T1 mapping in children and young adults with hypertrophic cardiomyopathy

To assess the global and segmental left ventricular (LV) native T1 and extracellular volume fraction (ECV) in children and young adults with hypertrophic cardiomyopathy (HCM) compared to a control cohort. The study population included 21 HCM patients (mean 14.1?±?4.6 years) and 21 controls (mean 15.7?±?1.5 years). Native modified Look-Locker inversion recovery sequence was performed before and after contrast injection in 3 short axis planes. Global and segmental LV native T1 and ECV were quantified and compared between HCM patients and controls. Mean native T1 in HCM patients and controls was 1020.4?±?41.2 and 965.6?±?30.2 ms respectively (p?<?0.0001). Hypertrophied myocardium had significantly higher native global T1 and global ECV compared to non-hypertrophied myocardium in HCM (p?<?0.0001,?=?0.14 and 0.048,?=?0.01 respectively). In a subset of patients, ECV was higher in LV segments with LGE compared to no LGE (p?<?0.0001). No significant correlation was identified between global native T1 and ECV and parameters of LV structure and function. Native T1 cut-off of 987 ms provided the highest sensitivity (95?%) and specificity (91?%) to separate HCM patients from controls. Global and segmental native T1 are elevated in HCM patients. LV segments with hypertrophy and/or LGE had higher ECV in a subset of HCM patients. LV native T1 and ECV do not correlate with parameters of LV structure and function. T1 in children and young adults may be used as a non-invasive tool to assess for HCM and related fibrosis.     

The relationship between electrocardiographic changes and CMR features in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy

To investigate the relationship between electrocardiographic (ECG) abnormalities and left ventricular (LV) segmental hypertrophy and myocardial fibrosis assessed by cardiovascular magnetic resonance (CMR) in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy (HCM). 118 asymptomatic or mildly symptomatic patients with HCM were examined with late gadolinium enhancement (LGE) CMR, 12-lead ECG, and echocardiography. The distribution and magnitude of LV segmental hypertrophy and LGE were assessed and analyzed in relation to ECG abnormalities. Abnormal electrocardiograms were found in 113 of 118 (95 %) patients. Negative T waves were associated with greater apical septal thickness (P = 0.009) and an increased ratio of LV septum to free wall thickness (P = 0.01). Giant negative T waves (GNT) were found in 19 patients (16 %), and were associated with apical HCM (P < 0.001), greater apical thickness (P = 0.004), and increased ratio of LV apical to basal wall thickness (P < 0.001). However, no significant association was demonstrated between GNT and apical LGE (P = 0.71). Abnormal Q waves were associated with greater basal anteroseptal thickness (P = 0.001), maximal basal thickness (P = 0.004), and more segments with extensive LGE (>75 % wall thickness involved) (P = 0.001). LV hypertrophy was related to greater LV mass (P = 0.002) and LV end diastolic volume (P = 0.002). In addition, a modest but significant correlation was observed between maximum LV wall thickness and the Romhilt-Estes score (r = 0.41, P < 0.001). GNT were associated with apical HCM and an increased ratio of LV apical to basal wall thickness. Abnormal Q waves were related to basal anteroseptal hypertrophy and segmental extensive LGE.     

磁共振T1 mapping成像评价肥厚型和扩张型心肌病弥漫性心肌纤维化

目的 探讨磁共振纵向弛豫时间定量(T1 mapping)成像评价肥厚型心肌病(HCM)和扩张型心肌病(DCM)心肌纤维化的价值,及心肌纤维化与左心室射血分数的关系。方法 收集经临床诊断证实的30例HCM患者(HCM组)、27例DCM患者(DCM)和符合纳入标准的33例患者(对照组)。对所有受检者均行心脏电影成像、对比增强前、后T1 mapping成像、延迟对比增强(LGE)成像。测量不同受检者增强前、后左心室平均T1值及心功能参数并进行统计学分析,分析心肌平均T1值与心功能指标的相关性。结果 HCM组22例(22/30,73.33%)患者存在延迟强化,DCM组15例(15/27,55.56%)患者存在延迟强化,对照组无延迟强化。比增强前,HCM组[(1294.79±85.22)ms]、DCM组[(1312.88±59.57)ms]左心室心肌T1值均较对照组[(1266.56±57.33)ms]显著增加(P均<0.05);对比增强后,HCM组[(491.31±121.59)ms]、DCM组[(466.77±126.34)ms]左心室心肌T1均值较对照组[(534.09±92.73)]显著减低(P均<0.05)。HCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.58,P<0.05),增强后T1值与其呈正相关(r=0.59,P<0.05);DCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.55,P<0.05),增强后T1值与其呈正相关(r=0.51,P<0.05)。结论 HCM和DCM患者心肌纤维化与心功能相关;T1 mapping成像有助于评价HCM和DCM患者心肌纤维化。     

