微伏级T波电交替对肥厚型心肌病高危人群的预测价值

目的探讨动态心电图分析系统时域法检测微伏级T波电交替（MTWA）对肥厚型心肌病患者恶性室性心律失常及心脏性猝死的预测价值。方法94例肥厚型心肌病患者（观察组）和105例健康人（对照组）接受24h动态心电图检查并作MTVvA检测,分析两年的死亡、晕厥及恶性心律失常的发生情况。结果对照组MTWA95％正常值参考范围〈36μV。对照组MTWA〉36uV的占10．5％。观察组MTWA〉36uV的占553％。对照组无心血管事件发生;观察组发生恶性心律失常29例,MTWA〉36uV对恶性心律失常诊断的敏感性793％,特异性55．4％;阳性预测值442％,阴性预测值857％。结论MTWA异常的肥厚型心肌病患者发生恶性室性心律失常及心脏性猝死的危险性增加。     

药物与手术治疗肥厚型心肌病伴室壁瘤的疗效对比分析

目的探讨肥厚型心肌病伴室壁瘤的发生率、临床特点、治疗和预后。方法连续收集在我院诊治的1844例肥厚型心肌病患者,通过超声、心脏核磁和左室造影筛选室壁瘤,对其临床资料进行分析和随访。结果肥厚型心肌病合并室壁瘤患者22例(患病率1.1%),其中11例患者反复发作持续性室速,9例伴有附壁血栓。随访4.5±3.0年后,18例无手术患者左心扩大、收缩功能下降,其中11例发生心脏性死亡、进展性心衰或卒中;另4例经室壁瘤切除术后左室功能逆转,无不良事件发生。2例瘤内有存活心肌的室壁瘤患者发生心脏性猝死,另1例手术后存活。结论肥厚型心肌病伴室壁瘤的主要临床表现是持续性室速和附壁血栓,其预后极差,室壁瘤切除术可有效改善预后,而瘤部位存活心肌可能是其心脏性猝死的预测因子和早期手术指征。     

肥厚型梗阻性心肌病的治疗进展

大多数肥厚型梗阻性心肌病（HOCM）患者无症状或仅轻度症状，可不治疗或仅予药物治疗。对5%伴中、重度症状的患者，如药物治疗无效可予介入治疗，包括经主动脉途径的室间隔心肌切开-切除术、经皮经腔间隔心肌消融术及永入性双腔起搏器治疗等，以降低LVOTG并缓解症状。对伴发快速性室性心律失常等猝死高危者或心搏骤停后复苏者应予胺碘酮和（或）ICD作心脏性猝死的一级或二级预防。对伴明显左心房增大的HOCM者应予抗菌素预防感染性心内膜炎。     

肥厚型心肌病的致病机理研究进展

肥厚型心肌病的致病机理研究进展吴晓霞吴加金肥厚型心肌病（ＨｙｐｅｒｔｒｏｐｈｉｃＣａｒ－ｄｉｏｍｙｏｐａｔｈｙ，ＨＣＭ）是一种以不明原因的心肌肥厚、心肌纤维排列紊乱为特征的原发性心肌病，它表现为多样的临床症状，是青少年患者发生心脏性猝死的常见原因，通...     

肥厚型心肌病患者碎裂QRS波与心血管事件风险相关性的研究进展

肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是心血管内科临床中常见的疾病之一,循证医学证据表明HCM亦是导致心脏性猝死的常见原因之一,因此,预测HCM患者的恶性心血管事件风险尤为重要.作为心电学无创指标之一的碎裂QRS波(fragmented QRS complex,fQRS),其产生机制与心肌瘢痕所引起的传导延迟密切相关,因具有测量方便、快捷等优点而受到业界的重视.本文整理分析了2013—2020年HCM伴fQRS患者相关的国内外临床研究及荟萃分析资料,结果提示fQRS可作为HCM患者室性心律失常、心脏性猝死风险等高危心血管事件的预警靶标,且对评估随访患者远期预后有重要的临床意义.     

