Single-beat real-time three-dimensional echocardiographic automated contour detection for quantification of left ventricular volumes and systolic function

To assess the feasibility and accuracy in measuring left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) with Siemens single-beat real-time 3D transthoracic echocardiography. The LV volumes and EF were measured in 3D datasets acquired by six imaging modes (time-1-harmonic (T1H), time-1-fundamental, time-2-harmonic, time-2-fundamental, space-1-harmonic (S1H), and space-1-fundamental) in 41 patients using the automated contouring algorithm and compared with manually corrected 3DE QLAB measurements. The main determinates of the temporal and spatial resolutions of 3D datasets acquired were the fundamental and harmonic modes. Consequently, the S1H mode had the lowest volume rate and highest spatial resolution. Compared with the 3DE QLAB analysis, the S1H mode resulted in the best LV volumes and EF estimates in all patients (0 ± 10 % for EF, ?7 ± 44 ml for EDV, ?7 ± 39 ml for ESV) and in the 10 patients with correct LV contour tracking according to a visual assessment from the multiplanar reconstruction views in all six modes (0 ± 9 % for EF, ?3 ± 23 ml for EDV, ?2 ± 14 ml for ESV). The T1H mode was the best alternative. Overall 28 patients (68 %) could be analysed automatically and satisfyingly with the S1H and T1H modes: 0 ± 8 % (EF), 0 ± 27 ml (EDV) and ?1 ± 16 ml (ESV). The accuracy of the Siemens automated RT-3D algorithm in measuring LV volumes and EF is significantly influenced by the different imaging modes. The S1H mode may be the preferred 3D acquisition mode, supplemented by the T1H mode in enlarged LVs that do not fit in the S1H acquisition sector.     

Semiautomatic three-dimensional CT ventricular volumetry in patients with congenital heart disease: agreement between two methods with different user interaction

To assess agreement between two semi-automatic, three-dimensional (3D) computed tomography (CT) ventricular volumetry methods with different user interactions in patients with congenital heart disease. In 30 patients with congenital heart disease (median age 8 years, range 5 days–33 years; 20 men), dual-source, multi-section, electrocardiography-synchronized cardiac CT was obtained at the end-systolic (n = 22) and/or end-diastolic (n = 28) phase. Nineteen left ventricle end-systolic (LV ESV), 28 left ventricle end-diastolic (LV EDV), 22 right ventricle end-systolic (RV ESV), and 28 right ventricle end-diastolic volumes (RV EDV) were successfully calculated using two semi-automatic, 3D segmentation methods with different user interactions (high in method 1, low in method 2). The calculated ventricular volumes of the two methods were compared and correlated. A P value <0.05 was considered statistically significant. LV ESV (35.95 ± 23.49 ml), LV EDV (88.76 ± 61.83 ml), and RV ESV (46.87 ± 47.39 ml) measured by method 2 were slightly but significantly smaller than those measured by method 1 (41.25 ± 26.94 ml, 92.20 ± 62.69 ml, 53.61 ± 50.08 ml for LV ESV, LV EDV, and RV ESV, respectively; P ≤ 0.02). In contrast, no statistically significant difference in RV EDV (122.57 ± 88.57 ml in method 1, 123.83 ± 89.89 ml in method 2; P = 0.36) was found between the two methods. All ventricular volumes showed very high correlation (R = 0.978, 0.993, 0.985, 0.997 for LV ESV, LV EDV, RV ESV, and RV EDV, respectively; P < 0.001) between the two methods. In patients with congenital heart disease, 3D CT ventricular volumetry shows good agreement and high correlation between the two methods, but method 2 tends to slightly underestimate LV ESV, LV EDV, and RV ESV.     

