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ORIGINAL ARTICLE Korean Circ J 2007;37:574-580 Print ISSN 1738-5520 / On-line ISSN 1738-5555 Copyright c 2007 The Korean Society of Cardiology 비후성심근증으로제세동기를삽입한환자의임상관찰 울산대학교의과대학서울아산병원내과학교실 김정욱 남기병 강병욱 홍윤기 장은영 김미영조재철 김형용 박경민 최기준 김유호 A Clinical Observation of Patients with Hypertrophic Cardiomyopathy and Implantable Cardioverter-Defibrillators Jong Wook Kim, MD, Gi-Byoung Nam, MD, Byung Wook Kang, MD, Yoonki Hong, MD, Eun Young Jang, MD, Mi-Young Kim, MD, Jae-Cheol Jo, MD, Hyoung Young Kim, MD, Kyoung-Min Park, MD, Kee-Joon Choi, MD and You-Ho Kim, MD Division of Cardiology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea ABSTRACT Background and Objectives: Hypertrophic cardiomyopathy (HCM) is one of the most common heritable cardiac diseases. Patients with HCM are prone to ventricular tachyarrhythmias, and implantable cardioverter-defibrillator (ICD) implantation is recommended in high-risk patients to prevent sudden death. Clinical and tachycardial characteristics in patients with HCM have not been studied systematically. Subjects and Methods: Between April 1996 and February 2006, 23 patients with HCM underwent implantation of ICDs. ICDs were indicated for primary prevention in 9 patients and for secondary prevention in 14 patients. Clinical features, follow-up events and intracardiac electrograms were reviewed. Results: During a median follow-up period of 561 days (range 16 to 2,694 days), a total of 51 episodes of ventricular tachycardia (VT) occurred in 6 patients, while only one episode of ventricular fibrillation (VF) was recorded. There were 45 (64.2%) appropriate shocks [30 defibrillation shocks in 5 patients and 15 antitachycardia pacings (ATP) in 2 patients] in 6 patients, and 25 (35.7%) inappropriate shocks in 7 patients. The coupling intervals and VT cycle lengths were highly variable within individual patients. Over-drive acceleration in response to ATP was observed in 1 patient. Conclusion: As ventricular tachycardia is the main ventricular tachyarrhythmia in patients with HCM, an empirical ATP setting for VTs appears to be mandatory even in patients without previously documented VT. Based on the analyses of the intracardiac electrograms (presence of overdrive acceleration, variations in coupling intervals and cycle lengths), triggered activity may have an important role in the mechanism of a ventricular tachycardia. (Korean Circ J 2007;37:574-580) KEY WORDS: Cardiomyopathy, hypertrophic;tachycardia, ventricular;defibrillators, implantable;death, sudden, cardiac. 