Case Conference

Chief complaint：     Syncope in the morning of the date of admission Brief history: The 42 year-old man has been quite well until Aug. 3, 1999 when he experienced the first attack of syncope in the morning. He was found to have labored breath and convulsion by his wife at AM 5:00 on Aug 8. He was brought to the emergency room where electrocardiogram revealed ventricular fibrillation. He was treated with amiodarone 200mg bid. Despite of the therapy, another episode of convulsion occurred in the morning of Sep 3. He was sent to the emergency room again where recurrent ventricular fibrillation (fig 1) was noted and cardiodefibrillation was successfully applied. The electrocardiogram done after defibrillation was shown in fig 2. Then he was transferred to our hospital. Reviewing the history, the patient denied any symptoms suggesting coronary artery disease. At our hospital, physical examinations revealed that blood pressure was 110/70 mmHg, body temperature was 36.2ºC, and pulse pressure was 20/min. The chest was symmetrically expanded and breathing sound was clear. The chest wall had the marker of the DC shock. The heart had regular beats without murmur. The abdomen was soft. His extremities were freely movable. The neurological examination was normal. Course and Treatment: His biochemistry and complete blood count were within normal limit. No elevation of cardiac enzyme was found. The electrophysiologic study showed inducible non-sustained polymorphic ventricular tachycardia. The signal-averaged electrocardiogram showed positive late potential. The cardiac catheterization performed on Sep 6 showed normal contractility of both ventricles. Cardiac magnetic resonance image revealed increased signal intensity at the myocardium at right ventricular outflow tract. The challenge test for inducing arrhythmias yielded positive J wave on eletrocardiogram. An ICD was successfully implanted on Sep 10, 1999. He was discharged on a stable condition. However, frequent ICD defibrillations were complained of which made him discomfortable and frustrated. He removed the ICD by himself at the night of Nov 3, 1999. He was admitted to our hospital later for wound infection. Blood culture showed Aeromonas species. Debridement was performed with secondary closure. Unfortunately, he experienced the attack of ventricular tachycardia and ventricular fibrillation in the morning of Nov. 28. After defibrillation, he regained his vital signs.

繼續教育考題 1. (A) What is the rhythm of patient as in Fig 1? A ventricular fibrillation B atrial fibrillation C paroxysmal supraventricular tachycardia D Sinus tachycardia 2. (C) How to manage the rhythm mentioned in Q1 at ER first? A Carotid massage B Atropine C Check lead, then DC shock, 200J, unsynchronized D On central venous line 3. (A) What is the possible underlying disease of the patient? A Idiopathic ventricular tachycardia B coronary artery disease C Seizure D organic heart disease 4. (D) If a patient is suspected to be a case of Brugada syndrome, which test is not necessary? A Procainamide test B Electrocardiogram (Holter and 12 lead) C Electrophysiological studies D Brain MRI 5. (D) Which are not the characteristics of Brugada syndrome? A Asia origin: more B Medical history: unremarkable C Peak age: fourth decade D Female dominate 6. (C) Which is the presentation of Brugada syndrome (please see fig 2)? A LBBB B QTc prolonged C Transient normalization D Precordial ST depression 7. (B) If a patient was a suspected victim of Brugada syndrome, but his ECG is normal, what kind of drugs should be used as a challenge test? A Class IB B Class IA C Ca-blocker D Alpha-blocker 8. (A) Which is not the difference between long QT syndrome and Brugada syndrome? A Channel defect B Sex difference C QTc duration D Attack timing 9. (D) How to treat the Brugada syndrome according to the present trend? A Quinidine B ß-blocker C Amiodarone D ICD 10. (B) What is the molecular defect of the Brugada syndrome? A Ca channel B Na channel C K channel D Cl channel

病例分析及答案解說 病例分析: 42歲男性，沒有特別的underlying disease，此次來院的主訴是清晨時，被發現暈厥及抽慉的症狀。 可考慮非心因性及心因性，考慮病人的情況，心因性有可能。在心因性的原因，病人並無心臟衰竭、 瓣膜疾病及胸痛之過去史，所以心律不整應加以考慮。因此病人在發作的心電圖及症狀對此病人至為重要。 在Sudden cardiac death (SCD)中約有10〜20﹪係normal structural heart, 其中主要包括 Long QT syndrome, WPW syndrome 和Brugada syndrome(EKG表現 RBBB + ST elevation in V1-3)。 Brugada syndrome 係在1992年由Dr. Brugada 最早提出，此病主要發生再東南亞及日本之年輕男性，易有SCD。 答案解說: No brain problem in the Brugada syndrome, so brain MRI is not necessary. Brugada syndrome: male more than female by far. ECG: RBBB; precordial elevation in V1, 2; QTc: almost normal Class IA could increased ST elevation in the Brugada, so it could be a challenge test. The long QT syndrome and Brugada syndrome: Na channel defect ICD could prevent sudden death in these patients. No drug was proved to be effective in preventing sudden death in these patients at the present.) Mutations have been identified in the cardiac sodium channel gene (SCN5A). Top of Page