Quantification of left ventricular volume and global function using a fast automated segmentation tool: validation in a clinical setting

Real-time 3D echocardiography (RT3DE) has already been shown to be an accurate tool for left ventricular (LV) volume assessment. However, LV border detection in RT3DE remains a time-consuming task jeopardizing the application of this modality in routine practice. We have recently developed a 3D automated segmentation framework (BEAS) able to capture the LV morphology in real-time. The goal of this study was to assess the accuracy of this approach in extracting volumetric parameters in a clinical setting. 24 RT3DE exams were acquired in a group of healthy volunteers (# = 5) and diseased patients (# = 19), with LV volume/function within a range typically measured in a clinical setting. End-diastolic and end-systolic volumes (EDV, ESV) were manually contoured by 3 expert sonographers from which the stroke volume and ejection fraction (SV, EF) were calculated. The values extracted with BEAS were compared to the average of the 3 experts measurements using correlation and Bland–Altman statistics. Linear regression analysis showed a strong correlation between the automated algorithm and the reference values (R = 0.963, 0.947, 0.944 and 0.853 for EDV, ESV, SV and EF respectively). Bland–Altman analysis revealed a bias (limits of agreement) of 2.59 (?25.39, 30.57) ml, ?2.11 (?24.91, 20.69) ml, 4.70 (12.93, 22.34) ml and 3.45 (?8.96, 15.87) %, for EDV, ESV, SV and EF respectively. Total analysis time using BEAS was 30.7 ± 7.5 s. BEAS allows for a fast and accurate quantification of 3D cardiac volumes and global function with minimal user input. It may therefore contribute to the integration of 3D echocardiography in routine clinical practice.     

Balloon pulmonary angioplasty improves interventricular dyssynchrony in patients with inoperable chronic thromboembolic pulmonary hypertension: a cardiac MR imaging study

To use cardiac magnetic resonance imaging (MRI) to investigate the effect of balloon pulmonary angioplasty (BPA) on interventricular dyssynchrony and its associations with ventricular interaction, which impairs LV function in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). This prospective observational study was approved by our institutional review board. Cardiac MRI and right heart catheterization were conducted before BPA sessions and at the follow up after BPA in 20 patients with CTEPH. We measured right ventricular (RV) and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) using MRI. For the LV and RV free walls, the time to peak (T_peak) of circumferential strain was calculated as a parameter for interventricular dyssynchrony. Following BPA, the RV-EDV and -ESV were significantly decreased, and the RVEF was significantly increased. Conversely, BPA led to significantly increased LV EDV and SV without changing LVESV. The left-to-right free wall delay (L–R delay) in T_peak strain decreased from 105?±?44 ms to 47?±?67 ms (p?<?0.001). Increased LV EDV (r?=?0.65, p?<?0.01), SV (r?=?0.74, p?<?0.001) and 6-minute walk distance (6MWD) (r?=?0.54, p?<?0.05) were correlated to the reduction in L–R delay. In patients with inoperable CPEPH, BPA improved interventricular dyssynchrony, which was strongly associated with increased SV and 6MWD. The assessment of interventricular dyssynchrony using cardiac MRI has an important role in evaluating ventricular interaction, which reduces LVSV and exercise tolerance.     

Improving the reproducibility of MR-derived left ventricular volume and function measurements with a semi-automatic threshold-based segmentation algorithm

To validate a novel semi-automatic segmentation algorithm for MR-derived volume and function measurements by comparing it with the standard method of manual contour tracing. The new algorithms excludes papillary muscles and trabeculae from the blood pool, while the manual approach includes these objects in the blood pool. An epicardial contour served as input for both methods. Multiphase 2D steady-state free precession short axis images were acquired in 12 subjects with normal heart function and in a dynamic anthropomorphic heart phantom on a 1.5T MR system. In the heart phantom, manually and semi-automatically measured cardiac parameters were compared to the true end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF). In the subjects, the semi-automatic method was compared to manual contouring in terms of difference in measured EDV, ESV, EF and myocardial volume (MV). For all measures, intra- and inter-observer agreement was determined. In the heart phantom, EDV and ESV were underestimated for both the semi-automatic. As the papillary muscles were excluded from the blood pool with the semi-automatic method, EDV and ESV were approximately 20 ml lower in the patients, whereas EF was approximately 16 % higher. Intra- and inter-observer agreement was overall improved with the semi-automatic method compared to the manual method. Correlation between manual and semi-automatic measurements was high (EDV: R = 0.99, ESV: R = 0.96; EF: R = 0.80, MV: R = 0.99). The semi-automatic method could exclude endoluminal muscular structures from the blood volume with significantly improved intra- and inter-observer variabilities in cardiac function measurements compared to the conventional, manual method, which includes endoluminal structures in the blood volume.     