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.     

Helical distribution of hypertrophy in patients with hypertrophic cardiomyopathy: prevalence and clinical implications

Recently a novel pattern of helical distribution of hypertrophy has been described in patients with hypertrophic cardiomyopathy (HCM). Our aim was to determine its prevalence and potential implications in an unselected cohort. One-hundred- and eight consecutive patients diagnosed with HCM by cardiac magnetic resonance (CMR) were included (median clinical follow up of 1718 days). All clinical and complementary test information was prospectively collected. The presence of a helical pattern was assessed by a simple measurement of the maximal left ventricle (LV) wall thickness (LVWT) for each of the 17 classical LV segments and it was classified in one of three types according to its extension. A helical distribution was detected in 58% of patients, and was associated to a higher incidence of left ventricular outflow tract obstruction (LVOT; 35% vs. 10%; p?=?0.005) and systolic anterior motion of the mitral valve (SAM; 30% vs. 13%, p = 0.053). No significant difference in the maximal LVWT was observed. However, the presence of a helical pattern showed a significant association with non sustained ventricular tachycardia (NSVT; 22% vs. 7%; p?=?0.029) and was associated to a higher risk of sudden cardiac death (SCD) calculated with the European society of cardiology (ESC) calculator (p = 0.006). Notably, patients with a more extense spiral had a higher incidence of heart failure (75% vs. 34%, p = 0.012) and all-cause death (21 vs. 3%, p?=?0.049). A helical pattern is frequent in HCM and can be readily assessed on CMR standard cine sequences. In conclusion, a helical pattern carries negative clinical implications and is associated to a higher estimated risk of SCD.     

Midregional pro-atrial natriuretic peptide: a novel marker of myocardial fibrosis in patients with hypertrophic cardiomyopathy

We aimed to determine the diagnostic performance of biomarkers in predicting myocardial fibrosis assessed by late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) in patients with hypertrophic cardiomyopathy (HCM). LGE CMR was performed in 40 consecutive patients with HCM. Left and right ventricular parameters, as well as the extent of LGE were determined and correlated to the plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP), midregional pro-adrenomedullin (MR-proADM), carboxy-terminal pro-endothelin-1 (CT-proET-1), carboxy-terminal pro-vasopressin (CT-proAVP), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and interleukin-8 (IL-8). Myocardial fibrosis was assumed positive, if CMR indicated LGE. LGE was present in 26 of 40 patients with HCM (65%) with variable extent (mean: 14%, range: 1.3–42%). The extent of LGE was positively associated with MR-proANP (r = 0.4; P = 0.01). No correlations were found between LGE and MR-proADM (r = 0.1; P = 0.5), CT-proET-1 (r = 0.07; P = 0.66), CT-proAVP (r = 0.16; P = 0.3), MMP-9 (r = 0.01; P = 0.9), TIMP-1 (r = 0.02; P = 0.85), and IL-8 (r = 0.02; P = 0.89). After adjustment for confounding factors, MR-proANP was the only independent predictor associated with the presence of LGE (P = 0.007) in multivariate analysis. The area under the ROC curve (AUC) indicated good predictive performance (AUC = 0.882) of MR-proANP with respect to LGE. The odds ratio was 1.268 (95% confidence interval 1.066–1.508). The sensitivity of MR-proANP at a cut-off value of 207 pmol/L was 69%, the specificity 94%, the positive predictive value 90% and the negative predictive value 80%. The results imply that MR-proANP serves as a novel marker of myocardial fibrosis assessed by LGE CMR in patients with HCM.     