서 론 비후성심근증은심근의비정상적인비후가나타나는유전성심장질환이며, 그유병률이인구약 500 명중한명으로 Received: June 2, 2007 Revision Received: July 18, 2007 Accepted: August 30, 2007 Correspondence: You-Ho Kim, MD, Division of Cardiology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736, Korea Tel: 82-2-3010-3161, Fax: 82-2-486-5918 E-mail: youho@amc.seoul.kr 비교적높은빈도로나타나고, 1) 젊은나이에급사를일으킬수있어임상적으로중요한질병으로알려져있다. 2) 비후성심근증으로급사에서소생되었거나향후급사의위험이높다고판단되는고위험군환자에서제세동기삽입은심실부정맥을효과적으로종료시킴으로써급사의위험을줄일수있는것으로알려져있다. 2-6) 고위험비후성심근증으로제세동기가삽입된환자들을대상으로하였던한다기관연구에서는평균 3년간의기간동안추적관찰한결과, 일차예방목적으로제세동기가삽입된경우연간 5%, 이차예방으로삽입된경우연간 11% 의비율로심실빈맥또는세동이 574

Jong Wook Kim, et al. 575 제세동기에의해종료되었다고보고하였다. 2) 하지만국내에서이러한비후성심근증의진단하에심장돌연사의일차혹은이차예방목적으로제세동기를삽입한환자에서심실성부정맥의발생률이나제세동기의쇼크치료의효율에대하여기술한연구는많지않다. 본연구에서는비후성심근증으로제세동기삽입술을시행받은환자들에서장기간추적관찰시나타나는심실성부정맥의치료효과를정리하고, 제세동기전기도기록을바탕으로심실성부정맥의전기생리학적특성을고찰하였다. 대상및방법 대상 1996 년 4월부터 2006 년 2월까지비후성심근증으로제세동기를삽입한환자 23명을대상으로평균 714±73 일 ( 범위 16~2,694 일 ) 동안이들의임상양상과추적관찰중심실빈 맥또는세동당시기록된심장내전기도를분석하였다. 적응증심장급사에서생존하였거나심실빈맥이증명된경우 ( 이차예방 ), 혹은심장급사의위험요인 ( 급사의가족력, 실신의과거력, 운동부하검사중이상혈압반응, 24시간활동중심전도에서나타난비지속성심실빈맥, 30 mm 이상의과도한심실비후 ) 중 2가지이상이있을경우에 ( 일차예방 ) 제세동기를삽입하였다. 7)8) 삽입된제세동기및설정모든환자들은쇄골하정맥을통하여제세동기삽입술을시행받았다. 삽입된제세동기는 (GEM-VR, Marquis-VR, Medtronic, Minneapolis, USA and Photon-VR/DR, Atlas- VR, Atlas-DR, Epic-VR, Epic-DR, St. Jude, Sunnyvale, California, USA) 통상의방법으로설정되었다. Table 1. Indications for ICD implantation Pt. No Secondary Indication Primary SCD VT Family Hx NSVT EPS EchoCG Syncope TMT 01 + + ATP setting 02 + 03 + 04 + 05 + + 06 + + + 07 + + 08 + + 09 + + 10 + 11 + + + 12 + + 13 + + + 14 + 15 + 16 + + 17 + + 18 + + 19 + 20 + 21 + + 22 + + + 23 + + + Total 3 11 5 3 4 1 6 2 14 9 8 Indications for ICD insertion for each patient are listed in this table. In some patients, inducible VT during electrophysiologic study was included as an indication of ICD insertion for primary prevention (This was considered as an indication in previous studies, 10) but the relevance of invasively induced arrhythmias appeared to be limited in successive stidies 13) ). ICD: implantable cardioverter-defibrillator, Pt. No.: the number of patient, SCD: sudden cardiac death survivor, VT: ventricular tachycardia, Family Hx: family history of sudden cardiac death, NSVT: non-sustained ventricular tachycardia during 24 hour Holter monitoring, EPS: ventricular tachycardia induced during electrophysiologic study, EchoCG: excessive LV wall hypertrophy on echocardiography, TMT: abnormal BP response to treadmill test, Secondary: secondary prevention, Primary: primary prevention, ATP: anti-tachycardia pacing setting