Sources of variation and bias in assessing left ventricular volumes and dyssynchrony using three-dimensional echocardiography

Study aim To explore various sources of variability in the measurement of LV volumes and dyssynchrony by 3D echocardiography (3DE). Methods We studied 100 patients (58?±?18?years, 51 men) to assess the impact of: (1) manual editing; (2) 3D data set temporal resolution; (3) LV 16- or 17-segmentation model; (4) software sensitivity for automated endocardial surface detection; and (5) image quality, on the measurement of LV end-diastolic (EDV) and end-systolic (ESV) volumes, sphericity indices (EDSI, ESSI), ejection fraction (EF) and dyssynchrony (SDI). Two- and 4-beat LV full-volume data sets were analyzed and compared. Cardiac magnetic resonance (CMR) was used as reference in 26 patients. Results Manual editing of endocardial surface improved the agreement of LV volumes with CMR, but increased SDI (SDI17: 5.6?±?0.5% vs. 4.3?±?0.3%; P?相似文献   

The cardiac MRI substudy to ongoing telmisartan alone and in combination with ramipril global endpoint trial/telmisartan randomized assessment study in ACE-intolerant subjects with cardiovascular disease: analysis protocol and baseline characteristics

Background  The ONTARGET and TRANSCEND clinical trials were designed to investigate the cardioprotective effects of telmisartan 80 mg and ramipril 10 mg, alone and in combination, in patients at high risk of cardiovascular disease. Cardiac MRI enables investigation of mechanistic effects of these agents on cardiac structural and functional variables. Here, we report the design, analysis protocol, reproducibility and relevant quality control procedures, and baseline patient characteristics of the ONTARGET/TRANSCEND cardiac MRI substudy. MRI was undertaken in 330 subjects enrolled in ONTARGET, and 38 subjects in TRANSCEND, across eight centers in six countries. Analyses were performed by two independent analysts using guide-point modeling. Cases with discrepancies in LV mass (LVM) of >5% were independently reanalyzed. Cases with discrepancies in end-diastolic volume (EDV) of >5%, or end-systolic volume (ESV) of >12%, were then reconciled by consensus. Results  Baseline characteristics were broadly similar to the main ONTARGET/TRANSCEND trials, except for a higher frequency of coronary artery disease and Asian ethnicity in the substudy. Reproducibility of MRI analyses (mean ± SD) were 2.8 ± 3.7 ml in EDV, −0.3 ± 3.6 ml in ESV, 3.1 ± 3.3 ml in SV, 1.1 ± 1.8% in EF, and 0.4 ± 4.5 g in LVM. Subgroup analyses revealed increased ESV and LVM, and reduced EF, in subjects with a history of either coronary artery disease or myocardial infarction. Conclusions  The ONTARGET/TRANSCEND cardiac MRI substudy protocol provides for a reliable assessment of the effects of telmisartan and ramipril, alone and in combination, on cardiac structural and functional parameters over a 2-year follow-up period. For the ONTARGET Investigators.     

Pressure overloaded right ventricles: a multicenter study on the importance of trabeculae in RV function measured by CMR

Cardiac magnetic resonance (CMR) imaging is the preferred method to measure right ventricular (RV) volumes and ejection fraction (RVEF). This study aimed to determine the impact of excluding trabeculae and papillary muscles on RV volumes and function in patients with RV pressure and/or volume overload and healthy controls and its reproducibility using semi-automatic software. Eighty patients (pulmonary hypertension, transposition of the great arteries after arterial switch operation and after atrial switch procedure and repaired Tetralogy of Fallot) and 20 controls underwent short-axis multislice cine CMR. End diastolic volume (EDV), end systolic volume (ESV), RV mass and RVEF were measured using 2 methods. First, manual contour tracing of RV endo- and epi-cardial borders was performed. Thereafter, trabeculae were excluded from the RV blood volume using semi-automatic pixel-intensity based software. Both methods were compared using a Student T test and 25 datasets were re-analyzed for reproducibility. Exclusion of trabeculae resulted in significantly decreased EDV; ranging from ?5.7 ± 1.7 ml/m² in controls to ?29.2 ± 6.6 ml/m² in patients after atrial switch procedure. RVEF significantly increased in all groups, ranging from an absolute increase of 3.4 ± 0.8 % in healthy controls to 10.1 ± 2.3 % in patients after atrial switch procedure. Interobserver agreement of method 2 was equal to method 1 for RVEDV, RVESV and RVEF and superior for RV mass. In patients with overloaded RVs exclusion of trabeculae from the blood volume results in a significant change in RV volumes, RVEF and RV mass. Exclusion of trabeculae is highly reproducible when semi-automatic pixel-intensity based software is used.     

