心脏磁共振在肥厚型心肌病诊治中的应用进展

肥厚型心肌病是最常见的遗传性心脏病,可导致患者发生心源性猝死、心力衰竭等严重心血管事件。因此,准确的诊断与危险分层对于临床诊疗至关重要。心脏磁共振可以无创评估患者的心脏结构、功能以及组织特征,在肥厚型心肌病的鉴别诊断以及预后判断中均可发挥重要价值。包括特征追踪、弥散张量成像以及4D flow在内的磁共振新技术也在临床中得到初步应用,有望在肥厚型心肌病发生发展机制研究以及早期诊断中发挥重要作用。     

高危肥厚型心肌病患者的治疗策略

肥厚型心肌病是以不能解释的左心室肥大为特征、具有常染色体显性遗传特性的心肌疾病。梗阻性肥厚型心肌病患者因左室流出道存在梗阻,故症状明显,且更易出现恶性心律失常或心脏性猝死等严重事件,且尚无理想的治疗措施,目前以药物治疗、室间隔心肌酒精消融术、外科手术为主。现就心率慢而不能耐受药物治疗、具有心脏性猝死家族史且伴有晕厥、恶性心律失常的高危肥厚型心肌病患者的治疗做一综述。     

梗阻性肥厚型心肌病的治疗进展

肥厚型心肌病是指并非完全因心脏负荷异常引起的左心室室壁增厚,是常见的常染色体显性遗传病。梗阻性肥厚型心肌病患者临床症状重,恶性心律失常和心脏性猝死风险高,现就此疾病近年的治疗进展做一综述。     

肥厚型心肌病患者埋藏式心脏自动复律除颤器(ICD)植入后的长期生存率和风险

肥厚型心肌病是最常见的一种心肌病,而心脏性猝死是肥厚型心肌病患者的首位死因。埋藏式心脏自动复律除颤器（ICD）作为一种最有效的治疗手段被推荐用于改善猝死高危患者的长期生存率。但是,尽管埋藏式心脏自动复律除颤器在肥厚型心肌病患者猝死预防方面起到了不可否定的作用,但术后不良事件及进展性心力衰竭的风险居高不下,导致了部分植入ICD的患者预后改善不理想,引人深思,笔者就次做一综述。     

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...     

肥厚型心肌病室性心动过速射频导管消融及随访4例报道

肥厚型心肌病伴室性心动过速是心脏性猝死的高危因素,虽然射频导管消融（下称消融）治疗特发性室性心动过速已取得很大成功,对于病理性室性心动过速,如心肌梗死后室性心动过速的报道也逐渐增多,但肥厚型心肌病伴室性心动过速的消融仅有小样本报道。本文报道4例肥厚型心肌病并单形性室性心动过速患者的消融及中长期随访结果。     

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。     

心肌纤维化和肥厚型心肌病研究进展

肥厚型心肌病是最常见的遗传性心肌病,被认为是青少年和运动员心源性猝死的首要原因,而纤维化在该疾病的发生发展中起着重要的作用。轧延迟增强扫描技术的出现对于肥厚型心肌病的诊断、鉴别诊断及危险分层有很大价值。现将心肌纤维化及肥厚型心肌病的研究做一综述。     

起搏治疗肥厚梗阻性心肌病的疗效观察

肥厚型心肌病是一种具有明显遗传倾向的心肌病,其中有左心室流出道梗阻者称为肥厚璎梗阻性心肌病.肥厚型梗阻性心肌病是严重威胁人类身体健康和造成心脏性猝死的心血管疾病之一.晕厥及猝死可以为该病的首发症状.预后不佳.药物治疗不能完全缓解症状.     

Outcomes and Revascularization Strategies of ST-Elevation Myocardial Infarction in Patients With Hypertrophic Cardiomyopathy