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。     

Quantitative diffusion-weighted magnetic resonance imaging in the assessment of myocardial fibrosis in hypertrophic cardiomyopathy compared with T1 mapping

To identify myocardial fibrosis in hypertrophic cardiomyopathy (HCM) subjects using quantitative cardiac diffusion-weighted imaging (DWI) and to compare its performance with native T1 mapping and extracellular volume (ECV). Thirty-eight HCM subjects (mean age, 53?±?9 years) and 14 normal controls (mean age, 51?±?8 years) underwent cardiac magnetic resonance imaging (CMRI) on a 3.0T magnetic resonance (MR) machine with DWI, T1 mapping and late gadolinium enhancement (LGE) imaging as the reference standard. The mean apparent diffusion coefficient (ADC), native T1 value and ECV were determined for each subject. Overall, the HCM subjects exhibited an increased native T1 value (1241.04?±?78.50 ms), ECV (0.31?±?0.03) and ADC (2.36?±?0.34 s/mm²) compared with the normal controls (1114.60?±?37.99 ms, 0.24?±?0.04, and 1.62?±?0.38 s/mm², respectively) (p?<?0.05). DWI differentiated healthy and fibrotic myocardia with an area under the curve (AUC) of 0.93, while the AUCs of the native T1 values (0.93), (p?>?0.05) and ECV (0.94), (p?>?0.05) exhibited an equal differentiation ability. Both HCM LGE+ and HCM LGE? subjects had an increased native T1 value, ECV and ADC compared to the normal controls (p?<?0.05). HCM LGE+ subjects exhibited an increased ECV (0.31?±?0.04) and ADC (2.43?±?0.36 s/mm²) compared to HCM LGE? subjects (p?<?0.05). HCM LGE+ and HCM LGE? subjects had similar native T1 values (1250?±?76.36 ms vs. 1213.98?±?92.30 ms, respectively) (p?>?0.05). ADC values were linearly associated with increased ECV (R²?=?0.36) and native T1 values (R²?=?0.40) among all subjects. DWI is a feasible alternative to native T1 mapping and ECV for the identification of myocardial fibrosis in patients with HCM. DWI and ECV can quantitatively characterize the extent of fibrosis in HCM LGE+ and HCM LGE? patients.     

CMR findings in patients with hypertrophic cardiomyopathy and atrial fibrillation

Objectives

We sought to evaluate the relation between atrial fibrillation (AF) and the extent of myocardial scarring together with left ventricular (LV) and atrial parameters assessed by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM).

Background

AF is the most common arrhythmia in HCM. Myocardial scarring is also identified frequently in HCM. However, the impact of myocardial scarring assessed by LGE CMR on the presence of AF has not been evaluated yet.

Methods

87 HCM patients underwent LGE CMR, echocardiography and regular ECG recordings. LV function, volumes, myocardial thickness, left atrial (LA) volume and the extent of LGE, were assessed using CMR and correlated to AF. Additionally, the presence of diastolic dysfunction and mitral regurgitation were obtained by echocardiography and also correlated to AF.

Results

Episodes of AF were documented in 37 patients (42%). Indexed LV volumes and mass were comparable between HCM patients with and without AF. However, indexed LA volume was significantly higher in HCM patients with AF than in HCM patients without AF (68 ± 24 ml·m^-2 versus 46 ± 18 ml·m^-2, p = 0.0002, respectively). The mean extent of LGE was higher in HCM patients with AF than those without AF (12.4 ± 14.5% versus 6.0 ± 8.6%, p = 0.02). When adjusting for age, gender and LV mass, LGE and indexed LA volume significantly correlated to AF (r = 0.34, p = 0.02 and r = 0.42, p < 0.001 respectively). By echocardiographic examination, LV diastolic dysfunction was evident in 35 (40%) patients. Mitral regurgitation greater than II was observed in 12 patients (14%). Multivariate analysis demonstrated that LA volume and presence of diastolic dysfunction were the only independent determinant of AF in HCM patients (p = 0.006, p = 0.01 respectively). Receiver operating characteristic curve analysis indicated good predictive performance of LA volume and LGE (AUC = 0.74 and 0.64 respectively) with respect to AF.

