Noninvasive indexes of left atrial diastolic function in hypertrophic cardiomyopathy.

OBJECTIVES: Our goal was to noninvasively assess left atrial diastolic function and its relation to the impaired left ventricular filling in patients with hypertrophic cardiomyopathy. METHODS AND RESULTS: We studied 34 patients with hypertrophic cardiomyopathy, 26 patients with secondary forms of left ventricular hypertrophy (aortic stenosis, fixed subaortic stenosis, hypertension), and 21 control subjects. Left atrial diastolic function was assessed by measuring acceleration time (SAT), deceleration time (SDT), and the EF (mean deceleration rate) slope of the pulmonary venous flow systolic wave (SW). Left ventricular diastolic function assessed by transmitral Doppler included peak early left ventricular and peak atrial filling velocities, the ratio of early-to-late peak velocities, isovolumic relaxation time, deceleration time, and EF slope. In patients with hypertrophic cardiomyopathy, acceleration time was significantly reduced (P<.05), deceleration time was significantly prolonged (P<.0001), and EF slope was significantly reduced (P<.01). These indexes were similar among the other two groups. No statistically significant difference existed between the subgroups of hypertrophic cardiomyopathy in the above indexes. Patients with hypertrophic cardiomyopathy and secondary forms of left ventricular hypertrophy had evidence of left ventricular diastolic dysfunction. In patients with hypertrophic cardiomyopathy, no correlation existed between left atrial and left ventricular diastolic function indexes (r = -0.26 to 0.33). CONCLUSIONS: Echocardiographic indexes of left atrial relaxation and filling are abnormal in patients with hypertrophic cardiomyopathy but not in secondary forms of left ventricular hypertrophy. These indexes are abnormal in all forms of hypertrophic cardiomyopathy irrespective of left ventricular outflow tract obstruction and distribution of hypertrophy; they are not solely attributable to left ventricular diastolic dysfunction. The above may imply that hypertrophic cardiomyopathy is a cardiac myopathic disease that involves the heart muscle as a whole, irrespective of distribution of hypertrophy and obstruction.     

Athlete’s heart or hypertrophic cardiomyopathy?

Intensive endurance training is able to cause a distinct pattern of functional and structural changes of the cardiovascular system. In an unknown proportion of athletes a so called “athlete’s heart” develops. There is an overlap between this type of physiologic cardiac hypertrophy and mild forms of hypertrophic cardiomyopathy (HCM), the most common genetic disorder of the cardiovascular system with a prevalence of 0.2%. HCM is caused by mutations in 14 genes coding for sarcomere proteins. In the literature up to 50% of cases of sudden cardiac death (SCD) in younger sportsmen were connected to hypertrophic cardiomyopathy. It is therefore the most common cause of SCD in highly trained young athletes. Because of this data a great interest in distinguishing these two diagnoses exists. Apart from clinical examination and some non-specific ECG-changes, Echocardiography is the method of choice. The athlete’s heart shows an eccentric biventricular hypertrophy with wall thicknesses under 15 mm and a moderately dilated left ventricle (LVEDD up to 58 mm). HCM is commonly characterized by asymmetric left ventricular hypertrophy with a reduced LV-diameter. In up to 70% of cases left ventricular outflow tract obstruction is evident during stress echocardiography. Systolic function is normal in highly trained athletes and the majority of HCM patients as well. There are important differences regarding diastolic filling patterns. Physiological hypertrophy is consistent with a normal diastolic function with even increased early diastolic filling. In case of HCM diastolic dysfunction (mostly relaxation disturbances) occurs in the majority of patients and is therefore inconsistent with an athlete’s heart. If the diagnosis could not be stated using echocardiography, methods like cardiac-MRI, metabolic exercise testing, histological studies of endomyocardial biopsies and genetic testing can provide further information. A correct diagnosis may on the one hand prevent some athletes from sudden cardiac death. On the other hand sportsmen with an athlete’s heart are reassured and able to continue as competitors. New insights into electrophysiological changes during physiological hypertrophy could probably change this view.     