Myocardial ischemia is a known complication of HCM. Contemporary outcomes and care processes after STEMI are extensively examined; however, there are limited data on outcomes, and revascularization strategies of HCM patients with STEMI. The National Inpatient Sample 2004-2018 was queried to identify adult patients presenting with a primary diagnosis of STEMI, of whom a subset of patients with concomitant diagnosis of HCM were identified. Complex samples multivariable logistic and linear regression models were used to determine the association of HCM with in-hospital outcomes. HCM patients with STEMI who were revascularized were compared with their counterparts who were not revascularized. Of 3,049,068 primary STEMI hospitalizations, 2583 (0.8%) had an associated diagnosis of HCM. HCM patients were more likely to be elderly and female with less traditional cardiovascular risk factors compared to those without HCM. HCM patients were less likely to receive revascularization compared to those without HCM. STEMI with HCM was associated with similar in-hospital mortality (adjusted odds ratio [aOR] 1.09; 95% confidence interval [CI] 0.82-1.44; P = 0.561) compared to those without HCM. Notably, HCM patients who were revascularized had similar in-hospital mortality (aOR 0.69; 95% CI 0.36-1.33; P = 0.266) compared to HCM patients who did not receive revascularization. Despite lower rates of revascularization, STEMI in patients with HCM is associated with similar in-hospital mortality compared to those without HCM.     

Can serum carnitine levels distinguish hypertrophic cardiomyopathy from hypertensive hearts?

Although echocardiography is a useful diagnostic tool in hypertrophic cardiomyopathy (HCM), it is sometimes difficult to differentiate it from hypertensive heart disease (HHD): some patients with HCM show symmetrical hypertrophy, whereas patients with HHD sometimes show asymmetrical septal hypertrophy. We used a radioiodinated long-chain fatty acid tracer to visualize the altered myocardial fatty acid metabolism of HCM and HHD. Carnitine is the essential substance for the beta-oxidation of long-chain fatty acids. We recently reported that serum free carnitine levels in HCM were elevated and that they were significantly correlated with the severity of myocardial fatty acid metabolic disorder. Therefore, we investigated serum carnitine levels in patients with HCM and HHD, which can contribute to the differentiation of each other. We studied 56 patients with HCM and 20 patients with essential hypertension. Serum free carnitine levels were significantly higher in patients with HCM than those with HHD (HCM 52.5+/-9.5 nmol/mL, HHD 46.6+/-6.4 nmol/mL, P<0.01), but they showed no statistical difference between patients with HHD and normal subjects. Serum acylcarnitine levels were significantly lower in patients with HCM than those with HHD (HCM 10.1+/-4.0 nmol/mL, HHD 14.5+/-4.9 nmol/mL, P<0.0005), although they did not differ between patients with HHD and normal subjects. Scintigraphic analyses with a long-chain fatty acid analog revealed that myocardial tracer uptake was much reduced in patients with HCM compared with that in patients with HHD (quantitative analysis: HCM 2.11+/-0.12, HHD 2.22+/-0.17, P<0.05; semiquantitative analysis: HCM 13.6+/-6.3, HHD 2.0+/-1.5, P<0.0001). In conclusion, the differences in serum carnitine levels between HCM and HHD reflect altered myocardial fatty acid metabolic impairment, and the levels can help to distinguish these 2 diseases.     

CD36 deficiency has little influence on the pathophysiology of hypertrophic cardiomyopathy.

CD36 is homologous with myocardial long-chain fatty acid (LCFA) binding protein and has been suggested to relate to myocardial fatty acid metabolism. Myocardial scintigraphy with iodine-123 15-(p-iodophenyl)-3-(R, S)-methylpentadecanoic acid (BMIPP) revealed an impairment in LCFA metabolism chiefly in the hypertrophic myocardium in hypertrophic cardiomyopathy (HCM). Recently, the incidence of CD36 deficiency has been reported to be high in HCM patients, and CD36 deficiency was proposed as an etiology of hereditary HCM. However, the pathophysiological effect of CD36 deficiency on HCM has not been fully investigated. We analysed the expression of CD36 antigens on both platelets and monocytes obtained from 82 patients with HCM using two-color flow cytometry. Among the study patients, seven patients (8.5%) demonstrated type II CD36 deficiency, whereas type I CD36 deficiency was not detected. Two of 23 patients (8.7%) with a family history of HCM and five of 59 patients (8.5%) without a family history of HCM showed type II CD36 deficiency respectively. Contrary to the previous report, three of 53 patients with asymmetric septal hypertrophy (ASH) (5.7%) and four of 29 patients without ASH (13.8%) showed CD36 deficiency. Moreover, clinical characteristics, scintigraphic findings, echocardiographic data, and hemodynamic findings disclosed no significant differences between the HCM patients showing normal CD36 expression and those with CD36 deficiency. The incidence of CD36 deficiency in HCM patients is not higher than in the general population. Therefore, CD36 deficiency is not a characteristic factor of HCM and has little influence on the pathyphysiology of HCM.     