Comparison of effects of losartan and metoprolol on left ventricular and aortic function at rest and during exercise in chronic aortic regurgitation

Aortic regurgitation (AR) increases the hemodynamic load on both the left ventricle (LV) and the aorta. Vasodilators and beta-blockers both reduce systemic blood pressure, but their relative effects on the LV and aortic function and aortic regurgitant fraction in chronic AR are uncertain. We aimed to compare short-term effects of losartan and metoprolol on LV and aortic function in asymptomatic patients with chronic moderate to severe AR, both at rest and during exercise, using cardiac magnetic resonance (CMR) imaging. 17 chronic AR patients were randomized to 4–6 weeks losartan followed by metoprolol, or vice versa, in a cross-over design. Aortic regurgitant fraction, aortic distensibility, pulse wave velocity and LV function were assessed at rest and after moderate exercise stress (29?±?7 W, heart rate increase 25?±?6 bpm) using CMR. Chronic AR patients on metoprolol had a significantly lower mean heart rate, cardiac power index and rate-pressure product, than on losartan (all p?<?0.01). However, aortic regurgitant fraction was greater on metoprolol compared to losartan (by 7?±?11%, p?=?0.02). Metoprolol was also associated with a greater reduction in aortic distensibility during exercise than losartan (??2.4?±?1.5?×?10^?3 vs ??1.7?±?2.1?×?10^?3 mmHg^?1 respectively, p?=?0.04). End-diastolic volume index was higher on metoprolol than losartan at exercise (difference 6.6?±?7.8 ml/m², p?<?0.01), as was end-systolic volume index (difference 4.0?±?5.2 ml/m², p?<?0.01). Losartan and metoprolol have significantly different short-term effects on aortic regurgitation and LV and aortic function in chronic AR. Further research is required to determine the long-term clinical significance of these changes.     

Rb-82 PET/CT left ventricular mass-to-volume ratios

Left ventricular (LV) mass:volume ratios indexed to body size (Mi/Vi) provide risk stratification for cardiac events. We sought to determine whether Rb-82 PET mass and volume indices are similar to MRI normal values for low likelihood subjects, and whether abnormal indices are related to abnormal myocardial blood flow (MBF). Data were analyzed retrospectively for 194 patients referred for rest/stress Rb-82 PET. LV EF, volume and mass values were calculated and mass:volume ratios were indexed to patients’ height and weight. MBF was computed from the first pass dynamic component of PET data. 53 patients at low likelihood of CAD had PET Mi/Vi?=?1.35?±?0.27, consistent with the MRI literature range of 1.0–1.5. Compared to patients with normal indexed volume (Vi), patients with abnormally high Vi had lower rest MBF (0.56?±?0.24 vs 0.93?±?0.57 ml/g/min, p?=?0.0001), and lower stress MBF (0.97?±?0.52 vs. 1.83?±?0.96 ml/g/min, p?<?0.0001). Stress EF?<?50% predicted abnormal Vi with 90% accuracy. Patients with Mi/Vi?<?1.0 had abnormally low rest EF (45?±?16% vs. 60?±?15%, p?<?0.0001) and low rest MBF (0.58?±?0.25 vs. 0.96?±?0.59 ml/g/min, p?<?0.0001). In our study population, abnormal LV volume and mass correlated with lower rest and stress MBF and EF, suggesting that the pathophysiologic explanation of these patients’ increased risk is more extensive obstructive CAD.     