实时三维超声心动图评价左室心肌肥厚患者的心肌收缩同步性

目的应用实时三维超声心动图（RT3DE）检测左室心肌肥厚（LVH）对左室收缩同步性的影响。方法76例LVH患者分为肥厚型心肌病组（HCM组，34例）和高血压性心脏病组（HHD组，42例），RT3DE测量心率校正的16节段达收缩末最小容积的差值和标准差（Tmsv 16-Dif和Tmsv 16-SD）作为收缩同步性参数，并与对照组（Con组，40例）比较。结果HCM组的Tmsv 16-Dif和Tmsv 16-SD均显著高于HHD组和Con组，但HHD组和Con组之间无显著差异。结论LVH并不总是合并左室收缩不同步，HCM左室收缩同步性下降，而HHD左室同步收缩。RT3DE可同时检测左室16个节段的收缩同步性。     

Adaptative or maladaptative hypertrophy,different spatial distribution of myocardial contraction

Background: Left ventricular hypertrophy (LVH) may be an adaptative remodelling process induced by physical training, or result from pathological stimuli. We hypothesized that different LVH aetiology could lead to dissimilar spatial distribution left ventricular (LV) contraction, and compared different components of LV contraction using 2‐dimensional (2‐D) speckle tracking derived strain in subjects with adaptative hypertrophy (endurance athletes), maladaptative hypertrophy (hypertensive patients) and healthy controls. Method: We enrolled 22 patients with essential hypertension, 50 endurance athletes and 24 healthy controls. All subjects underwent traditional echocardiography and 2‐D strain evaluation of LV longitudinal, circumferential and radial function. LV basal and apical rotation and their net difference, defined as LV torsion, were evaluated. Results: LV wall thicknesses, LV mass and left atrium diameter were comparable between hypertensive group and athletes. LV longitudinal strain was reduced only in hypertensive patients (P < 0·05). LV apex circumferential strain was higher in hypertensive patients than in other groups (P < 0·001), LV basal circumferential strain, although slightly increased, did not reach significant difference. Hypertensive patients showed significantly increased rotation and torsion (P < 0·001), while no differences were observed between athletes and control. Conclusion: In patients with pathological LVH, LV longitudinal strain was reduced, while circumferential deformation and torsion were increased. No differences were observed in LV contractile function between subjects with adaptative LVH and controls. In pathological LVH, increasing torsion could be considered a compensatory mechanism to counterbalance contraction and relaxation abnormalities to maintain a normal LV output.     

组织多普勒评价室壁肥厚与左室局部及整体舒张功能的关系

目的　应用脉冲组织多普勒( TDI)技术分析左室肥厚( L VH)患者局部室壁厚度、室壁不对称性与左室局部及整体舒张功能间的相关关系。方法　左室肥厚患者4 2例,包括肥厚型心肌病( HCM) 1 6例和高血压性心脏病( HHD)左室肥厚2 6例;正常对照( NC) 2 0例。二维超声测量并计算左室8个节段室壁厚度( r WT)、总厚度( t WT)及室壁不对称指数( CVw) ;TDI测量8个心肌节段的舒张期运动速度比( r E/ A)和等容舒张时间( r IVRT) ;另外分别应用TDI和脉冲波多普勒测量二尖瓣环和二尖瓣口的舒张期参数m E/ A、m IVRT和PVE/ PVE,IVRT作为整体舒张功能指标。结果　( 1 ) L VH者室壁总厚度及其不对称指数、局部等容舒张时间及其舒张不同步性均高于NC组;( 2 )室壁肥厚的程度及其不对称性与左室整体舒张功能相关( r值的绝对值0 .1 8～0 .4 1 ,P<0 .0 5 ) ;( 3 )局部r WT与r E/ A、r IVRT相关( r值- 0 .4 6 ,0 .4 1 ,P<0 .0 5 )。结论　肥厚型心肌病和高血压性心肌肥厚患者的局部室壁肥厚程度与左室局部舒张功能减低及等容舒张期延长有关;左室壁不对称性肥厚通过影响左室局部心肌早期舒张的速度和同步性间接导致左室整体早期充盈异常;TDI技术用于非创伤性评价左室局部及整体舒张功能有一定价值     

