MYH7基因突变致儿童肥厚型心肌病的研究进展北大核心CSCD

肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是儿童中最常见的单基因遗传性心肌病。肌节基因[β-肌球蛋白重链(cardiac beta-myosin heavy chain,MYH7)、MYBPC3等基因]突变是HCM最常见的遗传学病因,其中以MYH7基因突变最常见,占30%~50%。MYH7基因突变具有受环境因素影响、可合并多个基因变异,以及年龄依赖的外显率等特点,使患儿临床表型不一或重叠,包括多种心肌病和骨骼肌疾病。目前关于MYH7基因突变导致儿童HCM的发病机制、病程及预后尚不明确。该文通过总结MYH7基因突变导致HCM可能的发病机制、临床表型及治疗,以期有利于患儿的精准预后评估、个体化管理及治疗。     

Clinical outcomes of catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular cardiomyopathy: Insights from the Johns Hopkins ARVC Program

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Strain and Strain Rate Imaging in Cardiomyopathy

The most common indication for an echocardiogram is for the assessment of left ventricular (LV) function and, in the evaluation of cardiomyopathy (CM), this becomes even more important. However, conventional echocardiographic measures of ventricular function are insensitive at detecting subtle perturbations in contractility. In patients with CM, the ability to detect abnormalities early in the course of the disease to establish a diagnosis can be critical and often may influence specific treatments administered as well as establish important prognostic information. Technologic advances in echocardiographic imaging during the last decade now allow for the measurement of LV strain and strain rate (SR) imaging. Strain and SR imaging allow for a more precise characterization of the mechanics of myocardial contraction and relaxation (deformation imaging) and emerging data are establishing the use of these techniques in a variety of different cardiomyopathic conditions. After establishing a common understanding of strain imaging as well as defining the methods by which these measures can be incorporated into an echocardiographic examination, we will review the accumulating information illustrating the great promise that this imaging modality has in the care of patients with CM. This review will focus on the role of strain and SR imaging in CM.     

Polyarteritis nodosa and hypertrophic obstructive cardiomyopathy. A true association?

A 60-year-old man with polyarteritis nodosa under treatment presented with syncope. Echocardiography demonstrated hypertrophic obstructive cardiomyopathy; coronary arteriography revealed normal findings, and Holter monitor showed episodes of non-sustained ventricular tachycardia. This is the first report of hypertrophic obstructive cardiomyopathy developing in a patient with polyarteritis nodosa. Further studies should examine whether a true association exists.Abbreviations ESR Erythrocyte sedimentation rate - PAN Polyarteritis nodosa     

Monoclonal gammopathy of undetermined significance in systemic transthyretin amyloidosis (ATTR)

Objective: To identify the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in patients with transthyretin (ATTR) amyloidosis.

Patients and methods: We performed a retrospective analysis of patients with biopsy-proven ATTRwt (wild-type transthyretin amyloid protein) and genopositive ATTR V122I (valine-to-isoleucine substitution at position 122 of the TTR gene) amyloidosis evaluated at the Amyloidosis Center at Boston University and Boston Medical Center between 1 January 2003 and 31 December 2016.

Results: There were a total of 226 patients with ATTRwt and ATTR V122I amyloidosis evaluated during the specified time frame with 155 and 71 patients in each cohort, respectively. Those with complete medical records, 140 patients with ATTRwt and 57 V1221 ATTRm subjects, were included in the analyses. Fifty-five patients (39%) in the ATTRwt cohort and 28 patients (49%) in the ATTR V122I cohort had an MGUS, as indicated by an abnormality in the serum-free light-chain ratio and/or serum immunofixation electrophoresis.

Conclusion: These data confirm the high prevalence of coexistent MGUS with ATTR amyloidosis in this patient population, with an MGUS rate that is higher than the general population. These findings also highlight the importance of a thorough diagnostic evaluation in patients with amyloidosis to determine the precursor protein, as the clinical course and treatment of AL (light-chain amyloid protein) and ATTR amyloidosis are distinct.     