Measurement of Left Ventricular Volumes and Ejection Fraction in Patients with Regional Wall Motion Abnormalities Using an Automated 3D Quantification Algorithm

Accurate and rapid left ventricular (LV) ejection fraction (EF) measurement is crucial for patients with wall motion abnormalities (WMAs). Conventional 2D echocardiographic imaging has limitations. The recently developed software HeartModel (HM, Philips Healthcare, Andover, MA, USA) has shown promise in automated 3D quantification. However, the accuracy and detailed features of HM in measurements of LV volume and EF in patients with regional WMAs have not been carefully investigated. In the present study, echocardiographic imaging (EPIQ, X5-1, Philips Healthcare) was performed in 72 patients with WMAs. The LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF were measured by HM in three modes: without editing and with global and regional endocardial border editing (Auto 3D-NE, Auto 3D-GE and Auto 3D-RE, respectively). The conventional 2D Simpson's biplane method and manual 3D quantification (QLAB-3DQA software, Philips Healthcare), as the standard method, were used for comparison. Among the three HM modalities, Auto 3D-RE exhibited the best correlation with manual 3D in assessing EDV, ESV and EF (r?=?0.88, 0.93 and 0.91, respectively), although it took slightly longer (67.3 ± 13.0 s). Auto 3D-RE also exhibited a small degree of bias for the measurements (EDV: 11.7mL, ESV: 8.45mL, EF: –1.57%) and narrow limits of agreement. Heterogeneity of LV wall motion was defined to indicate the dispersion degree of WMAs. It associated with the difference in EF measurement between Auto 3D-RE and manual 3D (p?=?0.014, hazard ratio?=?5.19). In patients with WMAs, HM with regional contour editing enables accurate and efficient evaluation of LV volume and EF.     

实时三维超声心动图对比评价正常右心室及左心室功能

目的 观察利用实时三维超声心动图(RT-3DE)评估、比较成年人正常心脏左右心室的可行性,并探讨左右心室之间的关系.方法 应用RT-3DE全容积成像采集58名心脏正常成年人的心脏三维数据,在TomTec工作站中分析获得右心室舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)和射血分数(EF);在Qlab工作站中分析获得左心室舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)和射血分数(EF).结果 右心室EDV[(85.84±20.82)ml]、ESV[(41.87士10.48)ml]分别大于左心室EDV[(69.37士17.83)ml]、ESV[(26.46±8.26) ml](P均＜0.001),而右心室EF[(50.94士5.57)％]小于左心室EF[(61.97±6.48)％,P＜0.001].左心室SV[(42.91±11.72) ml]与右心室SV[(43.96±12.15) ml]差异无统计学意义(P=0.273).左右心室的对应参数均有相关性.结论 RT-3DE是评估左右心室容积和功能的可行方法,且其相应参数在左右心室间是相关的.     

Quantification of left ventricular volumes and ejection fraction from gated 99mTc‐MIBI SPECT: MRI validation of the exini heart software package

The aim of the study was to validate the accuracy of the exini heart software (exini ) package in assessing left ventricular end‐diastolic/systolic volumes (EDV, ESV) and ejection fraction (LVEF) from gated ^99mTc‐MIBI single‐photon emission tomography (SPECT). Cardiac magnetic resonance imaging (cMRI) was used as reference. Furthermore, effects of perfusion defects and image quality in SPECT on correlation between gated SPECT and magnetic resonance imaging were investigated. Methods: Seventy patients were examined using gated SPECT (rest study, eight gates per cardiac cycle). EDV, ESV and LVEF were calculated from gated SPECT using exini . Directly before or after SPECT, cMRI (20 gates cardiac per cycle) was performed. EDV, ESV and LVEF were calculated using Simpson’s rule. Perfusion defects were quantified using the summed‐rest‐score (SRS). Total number of myocardial counts were used to rate image quality. Results: Correlation between results of gated SPECT and cMRI was high for EDV (R = 0·89) and ESV (R = 0·94) and good for LVEF (R = 0·78). ESV (exini 54 ± 31 ml versus cMRI 57 ± 34 ml) and LVEF (exini 62·9 ± 11·7% versus cMRI 60·6 ± 13·9%) did not differ significantly whereas exini overestimated EDV significantly compared with cMRI (exini 144 ± 41 ml versus cMRI 137 ± 36 ml; P<0·005). No correlation was found between absolute differences of the results given by gated SPECT and cMRI and SRS or total myocardial counts (R < 0·18). Conclusion: End‐diastolic volume, ESV and LVEF calculated from gated SPECT using exini agree with cMRI over a wide range of values. Correlation between both the methods was good for EDV and ESV, and acceptable for LVEF. No relevant influence of image quality or SRS on the accuracy of exini results was found.     