Advanced Anderson-Fabry disease presenting with left ventricular apical aneurysm and ventricular tachycardia

A 54-year-old female with Anderson-Fabry disease(AFD)-R342 Q missense mutation on exon 7 in alphagalactosidase A(GLA) gene- presented with sustained ventricular tachycardia. Imaging confirmed the presence of a new left ventricular apical aneurysm(LVAA) and a significantly reduced intra-cavitary gradient compared to two years prior. AFDcv is an X-linked lysosomal storage disorder caused by GLA enzyme deficiency. The phenotypic expression of AFD in the heart is not well described. Cardiac involvement can include left ventricular hypertrophy(LVH), which is typically symmetric, but can also mimic hypertrophic cardiomyopathy(HCM). Left ventricular apical aneurysm is a rare finding in HCM. We suggest a shared mechanism of LVAA formation in AFD and HCM, independent of the underlying cardiomyopathy. Mechanisms of LVAA formation in HCM include genetic predisposition and long-standing left ventricular wall stress from elevated intra-cavitary systolic pressures due to mid-cavitary obstruction. Both mechanisms are supported in this patient(a brother with AFD also developed a small LVAA). Screening for AFD should be considered in cases of unexplained LVH, particularly in patients with the aneurysmal variant of HCM.     

Current approaches to assessment of left ventricular hypertrophy. Aspects of differential diagnosis

Recommendations are proposed how to assess left ventricular hypertrophy (LVH) as well as a complex approach to examination of the heart structure and function in patients with different diseases accompanied with LVH development. LVH differential diagnosis is considered in arterial hypertension (AH), hypertrophic cardiomyopathy (HCMP), accumulation myocardial diseases, non-compact myocardium, valvular and combined cardiac pathology, compensatory LVH in athletes. Novel echocardiological techniques are recommended for use in complicated diagnostic cases. Normal parameters and criteria of LVH severity by thickness of the wall and left ventricular indexed mass according to the latest recommendations of the European and American echocardiology associations are listed.     

高血压左室肥厚与肥厚性心肌病心肌声学密度的比较

目的：旨在通过采用计算机辅助的声学组织密度定量技术分别对设备在压左室肥厚（ＬＶＨ）及肥厚性心肌病（ＨＣＭ）患者的心肌组织灰阶段特征进行了分析,以期评价该方法鉴别不同病因心肌最的可行性,材料和方法,研究对象为３２例正常人,２８例ＬＶＨ的高血压病人的３５例ＨＣＭ患者,常规以二尖瓣和乳头肌水平的短轴切面。采用Ｗｉｎｄｏｗｓ９５支持下的Ｐｈｏｔｏ－Ｓｈｏｐ３．０５软件对图像进行分析,结果：ＨＣＭ患得肥厚的     

Polymorphisms of the peroxisome proliferator-activated receptor-gamma coactivator-1alpha gene are associated with hypertrophic cardiomyopathy and not with hypertension hypertrophy.