576 Hypertrophic Cardiomyopathy and Arrhythmia 심실빈맥의탐지기준은환자의부정맥특징에따라설정하였다. 설정심실빈맥구역은통상적으로분당 150~180 회의범위로, 심실빈맥탐지심박수는 12로설정하였고, 일반적으로빈맥주기의변동이 80 msec 이내로일정하고, 심장내전기도형태가동율동에서의전기도형태와비교하여 60% 이하의유사성 (morphology discriminant) 을보이며, 갑작스럽게발생할경우 (100 msec 이상의박동주기변화 ) 심실빈맥으로정의하였다. 통상적으로심박동수가분당 180~ 200 회이상이면심실세동으로인식하고제세동쇼크가시행되도록제세동기를설정하였고, 이전에심방세동의과거력이있거나운동시빠른동율동이나타나는경우에는설정을분당 200 또는 220 회로올리도록하였다. 항빈맥조율 (antitachycardia pacing) 은탐지된빈맥의박동주기 (cycle length) 의 85% 로 8~10 개의자극이 2~3번시도되는것으로설정되었다. 이전에심실빈맥의과거력이있었던환자 11 명중 6명에대하여항빈맥조율설정을하였다 ( 환자 1, 7, 8, 9, 17, 18) (Table 1). 나머지 5명의환자들은 ( 환자 2, 3, 4, 14, 15) (Table 1) 심실빈맥의과거력이있었지만, 박동주기가매우빠르거나심실빈맥당시혈압이불안정하여항빈맥조율의효과가적을것으로생각되었기때문에설정을하지않았다. 그외에도심실빈맥의가능성이있던환자 6, 11에게항빈맥조율을설정하여 ( 환자 6은실신의과거력이있었고, 환자 11은 24시간활동중심전도에서비지속성심실빈맥이있었음 ), 총 8명에서항빈맥조율을설정하였다. 이후 3개월마다정기적으로환자들에게서제세동기의방출혹은과감응 (oversensing) 등이있었는지확인하였다. 심실내전기도분석연결간격 (coupling interval) 은제세동기전기도에서기록된동성박동 (sinus beat) 과조기수축 (premature beat) 간의간격으로정의하였다. 항빈맥조율혹은제세동후연속적으로 5개의동성맥이기록되면심실빈맥이종료되고동성맥이회복된것으로인식하도록하였다. 적절한쇼크 (appropriate shock) 는심실빈맥 / 세동에대하여제세동기에서상응하는치료가시행되는것으로정의하였고, 부적절한쇼크 (inappropriate shock) 는심실빈맥 / 세동이아닌경우 ( 심방세동등의상심실빈맥, 인공물, 잡음감지, 이중감지등 ) 에제세동기에서이를잘못분석하여치료가시행되는것으로정의하였다. 9) 결 과 1996 년 4월부터 2006 년 2월까지서울아산병원에서제세동기를삽입하였던환자는총 135 명이었다. 이들환자에서의원인심질환은심근경색후심실빈맥 (30%, 40명 ), 브루가다증후군 (26%, 35명 ), 비후성심근증 (17%, 23명 ) 이대부분을차지하였다 (Fig. 1). 본연구에서는이들제세동기를삽입한비후성심근증환자 23명을대상으로이들의임상적특성, 제세동기쇼크치료시의심장내전기도분석을통하여이들환자에서의심실빈맥의특성을고찰하고자하였다. 대상환자 23명의남녀비율은 16:7이었고, 평균나이는 53.0± 10.9 세였다 (Table 1, 2). 총 23명의환자중 9명에서일차예방목적으로제세동기를삽입하였고 ( 반복된실신 6명, 급사의가족력 4명, 비지속성심실빈맥 3명, 심초음파에서의과도한좌심실비대는 1명, 운동부하에서혈압의이상반응 2명, 전기생리학검사에서심실빈맥이유발된환자 4명중 2명에서과거의적응증으로서제세동기삽입 ), 10) 14 명에서는 2차예방의목적 ( 이전의심실빈맥 11명, 심장급사 3명 ) 으로제세동기를삽입하였다. 전기생리학검사에서심실빈맥이유발되었던환자 4명중 (Table 1) ( 환자 5, 12, 13, 23) 1 명 ( 환자 5) 에서추적관찰중심실빈맥이발생하였다 (Table 1, 3). 비후성심근증으로제세동기를삽입한환자에서추적관찰중기록된심실부정맥은심실빈맥이 51회, 심실세동이 1회였다. 51회의심실빈맥중 45회에서적절쇼크 (appropriate shock) 가 6명 (26%) 에서시행되었고 ( 나머지 6회는자발종료됨 ), 1회의심실세동은제세동기치료가시행되기전에저절로리듬이동성으로회복되었다 (Table 3). 부적절쇼크 (inappropriate shock) 는 23명중 7명 (30%) 에서총 25회있었다. 이들부적절쇼크의가장흔한원인은심방세동이었으며 (7 명 Fig. 1. The Indications for ICD implantation at Asan Medical Center. Post-MI VT, Brugada syndrome, HCM were the three major causes of ICD implantation at Asan Medical Center. In 17% of total ICD implantations, HCM was the underlying heart disease. MI: myocardial infarction, VT: ventricular tachycardia, HCM: hypertrophic cardiomyopathy, DCM: dilated cardiomyopathy, ARVD: arrhythmogenic right ventricular dysplasia, Post-op: post-operation. Table 2. Characteristics of the study subjects Subject characteristics Number of subjects 23 Post MI VT Brugada syndrome H-CM D-CM Sarcoidosis Long QT syndrome ARVD Idiopathic V.Fib Post-op VT Restrictive Others Female 07 Male 16 Mean age (yrs) 53.0±10.9* Follow up period (days) 561 (range 16-2,694) LV wall thickness (mm) 20.5±5.7* LV EF (%) 57.0±12.2* *Mean±standard deviation. LV: left ventricle, LVEF: left ventricular ejection fraction