Advances in hypertrophic cardiomyopathy: What the cardiologist needs to know

Hypertrophic cardiomyopathy (HCM) is known as the most common genetic heart disease, characterized by otherwise unexplained left ventricular (LV) hypertrophy. In spite of major advances in whole genome sequence techniques, it is still not possible to identify the causal mutation in approximately half of HCM patients. Consequently, a new HCM concept, “beyond the sarcomere” is being developed, supported by data from recent HCM registries which reveal two distinct HCM subgroups: sarcomere positive HCM subgroup and nonfamilial HCM subgroup. Sarcomere positive HCM patients tend to be younger age at diagnosis, have fewer co-morbidities, present more often with reverse septal morphology, more myocardial fibrosis, less LV outflow tract obstruction, and a worse prognosis when compared to nonfamilial HCM patients. These subgroups, with different molecular basis, phenotypes and clinical profiles, will likely require specific management strategies.Important research advances have also been made concerning diagnosis, sudden cardiac death stratification and therapy. In this article, we seek to review recent relevant knowledge, summarizing the advances in this complex and heterogeneous disease.     

Hypertrophic cardiomyopathy with left ventricular dilatation

There is increasing interest in the notion that some patients with hypertrophic cardiomyopathy (HCM) progress to morphological and functional manifestations similar to those of dilated cardiomyopathy (DCM). From 165 consecutive patients with HCM, 20 patients with left ventricular dilatation (left ventricular end-diastolic diameter greater than or equal to 50 mm) were selected and designated as dilated HCM. The diagnosis of HCM was established in these patients either by detection of the classical form of HCM in family members, with 2-dimensional echocardiographic evidence of asymmetric septal hypertrophy (ASH; septal thickness greater than or equal to 15 mm and a ratio of septal to posterior wall thickness greater than or equal to 1.3); or by demonstrating myocardial fiber disarray in autopsy or biopsy samples. The clinical manifestations of these patients with dilated HCM were then compared with those of other forms of HCM without left ventricular dilatation; 1) 40 patients with hypertrophic obstructive cardiomyopathy (HOCM) who had resting intraventricular pressure gradients of 20 mmHg or more, 2) 80 patients with non-obstructive HCM, each of whom had ASH of the entire ventricular septum (typical ASH), and 3) 25 non-obstructive patients whose hypertrophy was localized to the apical region of the ventricular septum (apical ASH). Patients having apical hypertrophy with a spade-like configuration on the left ventriculogram were excluded from the study. Compared with HOCM and typical ASH groups, the patients with dilated HCM had family histories of significantly more frequent HCM and less frequent hypertension. The patients with dilated HCM also had significantly less fractional shortening (FS), decreased interventricular septal thickness, greater left ventricular end-diastolic pressure (LVEDP), and left ventricular dilatation. During the follow-up period (average: 3.5 years), seven patients (35%) with dilated HCM died; five from congestive heart failure (CHF), one suddenly, and one three days following mitral valve replacement. The other five patients had CHF at the time of their follow-up examination. The patients with apical ASH had clinical features similar to those of dilated HCM; a higher familial frequency, less marked septal hypertrophy, and higher LVEDP. They tended to develop left ventricular dilatation, associated with reduced fractional shortening, although left ventricular diameter at end-diastole did not exceed 50 mm. These findings suggested that dilated HCM is not a rare condition. It is observed in 12% of consecutive patients with HCM.(ABSTRACT TRUNCATED AT 400 WORDS)     

Abnormal QT interval variability in patients with hypertrophic cardiomyopathy: can syncope be predicted?

We sought to determine QT variability pattern in patients with hypertrophic cardiomyopathy (HCM) and its relationship with the risk of syncope. QT interval variability was assessed from 24-hour Holter monitoring in 10 HCM patients with history of syncope, 10 HCM patients without history of syncope, and 10 healthy subjects. QT variability was higher in patients with HCM, in particular in those with history of syncope, than in healthy controls. Time domain QT variability did not vary between waking and sleeping hours in HCM patients, whereas it was significantly shorter while asleep in the control group. Increased QT SDANN identified HCM patients with history of syncope with an accuracy of 75%. Our data show that QT variability is abnormal in HCM patients and indirectly support the concept that arrhythmia-related syncope in these patients may be, at least in part, related to an altered control of repolarization.     

