肥厚型心肌病心电图碎裂QRS波与磁共振扫描心肌延迟增强相关性分析

目的探讨肥厚型心肌病（hypertrophiccardiomyopathy,HCM）患者心电图出现碎裂QRS波（fragmentedQRs,fQRS）与心脏磁共振扫描（cardiacmagneticresonance,CMR）心肌延迟增强的相关性。方法HCM患者141例,均行CMR及心电图检查,记录患者一般情况、家族史、超声心动图指标、心电图指标、CMR是否检出心肌延迟增强及部位,分析心电图fQRS与CMR检出心肌延迟增强的相关性。结果141例心电图出现病理性Q波9例（6．4％）,余132例心电图出现fQRS者52例（fQRs组）、未出现fQRS者80例（无fQRS组）;fQRS组最大室壁厚度、E／A比值及HCM家族史、家族猝死史、伴束支阻滞、CMR检出心肌延迟增强比例与无fQRS组比较差异均有统计学意义（P〈0．05）;HCM家族史、心电图伴束支传导阻滞及CMR检出心肌延迟增强是HCM患者心电图出现fQRS的独立危险因素。结论HCM患者心电图fQRS与CMR检出心肌延迟增强相关,HCM患者心电图出现fQRS可能与早期心肌纤维化有关。     

心脏磁共振在肥厚型心肌病预后评估及危险分层中的应用进展

肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是最常见的遗传性原发型心肌病,也是青年人猝死的最常见原因.心脏磁共振(cardiovascular magnetic resonance,CMR)多参数、多模态成像,能从多个方面综合评估患者心脏受累程度,从而为HCM患者危险分层及预后评估提供...     

心脏磁共振影像组学对肥厚性心肌病的诊断和预测价值

<正>肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是临床常见的慢性和危及生命的遗传性心肌病^[1]。目前认为HCM的患病率至少为1/200^[2],通过临床症状、心电图、心脏超声、心脏磁共振(cardiac magnetic resonance,CMR)、心肌活检或基因检测等检查来综合诊断^[3]。CMR成像由于其无创性和多功能性在评估心脏结构和功能方面被广泛接受^[4],但CMR无法区分HCM和高血压性心脏病,或扩张性心肌病和运动员心脏重塑^[5]。因此,需要一些技术手段来提高CMR的诊断准确性和预测能力。影像组学是一种新的图像分析技术,     

心脏磁共振影像组学对肥厚型心肌病的价值研究

目的 初步探索基于心脏磁共振（cardiovascular magnetic resonance, CMR）影像组学揭示肥厚型心肌病（hypertrophic cardiomyopathy, HCM）患者心肌病变影像组学特征的临床应用价值。材料与方法 回顾性分析宁夏医科大学总医院2018年1月1日至2022年12月31日确诊为HCM的患者142例及健康对照组72例的CMR影像及临床资料。选择CMR未增强亮血电影序列左心室长轴位两腔心、四腔心二尖瓣口水平切面,以舒张末期壁厚（end-diastolic wall thickness, EDWT）为基础,将HCM患者心肌分为肥厚区域（无HCM家族史,EDWT≥15 mm;有HCM家族史,EDWT≥13 mm）与非肥厚区域（无HCM家族史,EDWT<15 mm;有HCM家族史,EDWT<13 mm）,和健康对照组在室间隔、心尖、左心室侧壁、左心室前壁及左心室下壁等相同解剖部位室壁分别进行感兴趣区（region of interest, ROI）勾画及影像组学特征提取,分组后行影像组学特征组间比较。采用Mann-Whitney U检...     