心肌病与室性心律失常

原发性心肌病是指一类伴有"心脏功能障碍"的心肌疾病。根据WHO基于解剖和生理特点的分类,心肌病可分为肥厚型、扩张型、限制型及致心律失常性右室心肌病四种。其中扩张型、肥厚型以及致心律失常性心肌病与室性心律失常以及心脏性猝死密切相关。最初阶段的心肌病原发性的病理改变以及终末阶段严重的心力衰竭都可以导致严重的室性心律失常或者心脏性猝死。然而,由于病理特点的不同,室性心律失常在这三种心肌病中临床表现及其内含的转归意义也各异。对室性心律失常的处理及心脏性猝死的预防是心肌病治疗的重要方面,这要求对心律失常机制及转归意义具有深刻的理解。循证医学及新的治疗手段诸如射频消融和埋藏式心脏转复除颤器的出现使之更为确切并且有效;而分子心脏病学的发展使从心肌细胞甚至更微观的水平来理解及治疗心肌病成为可能。目前心肌病室性心律失常的处理主要是根据循证医学的证据、患者的具体情况和医务人员的经验而定。     

心肌病与室性心律失常

原发性心肌病是指一类伴有“心脏功能障碍”的心肌疾病。根据WHO基于解剖和生理特点的分类，心肌病可分为肥厚型、扩张型、限制型及致心律失常性右室心肌病四种。其中扩张型、肥厚型以及致心律失常性心肌病与室性心律失常以及心脏性猝死密切相关。最初阶段的心肌病原发性的病理改变以及终末阶段严重的心力衰竭都可以导致严重的室性心律失常或者心脏性猝死。然而，由于病理特点的不同，室性心律失常在这三种心肌病中临床表现及其内含的转归意义也各异。对室性心律失常的处理及心脏性猝死的预防是心肌病治疗的重要方面，这要求对心律失常机制及转归意义具有深刻的理解。循证医学及新的治疗手段诸如射频消融和埋藏式心脏转复除颤器的出现使之更为确切并且有效；而分子心脏病学的发展使从心肌细胞甚至更微观的水平来理解及治疗心肌病成为可能。目前心肌病室性心律失常的处理主要是根据循证医学的证据、患者的具体情况和医务人员的经验而定。     

肥厚型心肌病猝死相关危险因素的研究进展

肥厚型心肌病是一种相对常见的心脏疾病,在普通人群的发病率为0.2%。其临床特征异质性大,但大部分患者的寿命不受影响。尽管如此,心脏性猝死仍然是一部分患者尤其是年轻患者的首发症状。因而,目前迫切需要寻找合理的危险分层方法,将肥厚型心肌病中心脏性猝死高风险的患者鉴别出来。现重点对肥厚型心肌病的相关危险因素做一总结。     

肥厚型心肌病与心源性猝死

肥厚型心肌病是最常见的遗传性心血管疾病,心源性猝死是其最恶劣的并发症,可以在各个年龄段发生。该病为35岁以下青年人和运动员发生心源性猝死的最主要原因。植入式心脏除颤器在预防猝死的发生方面取得了令人瞩目的成果,可以及时终止致命的恶性心律失常,挽救猝死高风险患者的生命。所以,判断哪些患者是心源性猝死的高危人群、哪些患者需进行ICD植入、如何进行危险分层至关重要。现有的危险评估模型仍有很大的局限性,需要更大规模的前瞻性研究及完整的数据采集以对其进行补充完善。     

肥厚型心肌病基因治疗策略的研究进展

肥厚型心肌病（hypertrophic cardiomyopathy,HCM）是一种常染色体显性遗传性心脏病,由肉瘤蛋白突变引起,人群中发病率约0.2%,与杂合突变携带者的左心室肥厚、心肌间质纤维化及心脏舒张功能障碍有关,临床特点具有极度异质性,可表现为恶性心律失常性猝死、心力衰竭和心房颤动等,双杂合突变、复合杂合突变和纯合突变的携带者往往表现出更严重的症状。到目前为止,针对HCM的治疗集中在通过药物干预缓解症状,而非对因治疗。目前人们已发现近40种致病基因,并提出了多种基因治疗策略来消除遗传缺陷以实现HCM对因治疗,包括基因组编辑、外显子跳跃、等位基因特异性沉默、RNA反式剪接和基因替代等,这些技术中的大部分已经在动物或人诱导的HCM多能干细胞模型中进行了有效性及安全性测试。本文就HCM基因治疗策略的最新研究进展进行综述。     