Hypertrophic Cardiomyopathy: Current Treatment and Future Options

Hypertrophic cardiomyopathy (HCM) is a disease involving the cardiac sarcomere. It is associated with various disease-causing gene mutations and phenotypic expressions, managed with different therapies with variable prognoses. The heterogeneity of the disease is evident in the fact that it burdens patients of all ages. HCM is the most prevalent cause of sudden death in athletes. However, several technological advancements and therapeutic options have reduced mortality in patients with HCM to 0.5% per year. In addition, rapid advances in our knowledge of the molecular defects accountable for HCM have strengthened our awareness of the disorder and recommended new approaches to the assessment of prognosis. Despite all these evolutions, a small subgroup of patients with HCM will experience sudden cardiac death, and risk stratification remains a critical challenge. This review provides a practical guide to the updated recommendations for patients with HCM, including clinical updates for diagnosis, family screening, clinical imaging, risk stratification, and management.     

Transthyretin amyloidosis: a phenocopy of hypertrophic cardiomyopathy

Objectives: Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disorder that affects over one in 500 persons worldwide. The autosomal dominant transmission of HCM implies that many relatives are at risk for HCM associated morbidity and mortality, therefore genetic testing and counselling is of great importance. However, in only 50–60% of the patients a mutation is found, which hampers predictive genetic testing in relatives. In HCM patients in whom the causal mutation has not been identified (yet), phenocopies of HCM – i.e. diseases that mimic HCM – could be responsible for the HCM phenotype. One of the HCM phenocopies is transthyretin amyloidosis (ATTR), caused by mutations in the transthyretin (TTR) gene.

Methods: From 697 HCM index patients referred to our cardiogenetics outpatient clinic and tested for HCM associated genes between January 1997 and December 2012, we selected the ones without a detected causal mutation (n?=?345). In these patients, additional DNA analysis of the TTR gene was performed.

Results: In four patients (1.2%), a TTR mutation was detected (E7G, V30M, T119M, V122I). The E7G mutation is probably a non-pathogenic mutation. The T119M mutation is a known TTR mutation, but does not cause a cardiac phenotype. So in two (0.6%) patients, TTR analysis identified the cause of their HCM.

Conclusions: ATTR should always be considered in patients with unexplained HCM, especially because of the great benefit of an early diagnosis regarding treatment and prognosis.     

Comparison of diastolic septal perforator flow velocities in hypertrophic cardiomyopathy versus hypertensive left ventricular hypertrophy

In this study, we measured diastolic septal perforator flow velocities by Doppler transthoracic echocardiography (TTE) in patients with hypertrophic cardiomyopathy (HCM). Using color-guided pulsed Doppler TTE, septal perforator flow velocity recordings were attempted in 69 patients and successfully recorded in 47 (68%). First, we compared 14 patients with HCM to 12 controls and to 11 patients with hypertension with left ventricular hypertrophy. Next, in 10 additional patients with HCM, we compared the septal velocities with the epicardial left anterior descending artery (LAD) velocities recorded during the same TTE study. In the patients with HCM, the peak septal diastolic velocities were twice that of the normal controls (88 +/- 40 vs 41 +/- 13 cm/s) and also higher than in hypertensive left ventricular hypertrophy (51 +/- 18 cm/s, p < 0.0001). All 10 patients with HCM showed a step-up of peak diastolic velocity from the LAD to the septal perforator from 41 +/- 9 to 72 +/- 17 cm/s (p < 0.0001). Three patients with HCM had surgical septal myectomy. These patients had luminal narrowings of the small intramural arteries at histopathologic examination. In conclusion, pulsed Doppler measurement of septal perforator flow velocities is feasible. In HCM, the epicardial coronary arteries enlarge to accommodate increased flow, and diastolic velocity is normalized. In contrast, the increased velocities in the septal branches of patients with HCM are similar to those previously observed in tunnel-like obstructions. These findings suggest that in HCM, notwithstanding an increase in coronary flow, hemodynamically significant narrowings are present in the septal branches. Doppler TTE may become useful for evaluation of abnormal intramural coronary flow in HCM.