Less pronounced reverse left ventricular remodeling in patients with bicuspid aortic stenosis treated with transcatheter aortic valve replacement compared to tricuspid aortic stenosis

To compare reverse left ventricular (LV) remodeling after transcatheter aortic valve replacement (TAVR) between patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). We retrospectively reviewed data of patients with at least two serial echocardiographic follow-ups (1, 3, 6 months and 1 year) post-TAVR. A total of 116 patients were identified. BAV morphology was documented in 67 patients. LV mass index (LVMi) at baseline was not significantly different between the TAV and BAV group (178.0?±?6.9 vs. 166.3?±?6.4 g/m², P?=?0.14). Reverse LV remodeling was observed in both BAV and TAV patients, but the reduction of LVMi from baseline was significantly more pronounced in TAV patients compared with BAV patients from 6 months post-TAVR (??56.3?±?8.1 vs. ??30.0?±?4.7 g/m², P?<?0.01 at 6-month follow-up; ??60.6?±?7.6 vs. ??37.9?±?6.2 g/m², P?=?0.02 at 1-year follow-up). EDV value changes during follow-up were similar between patient with TAV and BAV. There were no significant differences in the proportions of patients with more than mild PVL or new permanent pacemaker between TAV and BAV morphology throughout the follow-up. Patients with bicuspid morphology might experience less pronounced reverse LV remodeling post-TAVR than patients with tricuspid morphology.     

MRI-derived left ventricular function parameters and mass in healthy young adults: Relation with gender and body size

Purpose: To obtain normal values of left ventricular (LV) end-diastolic volume (EDV), stroke volume (SV), cardiac output (CO) and LV mass, in relation to gender, weight (W), length (L) and body surface area (BSA). Methods: Sixty-one healthy volunteers (32 male, 22.4 ± 2.2?years) were examined, weight was 70.9 ± 12.2?kg, length was 1.78 ± 0.09?m, BSA was 1.88 ± 0.19 m². Segmented k-space breathhold cine MRI was used to obtain a stack of parallel short-axis images, from which LV volumes and end-diastolic mass were derived by slice summation. Four different body size indices were studied: W, L, L² and BSA. Results: After indexing for L, L² and BSA, the gender differences in all LV parameters are still persisting. After indexing for W, gender differences persist for EDV and EDM, but are no longer observed for SV and CO. Separate regression analyses for males and females were performed. EDV, SV, CO and EDM correlated significantly with each body size index, both in males and in females. L or BSA were in general better predictors for LV parameters than W. Linear regression equations of EDV (ml) vs. L(m) were for males: EDV = 275 × L ? 359 and for females: EDV = 190 × L ? 215. Equations of SV(ml) vs. L were for males: SV = 186 × L ? 237 and for females: SV = 118 × L ? 121. Equations of LV mass(g) vs. L were for males: Mass = 175 × L ? 179 and for females: Mass = 65.8 × L ? 10.9. Conclusion: Most gender differences in LV parameters remain even after correction for body size indices. Normal reference values for LV parameters are given in relation to body size indices, by calculating regression coefficients separately for males and females. These normal values serve to obtain more accurate reference values for a patient with given gender, weight and length, and thus to improve the differentiation between normal and abnormal LV parameters.     