BACKGROUND: The clinical phenotype of both hypertrophic cardiomyopathy (HCM) and left ventricular hypertrophy (LVH) induced by hypertension is heterogeneous. Genetic factors may contribute to this heterogeneity. Evidence is accumulating that the peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) gene plays a role in cardiac hypertrophy. The aim of our study was to identify the association between PGC-1alpha gene polymorphisms and cardiac hypertrophy. METHODS: A total of 270 consecutive HCM patients and 2486 hypertensive patients, comprising 1180 with LVH and 1306 without LVH, as well as 894 healthy controls, were successfully investigated. Polymorphisms of the PGC-1alpha gene were genotyped by PCR-restriction fragment length polymorphism and confirmed by sequencing. RESULTS: The Ser482 allele (rs8192678 G>A and A>A) and CC genotype of Thr394Thr (rs2970847) conferred increased risk for HCM [odds ratio (OR) 1.52, 95% confidence interval (CI) 1.11-2.11; OR 1.49, 95% CI 1.15-1.98, respectively]. The maximum ventricular thickness was greater in HCM patients carrying the Ser482 risk allele than in carriers of the non-risk allele (20.7+/-4.1 vs. 19.1+/-4.3 mm, p<0.05) and for the CC Thr394Thr genotype (20.9+/-4.6 vs. 19.0+/-4.2 mm, p<0.05). No association was found between PGC-1alpha polymorphism and hypertension with or without LVH. Conclusions: Our data indicate that variants of the PGC-1alpha gene are correlated with increased risk for HCM.     

高血压病患者左室舒张功能的研究

目的 研究高血压病患者左室舒张功能的变化。方法 二维超声检测高血压组72例(左室肥厚35例、非肥厚组37例)、对照组30例的左房大小、室间隔厚度(IVST)、左室后壁厚度，多普勒测定二尖瓣血流频谱及左室等容舒张时间(IVRT)。结果 高血压组与对照组比较：左房明显扩大，室间隔及左室后壁明显增厚，E峰、Ei显著减小，A峰、Ai显著增高，WRT显著延长。高血压组中，左室肥厚组与非肥厚组比较：肥厚组左房扩大，室间隔及左室后壁增厚，E峰、Ei减小，A峰、Ai增高，IVRT延长均较非肥厚组明显。结论 高血压病患者存在左室舒张功能异常，左室肥厚者舒张功能的损害更为严重。     

Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance

Background

Cardiovascular magnetic resonance (CMR) is the gold standard non-invasive method for determining left ventricular (LV) mass and volume but has not been used previously to characterise the LV remodeling response in aortic stenosis. We sought to investigate the degree and patterns of hypertrophy in aortic stenosis using CMR.

Methods

Patients with moderate or severe aortic stenosis, normal coronary arteries and no other significant valve lesions or cardiomyopathy were scanned by CMR with valve severity assessed by planimetry and velocity mapping. The extent and patterns of hypertrophy were investigated using measurements of the LV mass index, indexed LV volumes and the LV mass/volume ratio. Asymmetric forms of remodeling and hypertrophy were defined by a regional wall thickening ≥13 mm and >1.5-fold the thickness of the opposing myocardial segment.

Results

Ninety-one patients (61±21 years; 57 male) with aortic stenosis (aortic valve area 0.93±0.32cm2) were recruited. The severity of aortic stenosis was unrelated to the degree (r²=0.012, P=0.43) and pattern (P=0.22) of hypertrophy. By univariate analysis, only male sex demonstrated an association with LV mass index (P=0.02). Six patterns of LV adaption were observed: normal ventricular geometry (n=11), concentric remodeling (n=11), asymmetric remodeling (n=11), concentric hypertrophy (n=34), asymmetric hypertrophy (n=14) and LV decompensation (n=10). Asymmetric patterns displayed considerable overlap in appearances (wall thickness 17±2mm) with hypertrophic cardiomyopathy.

Conclusions

We have demonstrated that in patients with moderate and severe aortic stenosis, the pattern of LV adaption and degree of hypertrophy do not closely correlate with the severity of valve narrowing and that asymmetric patterns of wall thickening are common.