Role of invasive EP testing in the evaluation and management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an inheritable condition that may cause sudden death in the absence of significant symptoms or adverse morphological features. Therefore, there is a need for identification of those patients at sufficiently high risk to warrant prophylactic treatment.Risk stratification for primary prevention of sudden death has relied upon non-invasively derived markers of risk: syncope; a family history of premature sudden death; nonsustained ventricular tachycardia on Holter; abnormal blood pressure response to exercise; and severe left ventricular hypertrophy. The presence of two or more risk factors is associated with a 6-year sudden death survival rate of 72% (56–88%), justifying the consideration of prophylactic therapy. The 6-year sudden death survival rate in patients with one or no risk factors is 94% (91–98%). In these individuals the context and severity of the risk factor may guide the decision for prophylaxis; for example, a highly malignant family history carries greater justification than a large pedigree with only one sudden death.There is a need, however, for determining risk more accurately in those individuals with only one conventional risk factor. Programmed stimulation has been studied for its predictive value in primary prevention. 'Aggressive' protocols have been used and the most commonly induced arrhythmia is polymorphic ventricular tachycardia. These findings, however, are non-specific and of limited prognostic value. In addition the patients studied have been from selected high-risk populations without a low-risk cohort for comparison. Thus invasive EP studies appear to carry little advantage over non-invasive risk stratification. This is not surprising given that the mechanisms of cardiac arrest in HCM can be varied and may be modified by abnormal vascular responses and ischaemia. The relevance of invasively induced arrhythmias may therefore be limited.Other uses for electrophysiological study include the investigation and treatment of individuals with conduction disease and/or Wolff-Parkinson-White syndrome, atrial flutter and fibrillation and monomorphic ventricular tachycardia. Appropriate management may then involve radiofrequency ablation. A permanent pacemaker will be required if the atrio-ventricular node is ablated.     

Genetic basis of hypertrophic cardiomyopathy: from bench to the clinics

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder that characterized by marked thickening of the left ventricular wall that occurs in the absence of increased external load. HCM is the most common cause of sudden cardiac death under 35 years and in addition causes heart failure. HCM is usually inherited as an autosomal dominant mutation in genes that encode protein constituents of the sarcomere. To date, more than 450 different mutations have been identified within 13 myofilament-related genes. This review focuses current research involved in the discovery of other causative genes, investigation of the mechanisms by which sarcomere genes mutations produce hypertrophy and arrhythmia, and identification of modifying factors that influence clinical expression in HCM patients. The clinical implications of molecular advances in HCM are discussed.     

Sudden death in young athletes: HCM or ARVC?

Sudden non-traumatic death in young athletes is due to underlying congenital/inherited cardiac diseases in over 80% of cases. The two commonest conditions leading to sudden cardiac death in athletes below the age of 25 years are hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC).Hypertrophic cardiomyopathy is caused by mutations in genes, which code for sarcomeric contractile proteins. It can present with symptoms such as palpitation, presyncope or syncope. In a small number of cases, sudden death is the first clinical manifestation of the condition. It is well established that HCM accounts for over half of all cases sudden cardiac death in young individuals below 25 years of age. The management of HCM broadly encompasses symptom control, familial evaluation and the prevention of sudden death.Arrhythmogenic right ventricular cardiomyopathy, similarly, is a genetic disorder of the heart muscle and leads to symptoms such as palpitation and syncope and more rarely sudden death. The diagnosis of ARVC is most likely underestimated due to the lack of a single diagnostic test and subtle morphological changes in some cases. The diagnosis is based on clinical and family history and non-invasive investigations.The physiological adaptations seen in some athletes, as a response to physical training, may resemble phenotypically mild forms HCM and ARVC. Therefore, a diagnostic algorithm enabling this differentiation would be of importance especially bearing in mind the consequences of a misdiagnosis.     