Systolic heart failure and cardiac resynchronization therapy: a focus on diastole

Conflicting data exist about the effects of cardiac resynchronization therapy (CRT) on diastolic function (DF). Aim of the study was to assess if and how CRT affects DF in systolic heart failure patients. We also investigated potential relations between CRT-induced left ventricular changes and the composite clinical endpoint of progressive heart failure and cardiac death over 3 years follow-up. 119 CRT patients underwent clinical evaluation and echocardiography before CRT and 4 months later. DF was quantified by transmitral velocities [E/A waves, deceleration time (DT), E/DT], early diastolic mitral annulus velocity (E′), E/E′ ratio and 2-D speckle tracking strain rate during isovolumetric relaxation (IVR, SRivr). End-diastolic pressure–volume relationship (EDPVR) was also assessed noninvasively using a single-beat method. Overall stiffness was quantified by ventricular stiffness (K_lv) normalized to end-diastolic volume (EDV). New York Heart Association class improved at 4 months (from 2.7 ± 0.7 to 1.9 ± 0.6, p < 0.001) as did ventricular filling (E/DT from 0.48 ± 0.29 to 0.39 ± 0.31 cm/s², p = 0.01). In contrast, relaxation (E′, SRivr) and filling pressures (E/E′, E/SRivr) did not change. Slope of EDPVR did not change with CRT. Such finding, together with an unmodified Klv/EDV and a 7 ± 18 % reduction in EDV (p = 0.001), suggested reverse remodelling towards a smaller equilibrium volume. Finally, end-systolic LV volume decreased from 147 ± 59 to 125 ± 52 ml and ejection fraction increased from 0.26 ± 0.07 to 0.32 ± 0.09 (both p < 0.001). Using a Cox regression model we found that only changes (Δ) in diastolic, but not systolic indexes, correlated with the composite clinical endpoint, with increments in ΔEDV20 and ΔE/DT, single or combined, greatly increasing risk of heart failure and/or cardiac death (p = 0.003). Ventricular reverse remodelling, together with improvement in ventricular filling, rather than improvements of systolic function, predict clinical prognosis long-term post-CRT.     

[68Ga]-Albumin-PET in the Monitoring of Left Ventricular Function in Murine Models of Ischemic and Dilated Cardiomyopathy: Comparison with Cardiac MRI

Purpose

The purpose of this study is to evaluate left ventricular functional parameters in healthy mice and in different murine models of cardiomyopathy with the novel blood pool (BP) positron emission tomography (PET) tracer [⁶⁸Ga]-albumin.

Procedures

ECG-gated microPET examinations were obtained in healthy mice, and mice with dilative (DCM) and ischemic cardiomyopathy (ICM) using the novel BP tracer [⁶⁸Ga]-albumin (Alb_BP), as well as [¹⁸F]-FDG microPET. Cine-magnetic resonance imaging (MRI) examination performed on a clinical 1.5-T MRI provided the reference standard measurements.

Results

When considering the combined group of healthy controls, DCM and ICM Alb_BP-PET significantly overestimated the magnitudes of EDV (Alb_BP, 181?±?86 μl; cine-MRI, 125?±?80 μl; P?<?0.001) and ESV (Alb_BP, 136?±?92 μl; cine-MRI, 96?±?77 μl; P?<?0.001), whereas the EF (Alb_BP, 31?±?16 %; cine-MRI, 33?±?21 %; P?=?0.910) matched closely to cine-MRI results, as did findings with [¹⁸F]-FDG. High correlations were found between the measured cardiac parameters (EDV: R?=?0.978, ESV: R?=?0.989, and LVEF: R?=?0.992).

Conclusions

Measuring left ventricular function in mice with [⁶⁸Ga]-albumin BP PET is feasible and showed a high correlation compared to cine-MRI, which was used as a reference standard.     