Conclusion

HCM patients with AF display significantly more LGE than HCM patients without AF. However, the extent of LGE is inferior to the LA size for predicting AF prevalence. LA dilation is the strongest determinant of AF in HCM patients, and is related to the extent of LGE in the LV, irrespective of LV mass.     

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.     

三维斑点追踪成像评价肥厚型心肌病患者左心室整体和局部收缩功能

目的 应用三维斑点追踪成像(3D-STI)检测肥厚型心肌病(HCM)患者左心室心肌整体及各节段峰值应变, 评估HCM左心室收缩功能。方法 收集43例HCM患者(病例组)和23名健康志愿者(对照组), 病例组分为室间隔肥厚型HCM(sHCM)亚组(22例)、心尖肥厚型HCM(aHCM)亚组(8例)和混合型HCM(mHCM)亚组(13例), 对所有受检者进行3D-STI检测, 获得左心室射血分数(LVEF), 左心室心肌整体纵向峰值应变(GPLS)、圆周峰值应变(GPCS)、面积峰值应变(GPAS)、径向峰值应变(GPRS)及各节段峰值应变, 比较组间上述参数差异。结果 病例组LVEF与对照组比较无明显变化(P >0.05)。3D-STI中病例组与对照组比较左心室心肌GPLS、GPAS和GPRS均明显减低(P均 <0.01), GPCS无明显变化;心肌应变减低sHCM亚组主要集中于间隔基底段及中间段, aHCM亚组主要集中于心尖段, mHCM亚组主要集中于中间段及心尖段。结论 HCM患者左心室常规收缩功能参数可正常, 左心室心肌三维纵向应变、面积应变、径向应变减低, 可通过3D-STI进行检测, 不同类型HCM患者应变减低节段分布与肥厚部位有关。     

Quantitative analysis of late gadolinium enhancement in hypertrophic cardiomyopathy: comparison of diagnostic performance in myocardial fibrosis between gadobutrol and gadopentetate dimeglumine

The purpose of this study was to compare different semi-automated late gadolinium enhancement (LGE) quantification techniques using gadobutrol and gadopentetate dimeglumine contrast agents with regard to the diagnosis of fibrotic myocardium in patients with hypertrophic cardiomyopathy (HCM). Thirty patients with HCM underwent two cardiac MRI protocols with use of gadobutrol and gadopentetate dimeglumine. Contrast-to-noise ratio (CNR) between LGE area and remote myocardium (CNRremote), between LGE area and left ventricular blood pool (CNRpool), and signal-to-noise ratio (SNR) in LGE were compared. The presence and quantity of LGE were determined by visual assessment. With signal threshold versus reference mean (STRM) based thresholds of 2 SD, 5 SD, and 6 SD above the mean signal intensity (SI) of reference myocardium, the full-width at half-maximum (FWHM) technique was used. The volume and segments of the LGE area were compared between the two types of contrast agents. LGE was present in 26 of 30 (86.6%) patients in both protocols. The CNRremote of fibrotic myocardium in gadobutrol and gadopentetate dimeglumine agents was 26.82?±?14.24 and 21.46?±?10.59, respectively (P?<?0.05). The CNRpool was significantly higher in gadobutrol (9.32?±?7.64 vs. 6.39?±?6.11, P?<?0.05). The SNR was higher in gadobutrol (33.36?±?14.35 vs. 27.53?±?10.91, P?<?0.05). The volume of scar size in MR images acquired with gadobutrol were significantly higher than those with gadopentetate dimeglumine (P?<?0.05), and the STRM of 5 SD technique showed the greatest agreement with visual assessment (ICC?=?0.99) in both examinations. There was no significant difference in fibrotic segments of the fibrotic myocardium in the LGE area (P?<?0.05). This study proved that the Gadobutrol was an effective contrast agent for LGE imaging with superior delineation of fibrotic myocardium as compared to gadopentetate dimeglumine. The 5 SD technique yields the closest approximation of the extent of LGE identified by visual assessment.     

