & EP CASES 으며, 좌심실 수축 기능은 좌심실 박출률 33%로 감소된 소 환자는 10년 전 급성심근경색으로 관동맥성형술을 시행 빈맥의 원인을 찾기 위하여 심전기생리 검사를 시행하였 하였고, 심초음파상 좌심실 박출률 33%, 홀터 검사 상 비지 고, 전극도자를 통한 계획자극에 의하여 지속성 심실빈맥이 속성 심실빈맥 소견, 심전기생리 검사 결과 허혈성 심질환 반복적으로 유발되었다. 지속성 심실빈맥이 우심실 심첨부 에 의한 심실빈맥 소견으로 향후의 돌연 심장사의 예방 목 Figure 3. Sustained VT was induced with V1/V2/V3/V4 (500 msec/280 msec/270 msec/260 msec). The heart rate of tachycardia was 293 bpm and RBBB pattern with right axis deviation. The patient lost his consciousness during the tachycardia. Figure 4. Surface electrocardiogram during the ventricular tachycardia. VOL.11 NO.2 45

46 ECG & EP CASES References 1. Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Myerburg RJ, Chaitman B, Fromer M, Gregoratos G, Moss AJ, Klein G, Priori SG, Miguel A. Quinones MA, Roden DM, Silka MJ, Tracy C. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death. J Am Coll Cardiol. 2006;48:e247-e Adabag AS, Therneau TM, Gersh BJ, Weston SA, Roger VL. Sudden death after myocardial infarction. JAMA. 2008;300: Steinbeck G, Andresen D, Seidl K, Brachmann J, Hoffmann E, Wojciechowski D, Kornacewicz-Jach Z, Sredniawa B, Lupkovics G, Hofgartner F, Lubinski A, Rosenqvist M, Habets A, Wegscheider K, Senges J; IRIS InvestigatorsDefibrillator implantation early after myocardial infarction. N Engl J Med. 2009;361: Journal of Cardiac Arrhythmia

47 ECG & EP CASES A case of nonischemic dilated cardiomyopathy with ventricular tachycardia treated by ICD ABSTRACT Dilated cardiomyopathy (DCM) is a syndrome characterized by left or biventricular dilatation and impaired systolic function. ICD (implantable cardioverter defibrillator) is superior to anti-arrhythmic drugs in secondary prevention of overall death and SCD in the general HF population. Similar results were also shown in primary prevention in ischemic DCM. We experienced 50 years old man presented as non-ischemic dilated cardiomyopathy with ventricular tachycardia. ICD was inserted as secondary prevention. But in spite of ICD insertion, patient has developed aggravation of heart failure during 2 years of follow up. Key words: nonischemic dilated cardiomyopathy EF (ejection fraction) ICD Correspondence: Dae-Kyeong Kim, MD, Division of Cardiology, Department of Internal Medicine, College of Medicine, The Inje University of Korea, , kaekeum-dong, Busanjin-Gu , Busan, Korea Tel: , Fax: epkimdk@yahoo.co.kr VOL.11 NO.2 47

48 ECG & EP CASES Figure 1. Electrocardiogram from a local clinic shows a wide QRS tachycardia cardioverted to NSR after shock. 48 Journal of Cardiac Arrhythmia

49 차이가 없다고 보고한 바 있다. 그렇지만 심실 구혈률에 의 의하여, III, IV 환자들은 심부전의 악화에 의한 경우가 많 한 예측치가 가장 높다는데 이의가 없는 것 같다. 1990년대 1 다고 한다. QT dispersion, T wave alternance, heart 이후 ACE 억제제와 베타차단제의 사용으로 생존율이 향상 rate variations, signal average EKG, 전기생리학 검사 등 되었는데, 이는 수축기 기능의 회복이 중요한 역할을 한다 급사의 위험 정도를 평가하는 여러 연구가 시도되었으나, 는 반증이 된다. 폐동맥압의 상승은 LV filling pressure의 연구결과마다 차이가 있고 그 유용성에 대해서도 의견이 다 backward transmission과 혈관저항 증가로 설명될 수 있 2 양하다. Grimm 등 은 NICM 환자에서는 전기생리학 검사 다. 전통적으로 폐모세혈관 쐐기압(pulmonary capillary 에서 부정맥이 유발되어도 유발되지 않은 군과 급사 발생은 wedge pressure, PCWP)가 예후를 반영하는 주요한 혈역 A ECG & EP CASES 며, NYHA functional class I, II의 환자는 주로 부정맥에 B Figure 2. The coronary angiogram does not show any significant lesion. Figure 3. Ventricular tachycardia (RBRS) inducted at a cycle length of 500/24/210/230. VOL.11 NO.2 49

50 ECG & EP CASES A B Figure 4. The change of mitral inflow from pseudonormal (A) to restrictive pattern (B). < < < References 1. Sugrue DD, Rodeheffler RJ, Codd MB, Billard DJ, Fuster V, Gersh BJ. The clinical course of idiopathic cardiomyopathy: a population-based study., Ann Intern Med. 1992;117: Grimm W, Hoffmann J, Menz V, Luck K, Maisch B. Programmed venticular stimulation for arrhythmia risk prediction in patients with idiopathic dilated cardiomyopathy and nonsustained ventricular tachycardia. J Am Coll Cardiol. 1998;32: Ghio S. Pulmonary hypertension in advanced heart failure. Herz. 2005;30: Gavazzi A, Ghio S, Scelsi L, Campana C, Klersy C, Serio A, Raineri C, Tavazzi L. Response of the right ventricle to acute pulmonary vasodilation predicts the outcome in patients with advanced heart failure and pulmonary hypertension. Am Heart J. 2003;145: Strickberger SA, Hummel JD, Bartlett TG, Frumin HI, Schuger SL, Bitar C, Morady F; AMIOVIRT Investigatora. Amiodarone versus implantable cardioverter-defibrillator: randomized trial in patients with nonischemic dilated cardiomyopathy and asymptomatic nonsustained ventricular tachycardia-amiovert. J Am Coll Cardiol. 2003;41: Bansch D, Antz M, Boczor S Volkmer M, Tebbenjohanns J, Seidl K, Block M, Geitzen F, Berger J, Kuck KH. Primary prevention of 50 Journal of Cardiac Arrhythmia