Apical hypertrophic cardiomyopathy with left ventricular apical aneurysm: Importance of multi‐modality imaging

Apical hypertrophic cardiomyopathy (HCM) is an uncommon variant of HCM characterized by apical hypertrophy without the septal predominance seen in the majority of HCM cases. In 2% of patients, a concomitant left ventricular apical aneurysm is observed, which increases the risk of sudden death and adverse HCM‐related events. Multimodality imaging is helpful for appropriate identification of this particular morphologic pattern. Herein, we present a case of apical HCM with a left ventricular apical aneurysm, exemplifying the utility of a multimodality approach from resting electrocardiogram, transthoracic echocardiogram, left ventriculography, and cardiac magnetic resonance imaging, for proper risk stratification and treatment planning.     

Sudden cardiac death in familial hypertrophic cardiomyopathy. Identification of high-risk patients

Hypertrophic cardiomyopathy (HCM) is a relatively frequent, genetically determined primary cardiomyopathy, characterized by most often asymmetric hypertrophy of the ventricular septum with or without systolic obstruction of the left ventricular outflow tract. HCM is a genetically heterogeneous disease, with 12 different disease-causing genes beeing indentified to date. Histologically the disease is characterized by hypertophy and disarray of myofibrils as well as by an increase in myocardial fibrosis. Clinically, these changes may lead to palpitations, dyspnoe on exertion, and/or angina pectoris. However, they also lead to an increased propensity to the development of severe ventricular tachyarrhythmias and sudden cardiac death. The incidence of sudden death is significantly increased in HCM, particularly in affected young subjects. Risk stratification in HCM should include a complete clinical-cardiological evaluation that should also consider new diagnostic features, e. g. MR imaging. Major risk factors for sudden cardiac death include a survived cardiac arrest (ventricular fibrillation), non-sustained and sustained ventricular tachycardia, a history of premature familial sudden death, unexplained syncope, an abnormal blood pressure response on exercise, and left ventricular thickness greater than or equal to 3 cm. Ideally, risk stratification should also include genetic testing, since some gene mutations seem to be associated with a higher risk for sudden cardiac death than others. However, genetic testing in HCM in not yet available on a routine basis. The implantation of a cardioverter/defibrillator is first-line therapy in patients with documented ventricular tachycardia/fibrillation or patients who have survived sudden cardiac death. These devices also play an important role in the primary prevention of sudden cardiac death in HCM. Algorithms and scores are available to estimate the risk of sudden death, however, the decision to implant a cardioverter/defibrillator remains an individual decision in every single patient.     

恶性室性心律失常埋藏式心脏复律除颤器与药物治疗的对比研究

观察埋藏式心脏复律除颤器 (ICD)与药物对恶性室性心律失常的治疗效果 ,探讨其对心源性猝死的预防。94例患者 ,均有室性心动过速 (简称室速 )和 /或心室颤动等恶性室性心律失常发作史 ,其中冠心病 68例、原发性扩张型心肌病 2 6例。根据电生理心室程序刺激结果将患者分为药物治疗组 (A组 )、ICD组 (B组 )和慢频率室速药物治疗组 (C组 )。分别给予胺碘酮和 /或阿替洛尔药物治疗和ICD治疗。观察随访 1 ,2 ,5年的总生存率 ,不同左室射血分数 (EF)值亚组的生存率和心律失常性死亡的发生率。结果显示 ,随访 5年的总生存率C组明显低于A、B两组(P <0 .0 5 ) ,B组的低EF(≤ 0 .40 )值亚组的 5年生存率明显高于A、C两组的低EF值亚组 (P <0 .0 5 )。B组随访期间无心律失常死亡者 ,其心律失常性死亡事件的发生率明显低于A、C两组 (P <0 .0 5 )。结论 :ICD对于合并有恶性室性心律失常的心脏病人预防猝死的总体效果优于 β 阻断剂和胺碘酮等药物治疗。这尤其见于长期随访 (≥ 5年 )和伴有心功能不全 (EF值≤ 0 .40 )的病人。对于有过恶性室性心律失常发作史的患者 ,若心电生理检查不能诱发室速 ,在没有条件安装ICD时 ,胺碘酮与 β 阻断剂联合应用仍可在一定程度上减少心源性猝死的发生。     

QT-interval abnormalities in hypertrophic cardiomyopathy.