Cardiac magnetic resonance and galectin-3 level as predictors of prognostic outcomes for non-ischemic cardiomyopathy patients

This study was aimed at determining whether late gadolinium enhancement (LGE) in conjunction with Galectin-3 (Gal-3) level offered more precise prognosis of non-ischemic cardiomyopathy (NICM) in comparison to LGE alone. Results of LGE and Gal-3 expression in 192 patients with NICM, including 85 subjects with dilated cardiomyopathy (DCM) and 107 with hypertrophic cardiomyopathy (HCM), were examined. As suggested by the characteristics of LGE and Gal-3 levels, patients were divided into four groups: LGE positive?+?low Gal-3 (n?=?10 for DCM, n?=?15 for HCM), LGE positive?+?high Gal-3 (n?=?25 for DCM, n?=?51 for HCM), LGE negative?+?low Gal-3 (n?=?32 for DCM, n?=?29 for HCM), LGE negative?+?high Gal-3 (n?=?18 for DCM, n?=?12 for HCM). Primary endpoints over the follow-up period included major adverse cardiac events (MACEs). Kaplan–Meier survival analysis and univariate Cox proportional hazard models were used to analyze the survival status of patients with NICM. The optimal cut-off value of Gal-3 level for two types of NICM was determined by receiver operating characteristic analysis (13.38 U/L for DCM and 14.40 U/L for HCM). The combination of LGE and Gal-3 levels offered a more significant prognostic value than using LGE alone for both DCM and HCM (DCM P?=?0.001?<?0.012; HCM P?=?0.037?<?0.040). Moreover, the Cox proportional hazard model suggested that both LGE status [Hazard ratio (HR)?=?2.62, P?=?0.017] and Gal-3 level (HR?=?1.16, P?=?0.013) were significant predictors of MACEs in DCM, while they did not appear to have significant prognostic values for HCM (P?=?0.06 and 0.64). Furthermore, the multivariate analysis only confirmed LGE as an independent element in predicting prognosis of DCM (HR?=?12.19, P?=?0.026). In conclusion, LGE status was an independent indicator of DCM prognosis, yet the insignificant role of LGE in HCM prognosis could be limited by sample size.     

斑点追踪技术评价肥厚型心肌病左心室肌扭转运动

目的 应用斑点追踪技术研究肥厚型心肌病的左心室肌的旋转运动及扭转特征.方法 病例组为24例非对称性肥厚型心肌病患者,其中室间隔和左心室前、侧壁增厚归为病例组1,室间隔中上部肥厚归为病例组2;正常对照组为48名健康志愿者.采用GE Vivid 7超声诊断仪,采集左心室短轴二尖瓣水平、乳头肌水平、心尖水平二维图像,脱机分析得到不同水平、不同节段的旋转角度、旋转速度及扭转角度,计算舒张早期解旋率.结果 病例组乳头肌水平旋转角度较正常对照组趋向于逆时针方向,且病例组2与正常对照组差异有统计学意义(P<0.05);二尖瓣水平和心尖水平旋转运动三组间差异无统计学意义(P>0.05).病例组1、病例组2与正常对照组左心室舒张早期解旋率分别为(0.22±0.11)%/ms、(0.23±0.08)%/ms、(0.43±0.19)%/ms,病例组1和病例组2均较正常对照组降低(P<0.05).结论 肥厚型心肌病不同的表现型其左心室扭转及旋转运动表现不同;应用斑点追踪技术可以准确地评价肥厚型心肌病患者的左心室扭转及旋转运动.     