Trial registration

ClinicalTrials.gov Reference Number: NCT00930735     

Differential diagnosis of idiopathic cardiomyopathy from ischemic cardiomyopathy and hypertensive heart disease using non-invasive methods

Although, the diagnosis of idiopathic cardiomyopathy is determined by cardiac catheterization including myocardial biopsy, non-invasive diagnosis is important. The most useful method is nuclear cardiology to differentiate dilated cardiomyopathy from ischemic cardiomyopathy. Cardiac images in ischemic cardiomyopathy have wider perfusion and metabolic defects than in dilated cardiomyopathy using Tl-201, Tc-99m perfusion tracers, I-123 BMIPP, N-13 NH3 and F-18 FDG. The degree of heterogenecity of the myocardium is higher in ischemic cardiomyopathy than in dilated cardiomyopathy by these tracers. Left ventricular hypertrophy is common finding in hypertension and hypertrophic cardiomyopathy. However, in hypertensive heart disease the left ventricular wall thickness rarely exceed than 20 mm, and the septal wall thickness/posterior wall thickness is not more than 1.5, which are frequently shown in hypertrophic cardiomyopathy. Right ventricular hypertrophy near the ventricular septum is also one of the characteristic findings in hypertrophic cardiomyopathy.     

Two-dimensional strain analysis of the global and regional myocardial function for the differentiation of pathologic and physiologic left ventricular hypertrophy: a study in athletes and in patients with hypertrophic cardiomyopathy

Two-dimensional strain (2DS) is a novel method to measure strain from standard two-dimensional echocardiographic images by speckle tracking, which is less angle dependent and more reproducible than conventional Doppler-derived strain. The objective of our study was to characterize global and regional function abnormalities using 2DS and strain rate analysis in patients (pts) with pathological left ventricular hypertrophy (LVH) caused by non-obstructive hypertrophic cardiomyopathy (HCM), in top level athletes, and in healthy controls. The hypothetical question was, if 2DS might be useful as additional tool in differentiating between pathologic and physiologic hypertrophy in top-level athletes. We consecutively studied 53 subjects, 15 pts with hypertrophic cardiomyopathy (HCM), 20 competitive top-level athletes, and a control group of 18 sedentary normal subjects by standard echocardiography according to ASE guidelines. Global longitudinal strain (GLS) and regional peak systolic strain (PSS) was assessed by 2DS in the apical four-chamber-view using a dedicated software. All components of strain were significantly reduced in pts with HCM (GLS: −8.1 ± 3.8%; P < 0.001) when compared with athletes (−15.2 ± 3.6%) and control subjects (−16.0 ± 2.8%). In general, there was no significant difference between the strain values of the athletes and the control group, but in some of the segments, the strain values of the control group were significantly higher than those in the athletes. A cut-off value of GLS less than −10% for the diagnosis of pathologic hypertrophy (HCM) resulted in a sensitivity of 80.0% and a specificity of 95.0%. The combination of TDI (averaged S′, E′) and 2DS (GLS) cut-off values for the detection of pathologic LVH in HCM demonstrated a sensitivity of 100%, and a specificity of 95%. Two-dimensional strain is a new simple and rapid method to measure GLS and PSS as components of systolic strain. This technique could offer a unique approach to quantify global as well as regional systolic dysfunction, and might be used as new additional tool for the differentiation between physiologic and pathologic LVH.     

高血压病左心功能相关性的超声研究

目的 探讨高血压病左心房与左心室功能的相关关系。方法 对照组20例，高血压病左心室心肌质量指数(LVMI)正常组32例，高血压病左心室肥厚组16例，采用声学定量技术，测量左心房助力泵功能(LAEF、AE)、管道功能(CV)和储存器功能(RV)以及左心室舒张功能。结果 左心房助力泵功能与其主动收缩前容量、RV正相关，与CV及左心室舒张功能负相关；左心房管道功能与AE、LAEF、RV和左心房主动收缩前容量显著负相关，与左心室舒张功能正相关；左心房储存器功能与左心房主动收缩前容量、LAEF正相关，与CV负相关，与左心室舒张功能指标无显著相关。结论 高血压病左心室舒张功能减退导致左心房管道功能减低、肺静脉与左心房间压差增大、左心房储存器功能增强、左心室舒张早期充盈增加，而管道功能与储存器功能的改变导致左心房前负荷增加和左心房收缩能力增强、左心房助力泵功能增强、左心室舒张晚期充盈增加。     