Comprehensive echocardiographic assessment of biventricular function in the rabbit,animal model in cardiovascular research: feasibility and normal values

Quantification of cardiac structure and function is central in cardiovascular research. Rabbits are valuable research models of cardiovascular human disease; however, there is little normal data available. The aim of this study was to investigate feasibility and provide normal values for comprehensive echocardiographic assessment of biventricular function in rabbits. New Zealand white rabbits underwent trans-thoracic echocardiography using a general electric (GE) Vivid 7/E9 system with a 10 MHz transducer, under light sedation, to evaluate biventricular function and dimensions. Images for two-dimensional, M-mode, tissue Doppler imaging (TDI) and speckle-tracking strain echocardiography were acquired and analysed. 55 male rabbits (sized matched with a newborn human baby) were studied, mean weight was 2.9?±?0.23 kg. Adequate images were obtained in 90% for the left ventricle (LV) and 80% for the right ventricle (RV). Two-dimensional speckle-tracking strain was feasible in 60%. Average heart rate was 248?±?36 beats per minute; LV ejection faction 72?±?8.0; RV fractional area change 45.9?±?9.0%; RV myocardial performance index 0.39?±?0.35; tricuspid annular planar systolic excursion 0.60?±?0.24 cm. LV TDI parameters were S’ 8.6?±?3.1 cm/s; E’ 12.0?±?4.46 cm/s. RV TDI parameters were S’ 10.49?±?3.18; E’ 14.95?±?4.64 cm/s. LV and RV global peak systolic longitudinal strain were ?17?±?5 and ?22?±?8%, respectively. Comprehensive investigation of biventricular dimensions and function by echocardiography is feasible in the rabbit. Apical views and strain imaging have lower feasibility. Normal values of LV and RV functional parameters are with comparable values to human children. Animal cardiovascular research is key to develop new goals in clinical practice.     

Cardiovascular magnetic resonance in pregnancy: Insights from the cardiac hemodynamic imaging and remodeling in pregnancy (CHIRP) study

Background

Cardiovascular disease in pregnancy is the leading cause of maternal mortality in North America. Although transthoracic echocardiography (TTE) is the most widely used imaging modality for the assessment of cardiovascular function during pregnancy, little is known on the role of cardiovascular magnetic resonance (CMR). The objective of the Cardiac Hemodynamic Imaging and Remodeling in Pregnancy (CHIRP) study was to compare TTE and CMR in the non-invasive assessment of maternal cardiac remodeling during the peripartum period.

Methods

Between 2010–2012, healthy pregnant women aged 18 to 35 years were prospectively enrolled. All women underwent TTE and CMR during the third trimester and at least 3 months postpartum (surrogate for non-pregnant state).

Results

The study population included a total of 34 women (mean age 29?±?3 years). During the third trimester, TTE and CMR demonstrated an increase in left ventricular end-diastolic volume from 95?±?11 mL to 115?±?14 mL and 98?±?6 mL to 125?±?5 mL, respectively (p?<?0.05). By TTE and CMR, there was also an increase in left ventricular (LV) mass during pregnancy from 111?±?10 g to 163?±?11 g and 121?±?5 g to 179?±?5 g, respectively (p?<?0.05). Although there was good correlation between both imaging modalities for LV mass, stroke volume, and cardiac output, the values were consistently underestimated by TTE.

Conclusion

This CMR study provides reference values for cardiac indices during normal pregnancy and the postpartum state.     

磁共振在单心室心功能检测中的应用

目的利用磁共振成像（MRI）对53例单心室进行心功能检测研究,测得数值与心血管造影（CAG）结果作对照。方法53例单心室,男31例,女22例,平均年龄（4.49&#177;3.95）岁;术前43例,术后10例;分别通过核磁共振的电影序列扫描和CAG计算单心室舒张末、收缩末容量,心每搏量和射血分数,利用均数及t检验进行数据统计分析。结果53例单心室MR心功能测量值：舒张末容量均值（101.61&#177;33.61）ml/m^2,收缩末容量均值（40.31&#177;16.56）ml/m^2,每搏量均值为（62.59&#177;22.66）ml/m^2,射血分数为（61.23&#177;8.45）%;CAG测得单心室舒张末容量均值（137.59&#177;53.59）ml/m^2,收缩末容量均值（61.81&#177;22.13）ml/m^2,每搏量均值为（76.05&#177;35.46）ml/m^2,射血分数均值为（53.61&#177;9.68）%,经统计学分析,两组参数间差异无统计学意义。结论利用MR对单心室的心功能检测是目前非创伤性检查及术后随访中最为可靠的方法。