应变率显像对肥厚型心肌病心肌收缩和舒张功能的研究

目的　通过应变率显像评价肥厚型心肌病患者肥厚心肌的局部收缩和舒张功能。方法　10例肥厚型心肌病患者(HCM)与 20例正常对照者,获取左室室间隔长轴方向基底段、中段和心尖段的心肌应变率曲线,及中段肥厚的室间隔三层心肌的应变率曲线,测定应变率数值 (SR),包括收缩期峰值SR、舒张早期峰值SR和舒张晚期峰值SR,测量左室射血分数(EF)和二尖瓣口血流的E、A峰值。结果　HCM组肥厚节段心肌收缩期和舒张期的SR均低于正常组相应节段的测值(P<0. 05)。HCM组肥厚节段内层、中层及外层心肌收缩期和舒张期的SR均低于正常组对应节段各层的相应测值(P<0. 05)。HCM组肥厚节段各层心肌收缩期和舒张期SR之间的差异无显著性意义。两组间的EF和E/A值差异无显著性意义。结论　肥厚型心肌病肥厚心肌的SR明显降低,其各层之间SR的差异无显著性意义。     

MR特征追踪技术定量评估肥厚型心肌病心肌应变

目的 探讨MR特征追踪技术（CMR-FT）定量分析肥厚型心肌病（HCM）左心室整体和局部心肌应变的临床价值。方法 收集HCM患者60例（HCM组）及健康志愿者10名（对照组）。所有受检者均接受心脏MR检查,扫描序列包括心室短轴、二腔心、四腔心层面快速平衡稳态进动序列（FIESTA）和延迟增强扫描（LGE）。HCM组按有无强化分为无强化亚组和有强化亚组。采用CMR-FT后处理软件测定心肌整体的径向应变峰值（GPSR）、环向应变峰值（GPSC）、纵向应变峰值（GPSL）以及心室不同部位（心尖部、心室中部和基底部）的径向、环向和纵向应变峰值（PSR、PSC和PSL）。结果 有强化亚组、无强化亚组和对照组的GPSR、GPSC和GPSL差异有统计学意义（P均<0.05）,呈增高趋势。除心尖部PSL 3组间差异无统计学意义外,有强化亚组、无强化亚组和对照组的PSR、PSC和PSL差异均有统计学意义（P均<0.05）,在心脏各部位均呈上升趋势。LVEF、SV与GPSR、GPSC、GPSL均呈正相关（P均<0.05）。GPSR、GPSC、GPSL诊断HCM的ROC曲线下面积分别为0.79、0.82、0.77（P均<0.05）,其中GPSC的曲线下面积最大。结论 CMR-FT技术能够早期敏感地发现HCM的心肌应变功能障碍,且纵向应变受损早于或重于环向应变及径向应变。     

CMR assessment and clinical outcomes of hypertrophic cardiomyopathy with or without ventricular remodeling in the end-stage phase

End-stage phase of hypertrophic cardiomyopathy (ES-HCM) is a recognized part of HCM disease spectrum. Information on cardiac magnetic resonance (CMR) studies for ES-HCM especially for those without ventricular remodeling has been limited. We aimed to evaluate the morpho-functional and tissue features of ES-HCM with or without ventricular remodeling and to explore CMR prognostic value in these patients. We analysed CMR scans of sixty-three ES-HCM patients and divided them into those with ventricular dilatation (D-ES, n?=?41) and those with normal ventricular size (N-ES, n?=?22). Cox proportional hazards models were used to assess the association between CMR parameters and outcomes. Patients in D-ES showed hypokinetic-dilated HCM phenotype, while patients in N-ES showed hypokinetic-restrictive HCM phenotype. LGE extent was significantly larger in D-ES (34.7%?±?15.4% vs. 22.8%?±?7.7%; P?<?0.01). Atrial fibrillation and edema of lower extremity were more common in N-ES (72.7 vs. 29.3% and 54.5 vs. 24.4%, respectively; P?<?0.05). Log-rank test found no significant difference between 2 groups in combined end point of cardiovascular events (χ²?=?0.66, P?=?0.418). In multivariate analysis, LGE (HR 1.57–1.83 per 10% LGE increase, P?<?0.01) and indexed left atrial volume (LAVI) (HR 1.14–1.21 per 20 mL/m² increase, P?<?0.05) remained independently associated with combined end point when adjusted by other risk factors. The CMR features of HCM in end-stage span between two extremes. LGE is more extensive in those with ventricular remodeling and LAVI is larger in those with normal ventricular size. Both LGE and LAVI are significant predictors of poor outcomes.     

肥厚型心肌病心电图特点与超声心动图临床分析

目的：探讨肥厚型心肌病心电图特点与超声心动图的关系，提高临床对该病的诊断意识。方法：对23例确诊为肥厚型心肌病的临床资料进行分析。结果：所有肥厚型心肌病病人的心电图均有ST-T的异常表现，8例间隔肥厚型心肌病表现为Ⅱ、Ⅲ、aVF病理性Q波及ST段抬高；6例心尖肥厚型心肌病表现为Ⅰ、aVL、V2-V6导联巨大倒置T波；9例普遍肥厚型心肌病表现为V4-V6、导联T波倒置或伴有Ⅱ、Ⅲ、aVF导联T波倒置，其改变范围小。结论：重视心电图的改变特点并与心脏超声相结合可以提高该病的诊断符合率。     

实时心肌造影评价肥厚型心肌病患者心内膜下及心外膜下心肌灌注

目的应用实时心肌超声造影分析肥厚型心肌病（HCM）患者心内膜下及心外膜下心肌灌注状况,及其与室壁肥厚程度的关系,以评价肥厚型心肌病患者心肌微循环障碍。方法HCM患者26例,正常对照组20例,实时心肌超声造影观察心尖四腔、两腔、左心长轴切面实时动态图像,应用时间～强度曲线分析造影图像。结果HCM患者左室肥厚节段及非肥厚心肌节段的心内膜下及心外膜下心肌的A及A×k值低于对照组（P〈0．05）,k值高于对照组（P〈0．001）。HCM患者左室肥厚节段心内膜下及心外膜下心肌的的A及A×k值低于非肥厚心肌节段（P〈0．05）,k值高于非肥厚心肌节段（P〈0．05）。HCM患者心内膜下A、及A×k值低于下心外膜下（P〈0．001）。HCM患者肥厚节段心内膜下及心外膜下心肌A×k值与肥厚节段室壁厚度均呈负相关（r=-0．785,P〈0．001;r=-0．461,P〈0．05）。结论HCM患者肥厚节段与非肥厚节段的心内膜下及心外膜下心肌均存在微循环障碍,且以心内膜下心肌微循环损伤更为显著,同时,随着室壁厚度的增加,心肌血流灌注显著减少。实时心肌超声造影是评价HCM患者心肌微循环障碍的有效方法。     

Extracellular volume fraction in dilated cardiomyopathy patients without obvious late gadolinium enhancement: comparison with healthy control subjects

To evaluate whether the extracellular volume fraction (ECV) measured using cardiac magnetic resonance (CMR) imaging can detect myocardial tissue changes in dilated cardiomyopathy (DCM) without late gadolinium enhancement (LGE). Forty-one DCM patients and 10 healthy volunteers underwent pre- and post-T1 mapping using a modified Look-Locker Inversion recovery sequence, LGE, and cine MRI on a 3-T CMR system. LGE-MR findings were used to divide DCM patients into two groups: Group A had no apparent LGE, and Group B had LGE apparent in at least one segment. The ECV of the left ventricle (LV) myocardium (16 segments) was calculated in the short-axis view as follows: ECV = [(ΔR1 of myocardium/ΔR1 of LV blood pool)] × (1 ? hematocrit), where R1 = 1/T1, ΔR1 = post-contrast R1 ? pre-contrast R1. The LV ejection fraction (LVEF) was obtained from cine MRI images. The mean myocardial ECV in LGE (?) segments in Group A + B was compared to that of controls. The mean myocardial ECV in Group A was compared to that of LGE (?) segments in Group B. The correlation between LV systolic function and the mean myocardial ECV of the whole myocardium was evaluated in all groups. Among the 41 DCM patients, 22 were in Group A, and 19 were in Group B. The mean ECV of DCM patents (n = 41, 568 segments, 30.7 % ± 5.9) was significantly higher (P < 0.001) than that of the control group (n = 10, 157 segments, 25.6 % ± 3.2). The ECV was inversely related to LVEF in Group A (r = ?0.551, P = 0.008), Group B (r = ?0.525, P = 0.021), and Group A + B (r = ?0.550, P < 0.001). The ECV measured by MRI could be a useful parameter in evaluating diffuse myocardial changes in DCM patients.