Differences in left ventricular diastolic dysfunction between eccentric and concentric left ventricular hypertrophy in hypertensive patients with preserved systolic function

Left ventricular (LV) hypertrophy (LVH) may be eccentric or concentric (2 × LV posterior wall thickness relative to LV end-diastolic dimension ≤ 0.42 or > 0.42, respectively). The LV diastolic function between age-matched hypertensive patients with eccentric and concentric LVH was compared in the present study. Echocardiography was used to measure LV mass index (LV mass/body surface area; LVMI) as an index of LVH. LV diastolic function was assessed by measurements of peak early transmitral flow velocity (E)/peak late transmitral flow velocity (A) (the E/A ratio), peak early diastolic mitral annular velocity (e') and the E/e' ratio. Although LVMI, E/A and e' did not differ between the two groups, E/e' was significantly higher (worse) in patients with concentric LVH (13.4 ± 5.4) than in those with eccentric LVH (11.1 ± 3.6). Among hypertensive patients with LVH, those with concentric LVH may, therefore, have more severe LV diastolic dysfunction than those with eccentric LVH even if their LVMIs, which reflect the degree of LVH, are similar.     

Degree and distribution of left ventricular hypertrophy as a determining factor for elevated natriuretic peptide levels in patients with hypertrophic cardiomyopathy: insights from cardiac magnetic resonance imaging

Whether the left ventricular (LV) mass index (LVMI) and LV volumetric parameters are associated independently with natriuretic peptide levels is unclear in hypertrophic cardiomyopathy (HCM). Therefore, we investigated which parameters have an independent relationship with N-terminal pro-B type natriuretic peptide (NT-proBNP) levels in HCM patients using echocardiography and cardiac magnetic resonance imaging (CMR). A total of 103 patients with HCM (82 men, age 53 ± 12 years) were evaluated. Echocardiographic evaluations included left atrial volume index (LAVI) and early diastolic mitral inflow E velocity to early annular Ea velocity ratio (E/Ea). LVMI, maximal wall thickness and LV volumetric parameters were measured using CMR. The median value of NT-proBNP level was 387.0 pg/ml. The mean NT-proBNP level in patients with non-apical HCM (n = 69; 36 patients with asymmetric septal hypertrophy, 11 with diffuse, and 22 with mixed type) was significantly higher than in those with apical HCM (n = 34, P < 0.001). NT-proBNP level was negatively correlated with LV end-diastolic volume (LVEDV) (r = -0.263, P = 0.007) and positively with LVMI (r = 0.225, P = 0.022) and maximal wall thickness (r = 0.495, P < 0.001). Among the echocardiographic variables, LAVI (r = 0.492, P < 0.001) and E/Ea (r = 0.432, P < 0.001) were correlated with NT-proBNP. On multivariable analysis, non-apical HCM, increased maximal wall thickness and LAVI were independently related with NT-proBNP. Severity of LV hypertrophy and diastolic parameters might be important in the elevation of NT-proBNP level in HCM. Therefore, further evaluation of these parameters in HCM might be warranted.     