CMR影像组学联合临床因素预测肥厚型心肌病并发室性心律失常的价值

目的 探讨基于心脏磁共振（cardiovascular magnetic resonance, CMR）不同区域心肌的影像组学特征及相关临床因素在预测肥厚型心肌病（hypertrophic cardiomyopathy, HCM）患者并发室性心律失常（ventricular arrhythmias, VAs）中的价值。材料与方法 回顾性分析宁夏医科大学总医院2018年1月1日至2023年5月31日的122例确诊HCM患者的CMR图像及临床资料。根据24 h动态心电图（24-hour dynamic electrocardiogram, 24 h DCG）结果将其分为合并VAs组（40例）与未合并VAs组（82例）。按照7∶3的比例将所有受试者分为训练集与测试集,训练集用于构建模型,测试集用于评估模型效能。选择从二尖瓣水平至心尖部的左心室短轴未增强亮血电影序列,以舒张末期壁厚为基础,将HCM患者心肌分为肥厚区域与非肥厚区域。在左心室短轴各层面心肌的心室舒张末期进行全室壁心肌、肥厚区域心肌及非肥厚区域心肌的感兴趣区勾画及影像组学特征提取。采用Mann-Whitney U检验、递归特征消除法...     

心脏磁共振和超声诊断肥厚性心肌病的价值

目的分析心脏磁共振(CMR)成像技术和超声心动图对肥厚性心肌病(HCM)的诊断,探讨两种方法诊断HCM的价值。方法 53例HCM患者均进行3.0 T CMR和超声心动图检查。CMR检查包括常规成像、灌注及延迟强化,测量心肌厚度,评价心肌延迟强化特点。超声心动图测量左室壁各节段心肌厚度,评价左室流出道梗阻程度。比较CMR和超声心动图评价心肌厚度及纤维化能力的差异。结果肥厚性心肌病CMR和超声心动图测量心肌各节段厚度除侧壁外,两种方法测量其余室壁心肌厚度值的差异无统计学意义。CMR表现为延迟强化39例,7例局限性强化,5例弥漫性强化,2例透壁性强化,异常强化灶分布在游离壁和室间隔交界区、室间隔。超声心动图显示44例患者有左室流出道梗阻。结论心脏超声在测量心脏除侧壁外其余节段厚度时不劣于CMR,而测量侧壁时存在一定误差,易高估侧壁厚度。CMR可用于心肌纤维化的定量检测。超声心动图可以实时显示二尖瓣收缩期前向运动,评价左室流出道梗阻程度优于CMR。     

深度学习及影像组学在肥厚型心肌病中的应用进展

肥厚型心肌病(HCM)是最常见的非缺血性心肌病之一。超声心动图(UCG)和心脏MR(CMR)等是诊断HCM的主要影像学方法，但分析HCM图像较为繁琐，且需要进行鉴别诊断，导致诊断难度增加。近年来，深度学习和影像组学在智能化诊断HCM、自动化处理图像、预测基因型及心肌纤维化等方面发挥重要作用。本文对深度学习和影像组学技术在HCM中的应用进展进行综述。     

放射性核素显像在心肌病诊治中的临床应用

心肌病是指伴有心肌功能障碍的心肌疾病。根据病理生理学可分为4型，即肥厚型心肌病（HCM）、扩张型心肌病（DCM）、限制性心肌病（RCM）以及致心律失常型右室心肌病（ARVD／C）。其中HCM与DCM在临床中较为常见。HCM的发病率大约为1／500^[1-2]，而DCM的发病率为13／10万～84／10万不等^[3]。目前HCM与DCM的发病病因及致病机理尚不确切明了。     

3.0T心脏磁共振对肥厚性心肌病心肌纤维化与心肌损伤标志物的关系研究

目的运用3.0 T心脏磁共振(CMR)延迟强化(LGE)技术对肥厚性心肌病(HCM)心肌纤维化进行定量检测,并获得LGE与心肌标志物即心肌代谢酶的关系,从而探究HCM患者心肌标志物升高是否与心肌纤维化造成的心肌细胞损伤有关。方法纳入34例HCM患者(HCM组)与20例健康志愿者(正常对照组)。两组均行3.0 T CMR扫描,包括短轴位心脏电影及LGE序列。心脏功能用短轴为心脏电影序列测定;运用LGE序列测定HCM与正常对照组的LGE参数,包括总LGE率、LGE体积及LGE质量;测定与心肌损伤程度有关的血清心肌标志物含量,包括肌酸激酶同工酶、肌钙蛋白。采用独立样本t检验及Pearson积矩相关对心肌标志物及LGE参数进行统计分析。结果 HCM组肌酸激酶同工酶、肌钙蛋白均大于临床正常范围。通过LGE检测,HCM组的LGE参数,包括总LGE率、LGE体积及LGE质量均大于正常对照组[分别为(18.95±9.87)%vs.(50.82±14.18)%、(8.50±4.50)ml vs.(86.26±41.99)ml及(9.00±4.80)g vs.(90.58±44.11)g,均P<0.05]。Pearson积矩相关证明,HCM组肌酸激酶同工酶与总LGE率、LGE体积呈正相关(r值分别为0.759、0.448,P值分别为0.000、0.008)。肌钙蛋白与总LGE率、LGE体积呈正相关(r值分别为0.647、0.578,P值均为0.000)。结论 3.0 T CMR LGE技术可用于肥厚性心肌病心肌纤维化的定量检测,HCM患者心肌标志物与心肌的LGE率呈正相关,表明心肌纤维化造成的心肌细胞损伤可能导致心肌细胞内的代谢酶类即心肌标志物释放,从而影响心肌的代谢功能,最终造成心脏功能损伤。     