Dilated versus nondilated cardiomyopathy in the elderly population treated with guideline-based medical therapy for systolic chronic heart failure

BACKGROUND: Although the process by which the left ventricular (LV) remodels in response to an injury generally leads to dilatation, in patients with heart failure (HF) the recognition of a small or mildly dilated left ventricle is not uncommon. We investigated the prevalence and the characteristics of elderly patients with traditional dilated and nondilated cardiomyopathy (CMP). We also assessed the response to the guideline-based medical therapy and the prognosis based on LV dilatation in this population. METHODS AND RESULTS: We selected 243 patients >70 years of age with HF and LV ejection fraction <40% who underwent clinical and echocardiographic evaluations at baseline and after 12 months. They were subdivided into 2 groups according to baseline LV end-diastolic volume (LVEDV) (values < or =78 mL/m(2) identified nondilated CMP). Nondilated CMP was recognized in 64 patients (26%) who showed at baseline better clinical status, less severe mitral regurgitation, and higher LV ejection fraction than those with dilated CMP. At the final evaluation, favorable changes in clinical and echocardiographic parameters could be detected in both groups. The magnitude of these variations did not differ between the groups. The risk of hospitalization for worsening HF was 2.4-fold higher in patients with nondilated than dilated CMP. Mortality was 11% and 20%, respectively (P = .06). Statistical analysis revealed a direct, approximately linear relationship between LVEDV and outcomes in this population. CONCLUSIONS: A total of 1 of 4 elderly patients with systolic HF had a nondilated left ventricle. These patients had a better clinical presentation than did counterparts with dilated left ventricles. After HF therapy is optimized, the likelihood of improvement is independent of LV size in this population, whereas the risk of death or worsening HF linearly increases with LV dilatation.     

胎儿心肌致密化不全的超声心动图诊断与病理对比研究

目的：研究胎儿心肌致密化不全心肌病(ventricular non-compaction cardiomyopathy,NCCM)的产前超声心 动图诊断及其病理特征和心肌超微结构的特点。方法：2004年到2013年产前超声诊断9例胎儿NCCM,观察其产前超 声心动图表现,与产后超声心动图或尸体解剖进行对比,并取心肌组织进行病理检查,观察NCCM心肌超微结构特 点。结果：NCCM心肌的超声心动图表现为异常粗大的肌小梁、肌小梁隐窝和心肌非致密层厚度/致密层厚度≥2。 产前超声心动图诊断9例胎儿NCCM中,6例累及左心室,2例累及双心室,1例累及右心室。其中2例胎儿继续妊娠至 分娩,并经产后超声心动图证实,其他7例均选择终止妊娠并经尸体解剖病理证实,心肌组织活检显示NCCM心肌的 线粒体和肌小节发育不良、心肌纤维化。结论：通过产前超声心动图诊断NCCM是可行的。胎儿NCCM可以累及左 心室、右心室或两个心室。NCCM心肌的线粒体和肌小节成熟度低并伴有心肌纤维化。     

Clinical significance of left atrial geometry in dilated cardiomyopathy patients: A cardiovascular magnetic resonance study

BackgroundClinical significance of left atrial (LA) function and geometry in patients with dilated cardiomyopathy (DCM) remains uncertain.HypothesisLA geometric parameters assessed by cardiac magnetic resonance (CMR) predict the prognosis in patients with DCM.MethodsThe present study included patients with DCM and sinus rhythm who underwent CMR between December 2007 and April 2018. LA volume was measured using CMR. LA sphericity index was computed as the ratio of the measured maximum LA volume by the volume of a sphere with maximum LA length diameter.ResultsWe included 255 patients in this study. During the mean follow‐up of 3.92 years, hospitalization for HF occurred in 37 patients. The LA sphericity index was significantly higher in patients with hospitalization for HF than in those without (0.78 ± 0.35 vs. 0.58 ± 0.18, p < .001). Multivariable Cox regression analysis identified a higher LA sphericity index as an independent predictor of hospitalization for HF. Patients were categorized based on the median of LA sphericity index. The Kaplan–Meier curve showed that patients with a high LA sphericity index (≥0.57) had a significantly higher risk of hospitalization for HF than those with a low LA sphericity index (<0.57).ConclusionLA sphericity index was an independent predictor of hospitalization for HF. Assessment of LA geometric parameters might be useful for risk stratification in patients with DCM.