Jong Wook Kim, et al. 577 Table 3. The type of ventricular tachyarrhythmias and the ICD discharges Pt. No Prevention VT VF Defibrillation shock ATP ATP setting Spontaneous termination 1 2 17 0 03 14 + 0 2 2 02 0 02 00-0 3 2 23 0 23 00-0 4 2 02 0 01 00-1 5 1 04 0 01 00-3 6 1 03 1 00 01 + 3 Total 51 1 30 15 2 7 Ventricular tachyarrhythmias occurred in 6 patients. The types of ventricular tachyarrhythmia and ICD discharge are described in this table. 4 patients received 30 defibrillation shocks and 2 patients received 15 antitachycardia pacings. Except for one case of overdrive acceleration which needed defibrillation shock for termination in patient number 1, all ATPs successfully terminated VTs. ATP setting was not done in patient number 2 due to LV outflow tract obstruction and mitral regurgitation with possible hemodynamic instability during ATP, in patients number 3 and 4 due to presence of fast VT, and in patient number 5 because there had been no previously documented VTs. ICD: implantable cardioverter-defibrillator, Pt. No.: the number of patient, VT: ventricular tachycardia, VF: ventricular fibrillation, ATP: antitachycardia pacing Table 4. Summary of ventricular arrhythmia Pt. No Abrupt onset/ termination VTCL variation CI variation Overdrive acceleration 1 + + + + 2 + - - 3 + - + 4 + - - 5 + + - 6 + + + In every patient, the onsets and terminations of VT were abrupt. Overdrive acceleration was noted in one patient (patient number 1). Pt. No.: the number of patient, VTCL: ventricular tachycardial cycle length, CI: coupling interval, VT: ventricular tachycardia 중 5 명 ), 다음으로는상심실성빈맥 (supraventricular tachycardia, 7명중 3명 ) 이었다. 이들부적절쇼크를예방하기위해서 β-blocker 를사용하여심박동수를낮추거나, 심실세동의심박동수탐지기준을통상의분당 180~200 회에서그이상으로올리거나, 심실빈맥의 rate stability 기준을적용하였다. 일차예방목적으로제세동기를삽입한환자 9명중삽입의적응증이 2개였던환자는 6명이었고, 3개였던환자는 3명이었다. 심실부정맥은이중 2명 (22.22%) 에게서발생하였는데, 이들은모두적응증이 2개였던환자였다. 또한심실부정맥은이차예방목적으로삽입한환자 14명중 4명 (28.57%) 에게서발생하였다. 항빈맥조율치료가설정되었던 8명의환자들중 2명의환자에서심실빈맥에대하여항빈맥조율치료가시행되었다. 이중 1명에서는조율치료후박동주기가평균 333± 27 msec 에서평균 294±22 msec 으로감소되는초과박동성가속 (overdrive acceleration) 이발생하였고 (Fig. 4), 심실빈맥종료에실패하여제세동이시행되었다 (Table 1, 3, 4) ( 환자 1). 이경우를제외하고는, 모든항빈맥조율치료가시행되었던경우에서심실빈맥이성공적으로종료되었다. 제세동기에기록된심실성부정맥의심장내전기도기록을통해심실성빈맥의특성을고찰하였다. 