To examine whether QTc and QTc dispersion across the leads of a surface electrocardiogram (ECG) are different in patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, we measured QT and calculated QTc in all 12 leads of a surface ECG in 24 patients with HCM and in 20 age- and sex-matched normal control subjects. Maximal QTc was prolonged in HCM patients (465 +/- 24 ms) compared with controls (410 +/- 20 ms) (p < 0.001). QTc dispersion defined as the difference of maximum-minimum QTc was also greater in HCM patients (71 +/- 21 ms) compared with normals (35 +/- 11 ms) (p < 0.001). A correlation was found between the degree of left ventricular hypertrophy expressed by the maximal wall thickness and maximal QTc (r = 0.48, p < 0.02). However, QTc dispersion did not correlate with maximal wall thickness. Thus, patients with HCM show a prolonged QTc (> 440 ms) and increased QTc dispersion compared with normal subjects. In addition, the degree of left ventricular hypertrophy correlates with maximal QTc. The presence of a prolonged QT with increased regional dispersion may be associated with the occurrence of serious ventricular arrhythmia and sudden death in HCM.     

Successful Catheter Ablation of Hemodynamically Unstable Monomorphic Ventricular Tachycardia in a Patient with Hypertrophic Cardiomyopathy and Apical Aneurysm

Patients with hypertrophic cardiomyopathy (HCM) and left ventricular (LV) apical aneurysm represent a previously under-recognized but important subgroup within this heterogeneous disease spectrum. Apical aneurysms and the contiguous areas of myocardial fibrosis have been associated with monomorphic ventricular tachycardia (VT) and increased risk for adverse clinical events including sudden cardiac death, prioritizing the application of primary prevention implantable defibrillators. However, VT may be repetitive, thereby raising considerations for additional treatment strategies such as radiofrequency ablation. In this report, we describe such a patient with HCM and apical aneurysm in whom the mapping and ablation procedure was effective in identifying and abolishing the VT focus.     

Effects of amiodarone on erect and supine exercise haemodynamics and exercise capacity in patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a primary heart muscle disease associated with a high incidence of sudden death. Amiodarone is of benefit in those patients with a high risk profile for sudden death. Amiodarone has also been reported to improve symptoms dramatically in some patients with HCM but to cause functional deterioration in others. In the acute phase of oral amiodarone therapy there are few discernable changes in cardiovascular haemodynamics and the mechanisms of any beneficial effects on symptoms remain unclear. To determine the effect of amiodarone on exercise responses we measured haemodynamic indices in 10 patients during maximal supine- and symptom-limited erect treadmill exercise before and 6 weeks after amiodarone therapy. Following amiodarone therapy there was a significant reduction in resting and peak heart rate during erect exercise (76 +/- 13 vs 97 +/- 19 b.min-1; P = 0.001 and 114 +/- 26 vs 146 +/- 21 b.min-1; P = 0.001 respectively). Despite increases in peak pulmonary and systemic artery pressures with amiodarone therapy there was no difference in the peak left ventricular filling pressure or maximum cardiac output achieved. Similarly, during supine exercise the resting and peak heart rates were less following the 6 weeks amiodarone therapy. Comparison of supine and erect exercise haemodynamic indices demonstrated higher peak LV filling and higher peak systolic and pulmonary artery pressures during supine than during erect exercise (29 +/- 10 vs 25 +/- 12; P less than 0.04; 151 +/- 42 vs 126 +/- 48; P = 0.01 and 66 +/- 27 vs 62 +/- 21; P = 0.08 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)