磁共振心肌首过灌注成像评价肥厚型心肌病微循环功能障碍

目的 应用MR心肌首过灌注成像评价肥厚型心肌病患者局部心肌微循环障碍.方法 选取22例肥厚型心肌病患者(HCM组)和13名健康志愿者(对照组)行心脏MR (CMR)检查(包括左心室短轴电影、心肌首过灌注和延迟增强序列),测量左心室舒张末期各心肌节段心肌壁厚度、心肌信号强度最大上升斜率(Slopemax)和心肌延迟强化(DE).采用单因素方差分析比较对照组心肌节段、HCM组非肥厚性心肌节段亚组和肥厚性心肌节段亚组的Slopemaax以及不同肥厚程度心肌节段的SlopemaX,对有DE心肌节段和无DE心肌节段的Slopemax的差异采用独立样本t检验进行分析.结果 HCM组中非肥厚性心肌节段亚组和肥厚性心肌节段亚组Slopemax均明显低于对照组(P均<0.05),其中肥厚性心肌节段亚组的Slopemax较非肥厚性心肌节段亚组降低更为显著(P＜0.05);轻度肥厚心肌节段Sl0pemax高于中度、重度肥厚心肌节段(P均＜0.05),但中度与重度心肌肥厚节段Slopemax的差异无统计学意义(P＞0.05).DE心肌节段Slopemax明显低于无DE心肌节段(P＜0.05).结论 MR心肌首过灌注成像能可靠地检出HCM局部心肌的微血管功能障碍,为临床对HCM患者进行风险分层、制定治疗计划和预后评估提供有价值的信息.     

Late gadolinium enhancement cardiovascular magnetic resonance in genotyped hypertrophic cardiomyopathy with normal phenotype

A 35 year-old asymptomatic Caucasian female with a family history of hypertrophic cardiomyopathy (HCM) was referred for cardiologic evaluation. The electrocardiogram and transthoracic echocardiogram were normal. Cardiovascular magnetic resonance (CMR) was performed for further assessment of myocardial function and presence of myocardial scar. CMR showed normal left ventricular systolic size, measurements and function. However, there was extensive, diffuse late gadolinium enhancement (LGE) throughout the left ventricle. This finding was consistent with extensive myocardial scarring and was highly suggestive of advanced, non-ischemic cardiomyopathy. Genotyping showed a heterozygous mis-sense mutation (275G>A) in the cardiac troponin T (TNNT2) gene, which is causally associated with HCM. There have been no previous reports of such extensive, atypical pattern of myocardial scarring despite an otherwise structurally and functionally normal left ventricle in an asymptomatic individual with HCM. This finding has important implications for phenotype screening in HCM.     

Diffuse myocardial fibrosis in hypertrophic cardiomyopathy can be identified by cardiovascular magnetic resonance,and is associated with left ventricular diastolic dysfunction

Background

The presence of myocardial fibrosis is associated with worse clinical outcomes in hypertrophic cardiomyopathy (HCM). Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) sequences can detect regional, but not diffuse myocardial fibrosis. Post-contrast T₁ mapping is an emerging CMR technique that may enable the non-invasive evaluation of diffuse myocardial fibrosis in HCM. The purpose of this study was to non-invasively detect and quantify diffuse myocardial fibrosis in HCM with CMR and examine its relationship to diastolic performance.