51 sudden cardiac death in idiopathic dilated cardiomyopathy: the Cardiomyopathy Trial (CAT). Circulation. 2002;105: Kadish A, Dyer A, Daubert JP, Quigg R, Estes NA, Anderson KP, Calkins H, Hoch D, Goldberger J, Shalaby A, Sanders WE, Schaechter A, Levine JH; Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Investigators. Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. N Engl J Med. 2004;350: Bardy GH, Lee KL, Mark DB, Poole JE, Packer DL, Boineau R, Domanski M, Troutman C, Anderson J, Johnson G, McNulty SE, Clapp-Channing N, Davidson-Ray LD, Fraulo ES, Fishbein DP, Luceri RM, Ip JH; Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) Investigators. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med. 2005;352: ECG & EP CASES VOL.11 NO.2 51

52 ECG & EP CASES A case of atrioventricular dissociation with interference ABSTRACT Interference dissociation is one of the most interesting arrhythmias. Once thought to be a rare arrhythmia, it is now considered a very common one. A 69-year-old female patient presented to our hospital with a chief complaint of dizziness and dyspnea on exertion that worsened since a month ago. On electrocardiogram, marked bradycardia (VR [ventricular rhythm] = 42 beat/min) was noted. P waves, without QRS correlation were seen, and the QRS complex was narrow. As the same rhythm was detected on 24-hour Holter monitoring with the patient experiencing dizziness, stress testing was performed upon which chronotropic incompetence was found. During an electrophysiology study, the abnormal finding of sinus node recovery time (RAP 500 ms) of 4,964 ms was noted. Therefore, a pacemaker of AAI type was inserted. Interference dissociation is defined as one of the dissociations caused by repetitive contradirectional interference, which leads to A-V dissociation. In general, as the ventricular rhythm is faster than the atrial rhythm, the P wave is seen progressively closer to the QRS complex, then disappears altogether, When passing through the QRS complex, to re-appear after the QRS complex. The P wave passing through the QRS complex is seen as ventricular capture, atrial capture, synchronization, or accrochage. Key words: interference dissociation ventricular capture chronotropic incompetence Correspondence: Jung-Hoon Sung, MD, PhD. Division of Cardiology, Department of Internal Medicine, CHA Bundang Medical Center, CHA University, 351 Yatap-dong, Bundang-gu, Seongnam-si, Gyeonggi-do , Korea Tel: , Fax: interspital@cha.ac.kr 52 Journal of Cardiac Arrhythmia

53 ECG & EP CASES A B P1 P2 P3 P4 P5 P6 P R1 R2 R3 R4 R5 R6 R7 Figure 1-A. The 12-lead electrocardiogram showes a sinus bradycardia allowing the escape of an AV junctional rhythm that does not capture the atria retrogradely. Intermittent sinus capture occurs (arrow) and produces incomplete AV dissociation. Figure 1-B. Interference dissociation between an S-A and A-V nodal rhythm is present. The rate of both the S-A and A- V nodal foci vary independently. In the first 2 cycles, the P-P interval lengthens progressively while the A-V nodal rate is fairly constant. As a result, P2 comes far enough beyond R2 to fall in the relative refractory phase of the bundle, and it is conducted to the ventricular after a P-R interval of 0.28 and an R-R interval of 0.64 second. VOL.11 NO.2 53

54 ECG & EP CASES Table 1. Secondary A-V Block, or interference (normal refractory period) I. Ipsedirectional interference A. delayed conduction B. dropped beats II. Contradirectional interference A. Isolated 1. direct 2. delayed B. repetitive (interference dissociation, A-V dissociation due to interference) 1. undirectional with block in opposite direction, which may be: a. primary, complete or incomplete b. secondary, due to ipsedirectional interference 2. bidirectional C. interference dissociation with capture 1. atrial 2. ventricular 3. both atrial and ventricular D. combinations of primary or secondary heart block with interference dissociation 1. block above level of A-V nodal pacemaker 2. block below level of A-V nodal pacemaker (from Circulation 1957;16: ) 54 Journal of Cardiac Arrhythmia

55 ECG & EP CASES Figure 2. Relationships of overdrive pacing into sinoatrial exit block. Atrial overdrive pacing at a cycle length of 500 msec demonstrates a long pause of approximately 4964 msec. Figure 3. Posteroanterior radiographic view of a AAI pacemaker in a patient. The atrial lead is in the right atrial appendage. VOL.11 NO.2 55

56 ECG & EP CASES References 1. MILLER R, SHARRETT RH. Interference dissociation. Circulation. 1957;16: PHILIP J. PODRID, PETTER R. KOWEY. CARDIAC ARRHYTHMIA: mechanisms, diagnosis, and management. 2 nd ed. 2001; Peter Libby, Robert O. Bonow, Douglas P. Zipes, Douglas L. Mann. Braunwald s Heart Disease: a textbook of cardiovascular medicine. 8 th ed. 2008; Journal of Cardiac Arrhythmia

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58 Smith HJ, Allen S, Yu W, Fard S. This is the title. Circulation. 2004;104:

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64 The Korean Society of Cardiac Arrhythmia Room 805, Masters Tower #553, Dohwa-dong, Mapo-gu, Seoul , Korea Phone Fax