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。     

速度向量成像技术评价肥厚型心肌病左心室扭转功能

目的应用超声心动图速度向量成像技术对肥厚型心肌病患者心脏扭转运动进行初步分析,探讨肥厚型心肌病患者在左心室射血分数(LVEF)正常时心脏局部和整体扭转功能是否有改变。方法肥厚型心肌病患者和健康体检者各30名。常规测量有关左心功能参数:LVEF、舒张末期容积(EDV)、收缩末期容积(ESV)、每搏量(SV)、二尖瓣口E、A峰值血流速度等。速度向量成像模式下在系列胸骨旁短轴观图像上测量收缩期心内膜下和心外膜下心肌的最大旋转角度、峰值旋转速率、圆周应变(CS)、圆周应变率(CSR)、舒张期和等容舒张期峰值解旋转速率。结果肥厚型心肌病组EDV、ESV、SV明显减低,A峰增高(P0.01);心内膜下心肌左心室扭转角度和扭矩增高,解扭转率减低(P0.05);心外膜下心肌的基底部峰值旋转速率、峰值解旋转速率减低(P0.05);心外膜下心肌的CS、CSR明显减低(P0.05)。结论肥厚型心肌病患者心脏整体扭转角度和速度较正常人增高,局部心肌圆周方向形变能力下降,以心外膜下心肌下降更为明显。     

基于深度学习的1.5T心脏磁共振Cine序列在肥厚型心肌病和扩张型心肌病患者左心室功能评估中的应用

目的:探讨一种基于深度学习的1.5T心脏磁共振Cine序列自动量化不同心肌病左心室功能的性能。方法:回顾性分析2014年3月至2019年11月393例心脏MRI受检者的相关临床资料。对肥厚型心肌病(HCM)患者(HCM组,n=125)、扩张型心肌病(DCM)患者(DCM组,n=133)和健康个体(对照组,n=135)的左心室功能,分别通过手动和自动测量进行评估。手动分析由2位经验丰富的医师完成;自动分析后,从左心室分割精度和左心室功能参数准确性两方面对卷积神经网络(CNN)的性能进行评价。采用Pearson相关分析、Bland-Altman分析和受试者工作特征曲线(ROC),评价手动与自动方法诊断HCM和DCM的相关性与一致性。结果:CNN评估左心室功能时,在HCM组中与手动分析的一致性最好,对照组次之,在DCM中表现最差。HCM组左心室功能4个参数的自动分析与手动分析结果具有较高的相关性(P0.01);DCM组所有参数自动与手动分析的相关性均弱于HCM,特别是射血分数和每搏输出量。ROC曲线分析表明,自动分割算出的射血分数对DCM、HCM的诊断灵敏度分别为92.31%和78.05%,特异度分别为82.96%和54.07%。结论:在不同心肌疾病中,基于CNN的心功能分析性能可能不同,在HCM中表现优于DCM,但对DCM的诊断价值优于HCM。     

Early gadolinium enhancement in hypertrophic cardiomyopathy: a potential premature marker of myocardial damage

Early gadolinium enhancement (EGE), one CMR diagnostic criteria in acute myocarditis, has been related with hyperemia and capillary leakage. The value of EGE in hypertrophic cardiomyopathy (HCM) remains unknown. Our aim was to determine the prevalence of EGE in patients with HCM, and its relation with late gadolinium enhancement (LGE). The association of EGE with morphological and clinical parameters was also evaluated. Sixty consecutive patients with HCM and CMR from our center were included. All the clinical and complementary test information was collected prospectively in our HCM clinic. Left ventricular (LV) measurements were calculated from cine sequences. EGE and LGE were quantified with a dedicated software. Clinical events were collected from medical records. A slow wash-out pattern on EGE was detected in up to 68?% of the patients, being an isolated finding without LGE in 10 (16?%). This cohort showed a greater maximal LV wall thickness (20.1?±?4 vs. 18.1?±?3.5 mm, p?=?0.010) and asymmetry ratio (1.86?±?0.42 vs. 1.62?±?0.46; p?=?0.039). The percentage of EGE/slice and the difference with the percentage LGE/slice demonstrated a significant positive correlation with the maximal LV wall thickness (Rho 0.450 and 0.386 respectively). EGE also correlated with number of segments with LVH (LV hypertrophy) and the asymmetry ratio. Neither EGE nor LGE were associated with classical risk factors, the risk score for sudden cardiac death, or with major clinical events. EGE was a frequent finding in HCM, even in absence of LGE. This phenomenon showed a positive correlation with morphological markers of disease burden.