Methods

We performed CMR on 76 patients - 51 with asymmetric septal hypertrophy due to HCM and 25 healthy controls. Left ventricular (LV) morphology, function and distribution of regional myocardial fibrosis were evaluated with cine imaging and LGE. A CMR T₁ mapping sequence determined the post-contrast myocardial T₁ time as an index of diffuse myocardial fibrosis. Diastolic function was assessed by transthoracic echocardiography.

Results

Regional myocardial fibrosis was observed in 84% of the HCM group. Post-contrast myocardial T₁ time was significantly shorter in patients with HCM compared to controls, consistent with diffuse myocardial fibrosis (498 ± 80 ms vs. 561 ± 47 ms, p < 0.001). In HCM patients, post-contrast myocardial T₁ time correlated with mean E/e’ (r = −0.48, p < 0.001).

Conclusions

Patients with HCM have shorter post-contrast myocardial T₁ times, consistent with diffuse myocardial fibrosis, which correlate with estimated LV filling pressure, suggesting a mechanistic link between diffuse myocardial fibrosis and abnormal diastolic function in HCM.     

Clinical Utility of Cardiovascular Magnetic Resonance in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by substantial genetic and phenotypic heterogeneity, leading to considerable diversity in clinical course including the most common cause of sudden death in young people and a determinant of heart failure symptoms in patients of any age. Traditionally, two-dimensional echocardiography has been the most reliable method for establishing a clinical diagnosis of HCM. However, cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as a technique particularly well suited to characterize the diverse phenotypic expression of this complex disease. For example, CMR is often superior to echocardiography for HCM diagnosis, by identifying areas of segmental hypertrophy (ie., anterolateral wall or apex) not reliably visualized by echocardiography (or underestimated in terms of extent). High-risk HCM patient subgroups identified with CMR include those with thin-walled scarred LV apical aneurysms (which prior to CMR imaging in HCM remained largely undetected), end-stage systolic dysfunction, and massive LV hypertrophy. CMR observations also suggest that the cardiomyopathic process in HCM is more diffuse than previously regarded, extending beyond the LV myocardium to include thickening of the right ventricular wall as well as substantial morphologic diversity with regard to papillary muscles and mitral valve. These findings have implications for management strategies in patients undergoing invasive septal reduction therapy. Among HCM family members, CMR has identified unique phenotypic markers of affected genetic status in the absence of LV hypertrophy including: myocardial crypts, elongated mitral valve leaflets and late gadolinium enhancement. The unique capability of contrast-enhanced CMR with late gadolinium enhancement to identify myocardial fibrosis has raised the expectation that this may represent a novel marker, which may enhance risk stratification. At this time, late gadolinium enhancement appears to be an important determinant of adverse LV remodeling associated with systolic dysfunction. However, the predictive significance of LGE for sudden death is incompletely resolved and ultimately future large prospective studies may provide greater insights into this issue. These observations underscore an important role for CMR in the contemporary assessment of patients with HCM, providing important information impacting diagnosis and clinical management strategies.     

磁共振特征性追踪技术对肥厚型心肌病心肌应变的初步研究

目的采用心脏磁共振特征性追踪(cardiovascular magnetic resonance feature tracking,CMR-FT)技术对肥厚型心肌病患者的心功能及心肌节段应变进行分析,探讨CMR-FT对肥厚性心肌病患者早期运动异常检测的可行性。材料与方法对17例肥厚型心肌病患者及14名健康志愿者进行3.0 T SSFP电影序列扫描,使用CVI软件检测心功能,并对48个肥厚的心肌节段及健康志愿者中42个正常心肌节段进行特征性追踪(feature tracking,FT)后处理。结果肥厚型心肌病患者与健康志愿者左心功能参数(左心室舒张末期容积、左心室收缩末期容积及左心室射血分数)的差异无统计学意义(P均0.05),肥厚的心肌节段的圆周应变、长轴应变及峰值收缩期圆周应变、峰值收缩期长轴应变均低于正常的心肌节段[(-5.26±2.70)%vs(-11.68±2.06)%,(-7.92±5.07)%vs(-13.93±3.89)%,(-10.44±5.46)%vs(-18.43±2.99)%,(-12.29±8.17)%vs(-20.26±2.93)%,P均0.05]。结论对于心功能正常的肥厚性心肌病患者,CMR-FT技术能够早期检测出肥厚患者肥厚心肌节段应变的变化,提示心肌应变量的改变能够比左心室功能参数更早地发现心肌收缩功能异常。     