매심실빈맥에대 하여빈맥첫박동의연결간격 (coupling interval, CI) 과심실빈맥박동주기 (ventricular tachycardial cycle length, VTCL) 를측정하였을때, 동일환자에서도변이가심하였다 (Fig. 2, 3). 충분한횟수의심실빈맥이발생하지않았던환자 2, 4에서는자료를분석하기가어려우나반복적인심실빈맥이나타났던환자들 ( 환자 1, 3, 5, 6) 에서는심실빈맥박동주기및연결간격이심실빈맥발생시마다다양한양상을보였다 (Table 4) (Fig. 3). 고 찰 본연구에서는비후성심근증으로제세동기를삽입한환자의임상적특성과장기적인추적관찰중나타난제세동기치료의현황을분석하였으며, 아울러제세동기에기록된심장내전기도를통하여이들환자에서의심실빈맥의특성을고찰하였다. 제세동기를삽입한 135명의환자중비후성심근증이차지하는비율이 23명 (17%) 으로서, 심근경색후심실세동및브루가다증후군다음으로높아, 우리나라에서비후성심근증은제세동기삽입의중요한적응질환임을알수있었다. 비후성심근증에서는심장급사의위험이높은것으로알려져있으며, βblocker, sotalol, amiodarone 등의항부정맥제의효과에대한무작위대조군연구는없는실정이다. 7) 이에비하여제세동기는비후성심근증급사의이차예방은물론고위험군환자에서의일차예방에서도심장급사의위험을줄일수있는것으로보고되었다. 2-6) 본연구는비후성심근증환자들에서제세동기삽입후장기간의추적관찰결과를보고하였다. 고위험비후성심근증을대상으로총 23명의환자를대상으로제세동기가삽입되었고, 이중 6명 (26%) 에서제세동기방출및심실부정맥이관찰되었으며, 이들심실부정맥은심실빈맥이대부분 ( 총 52 회중 51회, 98%) 이었다. Maron 등 2) 은 128 명의비후성심근증환자를대상으로평균 3.1 년간추적관찰한결과일차예방의목적에서연간 5%, 이차예방의목적에서는연간 11% 의

578 Hypertrophic Cardiomyopathy and Arrhythmia 비율로적절한제세동기의쇼크방출이있었다고보고하였다. 본연구에서는 23명을대상으로평균 1.95 년간추적관찰하였고 ( 일차예방 2.31 년, 이차예방 1.72 년 ) 일차예방목적으로삽입한환자 9명중 2명 (22.22%, 연간 9.61%), 이차예방목적으로삽입한환자 14명중 4명 (28.57%, 연간 16.61%) 에서심실부정맥이발생하였다. 이러한결과를통해심장급사의위험도가높은비후성심근증환자들에서위험도의적절한판별을통해제세동기를삽입하는것의중요성을확인할수있었다. 2)5)6) 심실빈맥은 90% 이상통증이없는항빈맥조율로종료시킬수있다. 물론제세동또한심실빈맥을종료시킬수는 있지만, 항빈맥조율없이바로고통스러운제세동을시행하는것은환자의삶의질을저하시킬수있다. 11) 본연구에서의관찰결과비후성심근증으로제세동기를삽입한환자에서의심실부정맥은임상상에관계없이심실세동이아닌심실빈맥이주된원인이었다. 또한제세동기삽입당시항빈맥조율치료설정을하지않았던 15명의환자들의추적관찰결과 3명 (20%) 에서심실빈맥이발생하였다. 따라서이전에심실빈맥의과거력이없었던환자에서도처음제세동기삽입시우선적으로항빈맥조율설정을하는것이향후치료에있어서유리할것임을알수있었다. 약 30% 의환자 (23 명중 7명 ) 에서총 25 회의부적절쇼크가 A B C Fig. 2. A marked variation in the coupling interval and ventricular tachycardial cycle length (Patient number 3). The panel A, B, C show 3 intracardiac electrograms recorded from patient number 3 during different VT events. The coupling intervals were 531, 875, 805 msec respectively (indicated as double-headed arrows), and the mean VT cycle lengths were 370, 336, 429 msec respectively for each episode. Within the same patient, coupling intervals and VT cycle lengths were highly variable. VT: ventricular tachycardia. 450 1000 900 400 800 VTCL (msec) 350 CI (msec) 700 600 300 500 400 250 300 1 2 3 4 5 6 1 2 3 4 5 6 Patient Patient Fig. 3. Distribution of coupling intervals and ventricular tachycardial cycle lengths. Coupling intervals and VT cycle lengths were measured by analyzing intracardiac electrograms recorded on ICDs. Coupling intervals and VT cycle lengths were highly variable within each patient. VTCL: ventricular tachycardial cycle length, CI: coupling interval, VT: ventricular tachycardia, ICD: implantable cardioverter-defibrillator.

Jong Wook Kim, et al. 579 Fig. 4. An example of overdrive acceleration in patient number 1. An example of overdrive acceleration is shown. The VT cycle length is changed from an average of 333±27 msec to 294±22 msec after anti-tachycardia pacing. This was subsequently terminated by a defibrillation shock (not shown on the figure). VT: ventricular tachycardia. 있었다. 이들부적절쇼크의가장흔한원인은심방세동 (7 명중 5명 ) 및상심실성빈맥 (supraventricular tachycardia, 7 명중 3명 ) 이었다. 이들부적절쇼크를줄이기위해서 β-blocker 를사용하여심박동수를낮추거나, 심실세동의심박동수탐지기준을통상의분당 180~200 회에서그이상으로올리는방법, 또는심실빈맥의 rate stability 기준을적극활용하는방법이사용되었다. 심실빈맥의초과박동성심박조율 (overdrive pacing) 에대한반응은재설정 (resetting), 초과박동성억제 (overdrive suppression), 초과박동성가속 (overdrive acceleration), 종료 (termination) 등 12) 으로분류되고이러한반응을분석함으로써부정맥의원인기전및항빈맥조율치료의역할을추정해볼수있다. 자동능의항진에의하여나타나는빈맥은심조율에의하여시작되거나종료되지않으며, 초과박동성억제를보이는것으로알려져있다. 방아쇠성활동 (triggered activity) 은지연성후탈분극 (delayed afterdepolarization) 에의한것으로, 고속조율후초과박동성가속을나타낸다. 가속된후이러한리듬은점차적으로원래있던주기길이 (cycle length) 를회복하거나, 점차느려지면서종료된다. 초과박동성심박조율에대한회귀성빈맥의반응은재설정 (resetting), 종료또는가속화되는것으로알려져있다. 본연구에서관찰된심실빈맥은항빈맥조율에대하여재현성있게종료되고, 빈맥의시작이서서히시작되기보다는 (warm-up) 급성개시를보이는점등에서심실빈맥의기전이자동능의항진보다는회귀기전또는방아쇠성활동에의한것임을시사한다. 12) 한정된숫자의일부환자의심실빈맥에대한분석으로전체비후성심근증에서의빈맥의기전을일반화하는것은무리가있을것으로생각되나, 본연구에서심실빈맥박동주기및연결간격이동일환자에서도다양 한분포를보이고, 항빈맥조율에의하여재현성있게빈맥의종료가나타나며, 또한일부환자에서기록된초과박동성가속을고려할때비후성심근증에서의심실빈맥은방아쇠기전이가장중요한역할을할것으로추정된다. 비후성심근증에서나타나는빈맥이일정한연결간격이나빈맥주기를보인다면부정맥의유발부위가국소에한정되거나일정한회귀회로를통하여일어날가능성을시사하고, 장차도자절제술을이용한치료의적용을고려하여볼수도있겠으나, 본연구의결과비후성심근증은비후된심근내의다양한병소에서빈맥이기원할가능성이많을것으로추정되므로도자절제술의적용이용이하지는않을것으로유추된다. 요약 배경및목적비후성심근증은 500명중 1명의비교적높은유병률을가진유전성질환이다. 비후성심근증이있는경우심실부정맥이잘발생하는것으로알려져있고, 고위험환자들에게는제세동기삽입이심장급사를줄일수있는것으로밝혀져있다. 본연구에서는비후성심근증으로제세동기삽입술을시행받은환자들에서장기간추적관찰시나타나는부정맥과이부정맥의특성을고찰하고자하였다. 방법 1996 년 4월에서 2006 년 2월까지 23명의비후성심근증을가진환자들을대상으로제세동기를삽입하였다. 제세동기는 9명에서일차예방의목적으로삽입되었고, 14명에서이차예방의목적으로삽입되었으며, 이들의임상양상및추적관찰기간중에발생한부정맥의심장 내전기도를분석하였다.

580 Hypertrophic Cardiomyopathy and Arrhythmia 결과 561 일간의중앙추적관찰기간동안 ( 범위 16~2,694) 총 51회의심실빈맥이 6명의환자에게서발생하였다. 반면심실세동은 1회발생하였다. 적절쇼크는 6명에서 45회 (64.2%) 발생하였고, 부적절쇼크는 7명에서 25 회 (35.7%) 발생하였다. 적절쇼크중제세동쇼크는 5명에서 30회있었고, 항빈맥조율은 2명에서 15회있었다. 심실빈맥의발생은제세동기삽입전심실빈맥이진단된경우뿐만아니라심실빈맥이기록되지않은경우에도높은빈도로나타났다. 제세동기의전기도분석에서연결간격및심실빈맥박동주기는각각의환자들내에서변이가심하였으며, 1명의환자에서는초과박동성가속이관찰되었다. 결론임상양상에관계없이, 비후성심근증환자들에서심실빈맥이심실세동보다더높은빈도로발생하였으며, 이는제세동기삽입전심실빈맥의유무와관계없이발생하였다. 심실빈맥이주된심실부정맥이었으므로, 이전에심실빈맥의과거력이없던환자에서도항빈맥조율설정이중요할것으로생각된다. 심장내전기도의분석결과 ( 연결간격및빈맥주기의변화, 조율치료에대한반응 ) 방아쇠성활동이비후성심근증에서심실빈맥발생의주된발생기전으로추정된다. 중심단어 : 비후성심근증 ; 심실빈맥 ; 제세동기 ; 심장급사. Acknowledgments 서울아산병원심장내과권정해간호사님께서많은도움을주셨습니다. REFERENCES 1) Jeong JW. Hypertrophic cardiomyopathy. Korean Circ J 2002; 32:7-14. 2) Maron BJ, Shen WK, Link MS, et al. Efficacy of implantable cardioverter-defibrillators for the prevention of sudden death in patients with hypertrophic cardiomyopathy. N Engl J Med 2000; 342:365-73. 3) Kim DH, Kim SY, Lee KH, et al. Follow up of a group of patients with automatic implantable defibrillator. Korean Circ J 2005;35:69-83. 4) Lee DI, Kim AS, Kim JY, et al. Implantable cardioverter-defibrillator (ICD) therapy: initial clinical experience in 6 patients. Korean Circ J 1999;29:999-1015. 5) Kuck KH, Cappato R, Siebels J, Ruppel R. Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest: the Cardiac Arrest Study Hamburg (CASH). Circulation 2000;102:748-54. 6) Maron BJ, Estes NA 3rd, Maron MS, Almquist AK, Link MS, Udelson JE. Primary prevention of sudden death as a novel treatment strategy in hypertrophic cardiomyopathy. Circulation 2003;107:2872-5. 7) Jayatilleke I, Doolan A, Ingles J, et al. Long-term follow-up of implantable cardioverter defibrillator therapy for hypertrophic cardiomyopathy. Am J Cardiol 2004;93:1192-4. 8) Begley DA, Mohiddin SA, Tripodi D, Winkler JB, Fananapazir L. Efficacy of implantable cardioverter defibrillator therapy for primary and secondary prevention of sudden cardiac death in hypertrophic cardiomyopathy. Pacing Clin Electrophysiol 2003; 26:1887-96. 9) Kim YH, Kim JS. Clinical characteristics in patients with implantable cardioverter-defibrillator (ICD). Korean Circ J 2004; 34:395-404. 10) Fananapazir L, Chang AC, Epstein SE, McAreavey D. Prognostic determinants in hypertrophic cardiomyopathy: prospective evaluation of a therapeutic strategy based on clinical, Holter, hemodynamic, and electrophysiological findings. Circulation 1992; 86:730-40. 11) Sweeney MO, Wathen MS, Volosin K, et al. Appropriate and inappropriate ventricular therapies, quality of life, and mortality among primary and secondary prevention implantable cardioverter defibrillator patients: results from the Pacing Fast VT REduces Shock ThErapies (PainFREE Rx II) trial. Circulation 2005;111:2898-905. 12) Josephson M. Clinical Cardiac Electrophysiology, Techniques and Interpretations. 2nd ed. Lea & Febiger. p.502-6. 13) Behr ER, Elliott P, McKenna WJ. Role of invasive EP testing in the evaluation and management of hypertrophic cardiomyopathy. Card Electrophysiol Rev 2002;6:482-6.