Original Articles Korean Circulation J 2002;329:798-806 선천성 QT 연장증후군의임상적특성에대한고찰 김정호 1 남기병 1 김현국 1 이경석 1 한기훈 1 최기준 1 고재곤 2 박인숙 2 김유호 1 Clinical and Electrocardiographic Features of Patients with Congenital Long QT Syndrome Jung-Ho Kim, MD 1, Gi-Byoung Nam, MD 1, Hyun Kuk Kim, MD 1, Kyoung-Suk Rhee, MD 1, Ki Hoon Han, MD 1, Kee-Joon Choi, MD 1, Jae Kon Ko, MD 2, In-Sook Park, MD 2 and You-Ho Kim, MD 1 1 Department of Internal Medicine, 2 Pediatrics, Ulsan University College of Medicine, Asan Medical Center, Seoul, Korea ABSTRACT Background and ObjectivesCongenital long QT syndrome LQTS is characterized by the prolongation of the QT interval, frequent episodes of syncope and Torsades de Pointes TdP. The clinical features and electrocardiographic findings in Korean patients with LQTS have not been reported. Subjects and MethodsWe retrospectively analyzed the clinical characteristics, ECG features and response to treatments in 11 patients 6 men, 5 women with congenital LQTS. ResultsThe mean age at the time of the first episode was 19.422.6 years old range170 years. Clinical presentations were syncope, seizure or sudden cardiac death SCD. Predisposing factors included exercise, sudden startle or sleep. Only three patients showed familial histories of syncope or SCD. The average QTc interval was 0.580.05 second range0.470.61 seconds. T wave morphologies were classified as normal-appearing, broad-based, low amplitude/bifid or late onset. For its management, bblockers were used in 7 patients. In 2 patients, whose clinical events were related with to an increased vagal tone or were aggravated by blocker therapy, mexiletine was prescribed. When bradycardia or AV block was documented, pacemakers were implanted. For 2 patients at high risk of sudden cardiac death, cardioverter-defibrillators were implanted. During a mean follow up period of 23.520.2 months range364 months, symptoms cardiac arrest recurred in 1 patient.conclusioncongenital LQTS is a heterog-eneous disease, showing diverse clinical manifestations, ECG features, and response to pharmacological management. Further research on the genotype-phenotype relationship will refine the management, enabling gene-specific treatment of this life-threatening disease. Korean Circulation J 2002;32 9:798-806 KEY WORDSLong QT syndromeelectrocardiographydeath, suddensyncopearrhythmia. 798
서론 - 대상및방법 결과 임상적특성 Table 1. Clinical characteristics of the study patients No Sexage FHx Provocating factor Structural heart ds Clinical manifestation 01 M21 Isometric exercise Palpitation, syncope, TdP 02 0F430 Sudden startle Palpitation, syncope, TdP 03 0F420 Sleeping resting Aborted cardiac arrest 04 M80 Isotonic exercise Syncope 05 M30 Non-specific Seizure, deafness both 06 F40 Non-specific Aborted cardiac arrest TdP, CAVB 07 M30 Sleeping Small VSD Seizure 08 M12 Isotonic exercise Syncope 09 F60 Non-specific Aborted cardiac arrest 10 M10 Non-specific Seizure 11 F70 Non-specific Palpitation, syncope, TdP TdPtorsades de pointes, LOCloss of consciousness, CAVBcomplete atrioventricular block ICDimplantable cardioverter/defibrillator, FHxfamiliar history, VSDventricular septal defect 799
Fig. 1. Induction of TdP during exercise provocation test. TdP was induced by isometric exercise test chest pressor in patient 1. Tachycardia was not induced after repeated attempts of isotonic treadmill exercise test, while being induced reproducibly by chest pressor. This suggests that tachycardia induction in congenital long QT syndrome is dependent on the type of exercise. TdPtorsades de pointes. - Table 2. ECG characteristics No QTQTc T wave pattern 01 0.660.60 02 0.640.59 Bifid T wave Normal appearing T wave T wave inversion V14 03 0.380.55 Late onset T wave T wave alternans 04 0.470.54 Broad based T wave 05 0.520.65 Broad based T wave 06 0.520.58 Normal appearing T wave 07 0.600.60 Broad based or biphasic T Wave 08 0.370.47 Broad based T wave T wave alternans 09 0.550.66 Normal appearing T wave T wave inversion V14 10 0.470.57 Normal appearing T wave Pseudo 21 AV block 11 0.530.53 Low amplitude T wave AV blockatrioventricular block 검사소견 - 800 Korean Circulation J 2002;329:798-806
심전도상의특징 - 치료및추적관찰기간 Fig. 2. Different patterns of ST-T wave complex in patients with long QT syndrome. Anormal-appearing T wave pattern patient 1, Bbroad-based T wave pattern patient 5, Clow-amplitude bifid T wave pattern patient 2, Dlate onset T wave patient 3. Fig. 3. T wave alternans. Alternation of the T wave amplitude and polarity was recorded during Holter monitoring patient 8. 801
Fig. 4. First degree or 21 pseudo AV block. Functional AV block occurred in the setting of fast atrial rate and dramatically prolonged ventricular replorization as the P waves fell within the T wave Patient 10. Table 3. Treatment and follow-up periods No Treatment Follow-up periods month 01 blocker, ICD 12 02 blocker, ICD 29 03 Isoproterenol, mexiletine 26 04 None F/U loss 05 blocker, ICD refused 05 06 blocker, pacemaker 64 07 Mexiletine, pacemaker 05 08 blocker 03 09 blocker, ICD refused 38 10 Observation 10 11 blocker 43 ICDimplantable cardioverterdefibrillator - 고찰 802 Korean Circulation J 2002;329:798-806
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