Evaluation of apical pouches in hypertrophic cardiomyopathy using cardiac MRI

The presence of apical pouches in hypertrophic cardiomyopathy (HCM) may portend poor prognosis. We sought to study if the use cardiac magnetic resonance imaging (CMR) improves the detection of apical pouches in HCM compared to echocardiography. A retrospective review was performed of all consecutive HCM patients with an apical pouch identified by CMR at Mayo Clinic from May 2004 to Sept 2011. Clinical data was abstracted and CMR and echocardiographic images were analyzed. There were 56 consecutive HCM patients with an apical pouch identified by CMR. The predominant morphological type was apical in 41 (73.2 %), followed by sigmoid in 6 (10.7 %), reversed curve in 6 (10.7 %) and neutral in 3 (5.4 %). Obstructive physiology or systolic anterior motion of the mitral valve leaflet was evident in 23 (41.1 %). Late gadolinium enhancement was present in 47 (87.0 %) patients. Apical pouches were detected in only 18 (32.1 %) patients on echocardiography. Even when intravenous contrast was used (29/56 patients), in 16/29 (55.2 %) pouches were missed on echocardiography. Pouch length and neck dimensions in systole and diastole, measured on CMR, were larger among those patients in whom pouches were detected on echocardiography suggesting only larger pouches can be identified on echocardiography. In the largest CMR series to date of apical pouches in HCM, we show that while apical pouches are most commonly seen in apical HCM, they can be found in other phenotypic variants. CMR is better suited for the evaluation of apical pouches compared to echocardiography even with the use of intravenous contrast. CMR is likely a better tool for evaluating the cardiac apical structures including apical pouches when clinically indicated.     

Extent of myocardial hyperenhancement on late gadolinium-enhanced cardiovascular magnetic resonance correlates with q waves in hypertrophic cardiomyopathy.

PURPOSE: Despite several electrocardiographic, echocardiographic, electrophysiologic and pathologic studies, the cause of abnormal Q waves in patients with HCM remains unclear. Cardiovascular magnetic resonance (CMR) is a powerful in vivo diagnostic tool for evaluating cardiac morphology and function. We hypothesized that estimation of segmental and transmural extent of myocardial enhancement by late gadolinium enhancement (LGE) CMR could clarify the basis of Q waves. The purpose of this prospective study was to evaluate the morphological basis of abnormal Q waves in hypertrophic cardiomyopathy (HCM) as assessed by CMR. METHODS: Thirty-eight patients with HCM underwent gadolinium-enhanced CMR and 12 lead electrocardiography (ECG). Left ventricular function, volumes, segmental and transmural extent of myocardial LGE were assessed and analysed in relation to the presence of abnormal Q waves. RESULTS: Twelve (31%) of the 38 patients had abnormal Q waves on the ECG. Patients with Q waves exhibited significantly more myocardial LGE segmentally as well as transmurally than patients without Q waves. As the segmental and the transmural extent of LGE increased, the probability of Q wave increased (anterior: segmental extent chi2 = 10, p = 0.0013, transmural extent chi2 = 10, p = 0.0013; inferior: segmental extent chi2 = 13, p = 0.0003, transmural extent chi2 = 15, P < 0.0001: lateral: segmental extent chi2 = 10, p = 0.0016, transmural extent chi2 = 10, p = 0.0012). Additionally, the ratio of septal to posterior wall thickness was significantly higher in patients with Q waves than in patients without Q waves (2.3 vs. 1.6, p = 0.012). CONCLUSIONS: It seems that segmental and transmural extent rather than the mere presence of myocardial LGE is the underlying mechanism of abnormal Q waves in HCM. Additionally, distribution of hypertrophy as indicated by differences in the ratio of septal to posterior wall thickness seems to play an important role.     

The diagnosis of hypertrophic cardiomyopathy by cardiovascular magnetic resonance

Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease.