Physiological determinants of the variation in left ventricular mass from early adolescence to late adulthood in healthy subjects

BACKGROUND: The physiological determinants of left ventricular mass (LVM) measured by cardiac magnetic resonance (CMR) imaging are not well defined as prior investigators have studied either adults or adolescents in isolation or have not strictly excluded hypertension or accounted for the effects of exercise habits, haemodynamic, demographic, or body shape characteristics. METHODS: Ninety-seven healthy volunteers (11-81 years, 51 males) underwent CMR. All parameters [unstandardized and adjusted for body surface area (BSA)] were analysed according to gender and by adolescence versus adulthood (adolescents<20 years, adults>or=20 years). The influence of haemodynamic factors, exercise and demographic factors on LVM were determined with multivariate linear regression. RESULTS: Left ventricular mass rose during adolescence and declined in adulthood. LVM and LVMBSA were higher in males both in adults (LVM: 188+/-22 versus 140+/-21 g, P<0.001; LVMBSA: 94+/-11 versus 80+/-11 g m(-2), P<0.001) and in adolescents when adjusted for BSA (LVM: 128+/-29 versus 107+/-20 g, P=0.063; LVMBSA: 82+/-8 versus 71+/-10 g m(-2), P=0.025). In adults, systolic blood pressure (SBP) and self-reported physical activity increased while meridional and circumferential wall stress were constant with age. Multivariate regression analysis revealed age, gender and BSA as the major determinants of LVM (global R2=0.68). CONCLUSIONS: Normal LVM shows variation over a broad age range in both genders with a rise in adolescence and subsequent decline with increasing age in adulthood despite an increase in SBP and physical activity. BSA, age and gender were found to be major contributors to the variation in LVM in healthy adults, while haemodynamic factors, exercise and wall stress were not.     

二维及三维心血管MR特征追踪技术测量高血压患者左心室心肌形变北大核心CSCD

目的评价二维(2D)及三维(3D)心血管MR特征追踪(CMR-FT)技术评估高血压患者左心室心肌形变的可行性及其一致性。方法纳入60例高血压患者(高血压组)及60健康人(正常组)。基于2D和3D CMR-FT技术测量左心室应变参数、收缩期及舒张期应变率。采用组内相关系数(ICC)、Bland-Altman一致性检验及变异系数(CV)评估心肌形变参数测量的重复性;比较组间参数的差异。结果2D与3D CMR-FT观察者内及观察者间测量结果的一致性均极好(ICC:0.75~0.98,P均<0.05),离散程度多相对较小(CV≤14.54%);Bland-Altman一致性检验显示,心肌形变参数多位于95%的一致性界限范围内。2D CMR-FT所测高血压组整体纵向应变(GLS)、收缩期峰值径向应变率(PSSR R)及圆周应变率(PSSR C)、舒张期峰值径向/圆周/纵向应变率(PDSR R/C/L)均明显小于正常组(P均<0.05);3D CMR-FT所测高血压组GLS及PDSR R/C/L均明显小于正常组(P均<0.05)。结论2D和3D CMR-FT技术均可发现高血压患者心功能异常改变,且其心肌形变测值具有较高一致性。     

健康成人左心室重构与血脂比值的独立相关性北大核心CSCD

目的观察健康成人左心室重构与血脂比值的独立相关性。方法收集352名接受心脏MR(CMR)检查的健康体检者资料,测量其心脏周围脂肪组织(PAT)体积、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、每搏输出量(SV)、射血分数(EF)和舒张末期左心室心肌质量(LVM)等,计算左心室重构指数(LVRI),即LVM/LVEDV;同时检测其血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C),计算血脂比值TC/HDL-C、TG/HDL-C及LDL-C/HDL-C;观察LVRI与血脂比值的相关性。结果LVRI与TC/HDL-C、TG/HDL-C及LDL-C/HDL-C均呈低度正相关(r=0.414、0.441、0.407,P均<0.05)。分别以TC/HDL-C、TG/HDL-C及LDL-C/HDL-C为自变量,以LVRI为因变量,以校正后的年龄、性别、心率、空腹血糖、收缩压及体表面积各因素建立多元线性回归模型1,结果显示LVRI与TC/HDL-C、TG/HDL-C及LDL-C/HDL-C均呈正相关(β=0.175、0.161、0.181,P均<0.05);在此基础上加入校正后PAT体积建立模型2,结果显示LVRI与TC/HDL-C、TG/HDL-C及LDL-C/HDL-C均呈正相关(β=0.149、0.137、0.167,P均<0.05)。结论健康成人左心室重构与血脂比值呈独立正相关,提示临床需早期防控血脂异常。     

组织追踪MR技术评价正常人左室形变功能的临床研究

目的：采用心脏磁共振（cardiac magnetic resonance，CMR）电影序列的组织追踪技术探讨正常人左室应变。方法：随机入组2018年于复旦大学附属中山医院行CMR检查的健康志愿者39例，将影像学Dicom资料存盘后，应用CVI软件的组织追踪模块分析CMR电影序列图像，比较左室心肌形变指标基底段、中间段与心尖段的差别；内膜下与外膜下的差别；性别间、年龄分组间的差别。结果：39例健康志愿者左室内膜下、外膜下及整体心肌应变自基底段至心尖段递增；自心内膜下至心外膜下左室心肌应变递减，差异有统计学意义（P<0.05）；性别对左室应变无明显影响。结论：组织追踪MR可定量分析左室整体、节段与内膜下、外膜下心肌形变功能，为临床评价心脏功能提供新的依据。     

Determination of left ventricular long-axis orientation using MRI: changes during the respiratory and cardiac cycles in normal and diseased subjects

BACKGROUND: It has previously been shown that magnetic resonance imaging (MRI) can be used to accurately determine left ventricular (LV) long-axis orientation in healthy individuals. However, the inter- and intra-observer variability in patients with acute coronary syndrome (ACS) and chronic heart failure (CHF) has not been explored. Furthermore, the changes in LV long-axis orientation because of respiration and during the cardiac cycle remain to be determined. METHODS: LV long-axis orientation was determined by MRI in the frontal and transverse planes in 44 subjects with no cardiac disease, 20 ACS patients and 13 CHF patients. Changes in LV long-axis orientation because of respiration were assessed in a subset of 25 subjects. Changes during the cardiac cycle were assessed in six subjects from each subject group. Reproducibility was assessed by a re-examination of 17 subjects after 28 days. RESULTS: The inter- and intra-observer variability for LV long-axis orientation was low for all subject groups. The difference between the baseline and the 28 days examinations was -1.4+/-5.9 degrees and -0.8+/-4.4 degrees in the frontal and transverse planes, respectively. No significant change in LV long-axis orientation was found between end-expiration and end-inspiration (frontal plane, P=0.63 and transverse plane, P=0.42; n=25). No significant difference in change of the LV long-axis orientation during the cardiac cycle was found between the subject groups (frontal plane, chi-square 1.8, P=0.40 and transverse plane, chi-square 5.7, P=0.06). CONCLUSIONS: There is a low inter-and intra-observer variability and a high reproducibility for determining LV long-axis orientation in patients with no cardiac disease as well as in patients with ACS or CHF. There is no significant change in LV long-axis orientation due to respiration, and only small changes during the cardiac cycle in these groups.     

Vortex flow during early and late left ventricular filling in normal subjects: quantitative characterization using retrospectively-gated 4D flow cardiovascular magnetic resonance and three-dimensional vortex core analysis

Background

LV diastolic vortex formation has been suggested to critically contribute to efficient blood pumping function, while altered vortex formation has been associated with LV pathologies. Therefore, quantitative characterization of vortex flow might provide a novel objective tool for evaluating LV function. The objectives of this study were 1) assess feasibility of vortex flow analysis during both early and late diastolic filling in vivo in normal subjects using 4D Flow cardiovascular magnetic resonance (CMR) with retrospective cardiac gating and 3D vortex core analysis 2) establish normal quantitative parameters characterizing 3D LV vortex flow during both early and late ventricular filling in normal subjects.

Methods

With full ethical approval, twenty-four healthy volunteers (mean age: 20±10 years) underwent whole-heart 4D Flow CMR. The Lambda2-method was used to extract 3D LV vortex ring cores from the blood flow velocity field during early (E) and late (A) diastolic filling. The 3D location of the center of vortex ring core was characterized using cylindrical cardiac coordinates (Circumferential, Longitudinal (L), Radial (R)). Comparison between E and A filling was done with a paired T-test. The orientation of the vortex ring core was measured and the ring shape was quantified by the circularity index (CI). Finally, the Spearman’s correlation between the shapes of mitral inflow pattern and formed vortex ring cores was tested.

Results

Distinct E- and A-vortex ring cores were observed with centers of A-vortex rings significantly closer to the mitral valve annulus (E-vortex L=0.19±0.04 versus A-vortex L=0.15±0.05; p=0.0001), closer to the ventricle’s long-axis (E-vortex: R=0.27±0.07, A-vortex: R=0.20±0.09, p=0.048) and more elliptical in shape (E-vortex: CI=0.79±0.09, A-vortex: CI=0.57±0.06; <0.001) compared to E-vortex. The circumferential location and orientation relative to LV long-axis for both E- and A-vortex ring cores were similar. Good to strong correlation was found between vortex shape and mitral inflow shape through both the annulus (r=0.66) and leaflet tips (r=0.83).

Conclusions

Quantitative characterization and comparison of 3D vortex rings in LV inflow during both early and late diastolic phases is feasible in normal subjects using retrospectively-gated 4D Flow CMR, with distinct differences between early and late diastolic vortex rings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12968-014-0078-9) contains supplementary material, which is available to authorized users.     

Cardiovascular magnetic resonance parameters associated with early transplant-free survival in children with small left hearts following conversion from a univentricular to biventricular circulation

Background

We sought to identify cardiovascular magnetic resonance (CMR) parameters associated with successful univentricular to biventricular conversion in patients with small left hearts.

Methods

Patients with small left heart structures and a univentricular circulation who underwent CMR prior to biventricular conversion were retrospectively identified and divided into 2 anatomic groups: 1) borderline hypoplastic left heart structures (BHLHS), and 2) right-dominant atrioventricular canal (RDAVC). The primary outcome variable was transplant-free survival with a biventricular circulation.

Results

In the BHLHS group (n = 22), 16 patients (73%) survived with a biventricular circulation over a median follow-up of 40 months (4–84). Survival was associated with a larger CMR left ventricular (LV) end-diastolic volume (EDV) (p = 0.001), higher LV-to-right ventricle (RV) stroke volume ratio (p < 0.001), and higher mitral-to-tricuspid inflow ratio (p = 0.04). For predicting biventricular survival, the addition of CMR threshold values to echocardiographic LV EDV improved sensitivity from 75% to 93% while maintaining specificity at 100%. In the RDAVC group (n = 10), 9 patients (90%) survived with a biventricular circulation over a median follow-up of 29 months (3–51). The minimum CMR values were a LV EDV of 22 ml/m² and a LV-to-RV stroke volume ratio of 0.19.

Conclusions

In BHLHS patients, a larger LV EDV, LV-to-RV stroke volume ratio, and mitral-to-tricuspid inflow ratio were associated with successful biventricular conversion. The addition of CMR parameters to echocardiographic measurements improved the sensitivity for predicting successful conversion. In RDAVC patients, the high success rate precluded discriminant analysis, but a range of CMR parameters permitting biventricular conversion were identified.     

Advanced image fusion to overlay coronary sinus anatomy with real-time fluoroscopy to facilitate left ventricular lead implantation in CRT

Background: Failure rate for left ventricular (LV) lead implantation in cardiac resynchronization therapy (CRT) is up to 12%. The use of segmentation tools, advanced image registration software, and high‐fidelity images from computerized tomography (CT) and cardiac magnetic resonance (CMR) of the coronary sinus (CS) can guide LV lead implantation. We evaluated the feasibility of advanced image registration onto live fluoroscopic images to allow successful LV lead placement. Methods: Twelve patients (11 male, 59 ± 16.8 years) undergoing CRT had three‐dimensional (3D) whole‐heart imaging (six CT, six CMR). Eight patients had at least one previously failed LV lead implant. Using segmentation software, anatomical models of the cardiac chambers, CS, and its branches were overlaid onto the live fluoroscopy using a prototype version of the Philips EP Navigator software to guide lead implantation. Results: We achieved high‐fidelity segmentations of cardiac chambers, coronary vein anatomy, and accurate registration between the 3D anatomical models and the live fluoroscopy in all 12 patients confirmed by balloon occlusion angiography. The CS was cannulated successfully in every patient and in 11, an LV lead was implanted successfully. (One patient had no acceptable lead values due to extensive myocardial scar.) Conclusion: Using overlaid 3D segmentations of the CS and cardiac chambers, it is feasible to guide CRT implantation in real time by fusing advanced imaging and fluoroscopy. This enabled successful CRT in a group of patients with previously failed implants. This technology has the potential to facilitate CRT and improve implant success. (PACE 2011; 34:226–234)     

Cardiovascular magnetic resonance assessment of ventricular function and myocardial scarring before and early after repair of anomalous left coronary artery from the pulmonary artery

Background

In patients with anomalous left coronary artery from the pulmonary artery (ALCAPA) left ventricular (LV) dilatation and dysfunction evolves due to diminished myocardial perfusion caused by coronary steal phenomenon. Using late gadolinium enhanced cardiovascular magnetic resonance (LGE-CMR) imaging, myocardial scarring has been shown in ALCAPA patients late after repair, however the incidence of scarring before surgery and its impact on postoperative course after surgical repair remained unknown.

Methods

8 ALCAPA-patients (mean age 10.0 ± 5.8 months) underwent CMR before and early after (mean 4.9 ± 2.5 months) coronary reimplantation procedures. CMR included functional analysis and LGE for detection of myocardial scars.

Results

LV dilatation (mean LVEDVI 171 ± 94 ml/m²) and dysfunction (mean LV-EF 22 ± 10 %) was present in all patients and improved significantly after surgery (mean LVEDV 68 ± 42 ml/m², p = 0.02; mean LV-EF 58 ± 19 %, p < 0.001). Preoperative CMR revealed myocardial scarring in 2 of the 8 patients and did not predict postoperative course. At follow-up CMR, one LGE-positive patient showed delayed recovery of LV function while myocardial scarring was still present in both patients. In two patients new-onset transmural scarring was found, although functional recovery after operation was sufficient. One of them showed a stenosis of the left coronary artery and required resurgery.

Conclusions

Despite diminished myocardial perfusion and severely compromised LV function, myocardial scarring was preoperatively only infrequently present. Improvement of myocardial function was independent of new-onset scarring while the impact of preoperative scarring still needs to be defined.     

Left ventricular shape variation in asymptomatic populations: the multi-ethnic study of atherosclerosis

Background

Although left ventricular cardiac geometric indices such as size and sphericity characterize adverse remodeling and have prognostic value in symptomatic patients, little is known of shape distributions in subclinical populations. We sought to quantify shape variation across a large number of asymptomatic volunteers, and examine differences among sub-cohorts.

Methods

An atlas was constructed comprising 1,991 cardiovascular magnetic resonance (CMR) cases contributed from the Multi-Ethnic Study of Atherosclerosis baseline examination. A mathematical model describing regional wall motion and shape was used to establish a coordinate map registered to the cardiac anatomy. The model was automatically customized to left ventricular contours and anatomical landmarks, corrected for breath-hold mis-registration between image slices. Mathematical techniques were used to characterize global shape distributions, after removal of translations, rotations, and scale due to height. Differences were quantified among ethnicity, sex, smoking, hypertension and diabetes sub-cohorts.

Results

The atlas construction process yielded accurate representations of global shape (errors between manual and automatic surface points in 244 validation cases were less than the image pixel size). After correction for height, the dominant shape component was associated with heart size, explaining 32% of the total shape variance at end-diastole and 29% at end-systole. After size, the second dominant shape component was sphericity at end-diastole (13%), and concentricity at end-systole (10%). The resulting shape components distinguished differences due to ethnicity and risk factors with greater statistical power than traditional mass and volume indices.

Conclusions

We have quantified the dominant components of global shape variation in the adult asymptomatic population. The data and results are available at cardiacatlas.org. Shape distributions were principally explained by size, sphericity and concentricity, which are known correlates of adverse outcomes. Atlas-based global shape analysis provides a powerful method for quantifying left ventricular shape differences in asymptomatic populations.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00005487","term_id":"NCT00005487"}}NCT00005487     

Beneficial effects of beta‐blockers on left ventricular function and cellular energy reserve in patients with heart failure

Beta‐blockers have been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non‐invasively assess, by means of in vivo 31P‐magnetic resonance spectroscopy (31P‐MRS), the effects of beta‐blockers on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure. Ten heart failure patients on full medical therapy were beta‐blocked by either carvedilol or bisoprolol. Before and after 3 months of treatment, exercise testing, 2D echocardiography, MRS, New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate–pressure product and exercise metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P‐MRS. After beta‐blockade, NYHA class decreased (from 2.2 ± 0.54 to 1.9 ± 0.52, P = 0.05), whereas EF (from 33 ± 7 to 44 ± 6%, P = 0.0009) and METS (from 6.74 ± 2.12 to 8.03 ± 2.39, P = 0.01) increased. Accordingly, the mean cardiac PCr/ATP ratio increased by 33% (from 1.48 ± 0.22 to 1.81 ± 0.48, P = 0.03). Beta‐blockade‐induced symptomatic and functional improvement in patients with heart failure is associated to increased PCr/ATP ratio, indicating preservation of myocardial high‐energy phosphate levels.     

充血性心力衰竭患者血浆脑钠肽水平与左室质量比值的相关性研究

目的探讨充血性心力衰竭(CHF)患者血浆脑钠肽(BNP)、肿瘤坏死因子(TNF-α)、内皮素(ET)的水平及与左室质量比值(PLM)的相关性。方法用放射免疫法测定71例CHF患者(CHF组,心功能Ⅱ~Ⅳ级)及30例体检正常者(对照组)血浆BNP、TNF-α、ET的水平;超声心动图测定CHF组及对照组左室质量,并根据收缩压计算左室质量预计值,PLM=左室质量实测值/左室质量预计值×100%。结果CHF组的血浆BNP、TNF-α、ET水平及PLM显著高于对照组(P<0.001),且BNP、TNF-α、ET水平与PLM呈正相关,相关系数分别为r=0.79、P<0.01, r=0.60、P<0.05, r=0.56、P<0.05。结论CHF患者血浆BNP、TNF-α、ET水平明显增高,反映心室重构的PLM异常,BNP与PLM相关性最好。     

A disproportionate contribution of papillary muscles and trabeculations to total left ventricular mass makes choice of cardiovascular magnetic resonance analysis technique critical in Fabry disease

Background

Sphingolipid deposition in Fabry disease causes left ventricular (LV) hypertrophy, of which the accurate assessment is essential. Cardiovascular magnetic resonance (CMR) has been proposed as the gold standard. However, there is debate in the literature as to whether papillary muscles and trabeculations (P&T) should be included in LV mass (LVM).

Methods/results

We examined the accuracy of 2 CMR methods of assessing LVM and LV volumes, including (M_incP&T) or excluding (M_exP&T) P&T, in a cohort of Fabry disease subjects (n = 20) compared to a matched control group (n = 20). Significant differences between the two measurement methods were observed for LV end-diastolic volume, LV end-systolic volume, LVM, and LV ejection fraction (LVEF) in both groups. These differences were significantly greater in the Fabry group compared to controls, except for LVEF. P&T contributed to a greater percentage of LVM in Fabry subjects than controls (20 ± 1% vs 13 ± 2%, p = 0.01). In the control group, both volume-derived methods (M_incP&T or M_exP&T) provided accurate SV measurements compared with the internal reference of velocity-encoded aortic flow. In the Fabry group, inclusion of P&T (M_incP&T) resulted in good concordance with phase contrast flow imaging (difference between flow and volume techniques: 1 ± 3 ml, p = 0.7).

Conclusion

The volumetric contribution of P&T in Fabry disease is markedly increased relative to healthy controls. Failure to account for this results in significant underestimation of LVM and results in misclassification of a proportion of subjects.     

Evaluation of left ventricular dysfunction using multiphasic reconstructions of coronary multi-slice computed tomography data in patients with chronic ischemic heart disease: validation against cine magnetic resonance imaging

Purpose: Multi-slice computed tomography (MSCT) is an emerging technique for the angiographic assessment of coronary artery disease (CAD). The purpose of this work was to determine if multiphasic reconstructions of the same data used for the assessment of CAD could also be used for global functional evaluation of the left ventricle (LV). Materials and methods: Fifteen patients with chronic ischemic heart disease (CIHD) were imaged for CAD using a contrast-enhanced retrospective electrocardiographic-gated spiral technique on a MSCT scanner. The same data were reconstructed at both end-diastole and end-systole in order to measure left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), and ejection fraction (LVEF). The results were compared to values obtained using a cine true-fast imaging with steady-state precession technique on a magnetic resonance imaging (MRI) scanner. Interobserver variability in the measurement from MSCT images was also evaluated. Results: For LVEF, there was substantial agreement between MSCT and MRI (intraclass correlation coefficient of 0.825); the intermodality reproducibility for LVEF (5%) was within an acceptable clinical range. However, mean values of LVEDV and LVESV with MSCT compared to cine MRI (LVEDV: 262.0 ± 85.6 ml and 297.2 ± 98.8 ml, LVESV: 196.2 ± 75.6 ml and 218.6 ± 90.99 ml, respectively) were significantly less for both volumes (p < 0.015). Intermodality variabilities for these measurements were high (15 and 13% for LVEDV and LVESV, respectively). Readers' mean measurements of LVESV from MSCT images were significantly different (p = 0.003) resulting in differences in calculation of LVEF (p < 0.024). Still, interobserver variabilities for all values were acceptable (6, 8, and 5% for LVEDV, LVESV, and LVEF, respectively). Conclusion: Although values for LVEDV and LVESV were less with MSCT than with MRI, LVEF values were in agreement. This suggests that combined imaging of CAD and the evaluation of global LV dysfunction due to CIHD is feasible with the same MSCT acquisition.     

Comparison of cardiovascular magnetic resonance characteristics and clinical consequences in children and adolescents with isolated left ventricular non-compaction with and without late gadolinium enhancement

Background

Although cardiovascular magnetic resonance (CMR) is showing increasingly diagnostic potential in left ventricular non-compaction (LVNC), relatively little research relevant to CMR is conducted in children with LVNC. This study was performed to characterize and compare CMR features and clinical outcomes in children with LVNC with and without late gadolinium enhancement (LGE).

Methods

A cohort of 40 consecutive children (age, 13.7 ± 3.3 years; 29 boys and 11 girls) with isolated LVNC underwent a baseline CMR scan with subsequent clinical follow-up. Short-axis cine images were used to calculate left ventricular (LV) ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), myocardial mass, ratio of non-compacted-to-compacted myocardial thickness (NC/C ratio), and number of non-compacted segments. The LGE images were analyzed to assess visually presence and patterns of LGE. The primary end point was a composite of cardiac death and heart transplantation.

Results

The LGE was present in 10 (25 %) children, and 46 (27 %) segments were involved, including 23 non-compacted segments and 23 normal segments. Compared with LGE- cohort, LGE+ cohort had significantly lower LVEF (23.8 ± 10.7 % vs. 42.9 ± 16.7 %, p < 0.001) and greater LVEDV (169.2 ± 65.1 vs. 118.2 ± 48.9 mL/m², p = 0.010), LVESV (131.3 ± 55.5 vs. 73.3 ± 46.7 mL/m², p = 0.002), and sphericity indices (0.75 ± 0.19 vs. 0.60 ± 0.20, p = 0.045). There were no differences in terms of number and distribution of non-compacted segments, NC/C ratio, and myocardial mass index between LGE+ and LGE- cohort. In the LGE+ cohort, adverse events occurred in 6 patients compared to 2 events in the LGE- cohort. Kaplan-Meier analysis showed a significant difference in outcome between LGE+ and LGE- cohort for cardiac death and heart transplantation (p = 0.011).

Conclusions

The LGE was present in up to one-fourth of children with LVNC, and the LGE+ children exhibited a more maladaptive LV remodeling and a higher incidence of cardiovascular death and heart transplantation.     

The role of multimodality imaging in the diagnosis of left ventricular noncompaction

Left ventricular noncompaction (LVNC) is a heterogeneous entity and, in reality, a likely spectrum of disease which is clinically associated with arrhythmia, thromboembolic complications and sudden cardiac death. With the emergence of cardiac MRI (cMRI), the phenotype is increasingly more prevalent, resulting in clinical uncertainty regarding prognosis and management. The currently accepted hypothesis suggests an early embryonic arrest of the normal, sequential myocardial compaction process. LVNC is observed in isolation or in association with congenital heart disease, neuromuscular disease or a vast array of genetic cardiomyopathies. Definition of the entity varies among international society guidelines with differences both within and between imaging modalities, predominantly echocardiography and cMRI. Long-term prognostic data are emerging but due to the intrinsic variability in reported prevalence, selection bias and lack of pathological to prognostic correlation, there are many uncertainties regarding clinical management. This review seeks to clarify the role of multimodality imaging in diagnosis and management of the disease. We discuss the sensitivity and specificity of the current diagnostic criteria, as well as the nuances in diagnosis using the available imaging modalities.     

An approach to the three-dimensional display of left ventricular function and viability using MRI

Cardiac MRI was performed in human volunteers to determine the magnitude of the misregistration (MSR) of cardiac landmarks due to variability in the diaphragm position for repeated breath-holds. Seven normal volunteers underwent MR imaging of the left ventricle (LV) to evaluate the magnitude of the endocardial centroid MSR. The MSR for a mid-ventricle short-axis image was 3.01 ± 1.68 mm through-plane and 4.16 ± 1.62 mm in-plane. A second order polynomial fit through the LV centroid coordinates minimized the in-plane component of the MSR error. Short-axis cine images, corrected for MSR, provided high-resolution 2D data from which an accurate anatomical model of the LV was generated. Anatomical landmarks were used to register parametric maps of myocardial perfusion and viability to the three-dimensional (3D) model, with the corresponding parameters displayed as color-encoded values on the endo- and epicardial surfaces of the LV. Registration of regional wall motion, perfusion and viability to the 3D model was performed for three patients with a history of cardiovascular disease. The proposed 3D reconstruction technique allows visualization in 3D of the LV anatomy, in combination with parametric mapping of its functional status.     

二维斑点追踪超声心动图评估冠状动脉病变对收缩早期左心室心肌运动的影响

目的观察采用二维斑点追踪超声心动图(2D-STE)评估冠状动脉病变对收缩早期左心室心肌运动影响的可行性。方法将179例接受冠状动脉造影检查的可疑冠心病患者的左心室心肌节段按供血冠状动脉狭窄程度分为对照组(无狭窄)、轻度组(狭窄程度≤50%)、中度组(50%<狭窄程度<75%)和重度组(狭窄程度≥75%)。采用2D-STE分析各组左心室心肌节段纵向预拉伸峰值应变(LPSS)和圆周预拉伸峰值应变(CPSS)的差异。结果左心室各层心肌LPSS和CPSS峰值于收缩早期出现,轻度组均最高(P均<0.05),中度组最低(P均<0.05);冠状动脉轻度狭窄时收缩早期左心室心肌拉伸运动加强,随着冠状动脉病变加重而逐渐减弱。结论2D-STE可无创评估冠状动脉病变对收缩早期左心室心肌运动的影响。     

Six-months of recombinant human GH therapy in patients with ischemic cardiac failure

Growth hormone therapy in patients with idiopathic dilated cardiomyopathy and ischemic cardiac failure has revealed varying effects on systolic function, probably related to the response in serum insulin-like growth factor I (IGF-I) levels. As diastolic function has not been studied thoroughly, we studied the effects of 6 months of recombinant human growth hormone (rh GH) treatment on systolic and diastolic function in patients with ischemic cardiac failure, using cardiovascular magnetic resonance (MR) imaging. Nineteen patients with ischemic cardiac failure (left ventricular ejection fraction (LVEF), <40%) were studied in a randomized trial. Nine patients received 6 months treatment with growth hormone (2 IU/day). Systolic and diastolic function were assessed at baseline and after 26 weeks by cardiovascular MR imaging. No differences were found in systolic and diastolic function between rh GH treated patients and controls. No change was observed in left ventricular mass index (LVMI), end-diastolic volume, end-systolic-volume and ejection fraction. The treated patients showed no clinical improvement. Six months of treatment with growth hormone therapy in ischemic cardiac failure has no favorable effects on LVMI, on systolic and diastolic function.