Slivia G Priori教授  美国纽约大学莱昂医院

　　<International Circulation>: Inherited arrhythmias cause great harm and have high death rates， requiring early diagnosis and treatment. What are the clinical types of inherited arrhythmias?

　　Prof. Priori: The inherited arrhythmias represent a substantial part of sudden cardiac death occurring in young people. They encompass all ages from sudden infant death syndrome (first 9 months) all the way up to an age usually defined as younger than 45 (45 is when the most important causes of sudden death start becoming this chemical disease of heart failure). Within this age range， there are different genetic defects that may predispose different individuals to sudden cardiac death. Some are cardiomyopathies， where the heart is abnormal， but others are more subtle and difficult to diagnose， as they are only related to abnormalities that you can see on ECG exams while the structure of the heart is normal. These diseases are called “channelopathies” meaning disease of the ion channels and are predominantly abnormality of the electrical component of the heart. Why is it important to identify these people? As you said， fatality rates are very high if these conditions are not identified and treated. The good news is that there is treatment available for the disease. Cardiologists must try to verify these diseases by careful analysis of electrocardiographs (ECG).

　　The document recently put forth by the Arrhythmia Scientific Society of the World， composed of the American Heart Rhythm Society， European Association of Heart Rhythm and Asian-Pacific Heart Rhythm Society， encompassing a common opinion of the entire world to set diagnostic criteria and management strategies for these patients. I think for the clinician， now is a good time to receive this document and start refreshing the concept of how to make these diagnoses.

　　I would like to mention the three most common of these conditions. (1) Long QT syndrome is considered a disease prevalent in 1 out of 2500 people， not an incredibly rare disease. Its manifestation is syncope occurring during stress or emotion in young people (mean age of first event: 12 years). You diagnose this condition because the ECG shows a prolongation of the QT interval that is above 440ms in males and 460msin females. It’s important to diagnose this condition because if you treat these patients with beta-blockers， you can dramatically reduce mortality so that only a small percentage of these patients will have the need for an implantable defibrillator (ICD). What the new guidelines say is to be very skillful in identifying these children who are fainting during emotional response activity and to treat them promptly with beta-blockers.

　　Another condition quite prevalent， especially in Asian populations， is called (2) Brugada syndrome. Abnormal ECG characterizes Brugada syndrome with ST segment elevation in B1， B2 and B3. These new guidelines really provide good support for the clinician on how the measurements and positioning of the leads should be made to correctly diagnose Brugada syndrome. This is not a pediatric disease; it strikes mainly men aged between 30 and 60 years when sudden cardiac death may occur at night. It’s interesting that for Brugada， fever is often a factor that predisposes to sudden cardiac death in the affected individual. Treatment for Brugada is mainly the use of an implantable defibrillator， very different from long QT， where we can use drugs. There is an experimental clinical study， but it has not yet concluded， testing the effect of quinoline and all the sodium channel blockers and anti-arrhythmic drugs that seem to be effective for these conditions.

　　The last disease I would like to mention is called (3) CatecholaminergicPolymorphic Ventricular Tachycardia (CPVT)， another disease that strikes young kids. Again， cardiac arrest is the consequence of an arrhythmia triggered by stress or emotion. It has a very similar manifestation to long QT syndrome， but when you inspect the ECG you find a normal QT. Therefore， the way to diagnose this condition is by performing an exercise stress test. The key message for the guideline documents is that physicians should really consider doing an exercise stress test whenever young people have repeated episodes of fainting during exercise or emotional response. Again， this condition can be treated with beta-blockers and sometimes， a combination of beta -blockers and sodium channel blockers may also prevent the need for ICD.

　　《国际循环》：遗传性心律失常危害大、致死率高，需要早期诊治。遗传性心率失常有哪些主要的表现类型？

　　Priori教授：遗传性心率失常是导致年轻人心脏性猝死的重要原因，可见于各年龄段，从婴儿猝死综合征（前9个月）一直到45岁以下人群。45岁是猝死的重要原因转变为心力衰竭的时段。在这个年龄范围内，不同遗传缺陷可导致不同个体发生心脏性猝死。有些是心肌病所致的心脏异常，有些则仅见心电图异常而心脏结构正常因而更为隐蔽难以诊断。这些疾病被称为离子通道疾病，主要存在心脏电元件异常。为什么识别这些患者具有重要意义？正如你所说的，如果得不到及时的发现和治疗，这些患者的死亡率是非常高的。目前有个好消息，就是我们有了治疗这种疾病的方法。心脏病学家必须对心电图（ECG）结果进行仔细分析来验证这种疾病。由美国心律学会、欧洲心律协会及亚太心律学会组成的世界心律失常科学学会最近发布了整个世界对上述患者之诊断标准及管理策略的共识。我认为，对临床医生而言，是学习这份文件、更新上述疾病诊断理念的好时机。我在此想介绍一下遗传性心律失常最常见的三种类型。①长QT综合征，每2500例人口中就有一例，并不罕见。其常表现为年轻人（首次发病平均年龄为12岁）在压力或情绪激动时发生晕厥。ECG示QT间期延长（男性>440 ms，女性>460 ms）则可诊断。该病的诊断具有重要意义，因为确诊后及时应用β受体阻滞剂治疗不但能显著降低患者的死亡率，还能减少需要应用植入式除颤器（ICD）的患者比例。新指南就如何识别在有情绪反应活动时易晕倒的儿童做了详细指导，并推荐及时应用β受体阻滞剂。②Brugada综合征，非常常见，尤其是在亚洲人群中。其ECG以V1～V3导联ST段抬高为特征。新指南就如何测量和放置导线以正确诊断该病作了非常好的指导。该病不是儿科疾病，其发病年龄为30～60岁，夜间易发生心脏性猝死。非常有趣的是，发热是导致该病患者易发生心脏性猝死的常见原因。该病的治疗主要是应用植入式除颤器，这与长QT综合征不同，长QT综合征可采用药物治疗。目前已经有实验性研究正在评估喹啉、钠离子通道阻断剂及抗心律失常药物对该病的疗效，但尚未得出结论。③儿茶酚胺敏感性多形性室性心动过速（CPVT ），多于幼儿期发病，在压力及情绪异常时易发生心脏骤停。其临床表现与长QT综合征相似，但ECG所示QT间期正常。因此，诊断该病主要是通过运动负荷试验。新指南强调，一旦年轻人在运动或情绪反应时出现反复发作的晕厥时应考虑行运动负荷试验。CPVT的治疗也是应用β受体阻滞剂，有时采用β受体阻滞剂和钠离子通道阻滞剂联用也可预防需要行ICD的发生。