Assessment of right ventricular volumes and function using cardiovascular magnetic resonance cine imaging after atrial redirection surgery for complete transposition of the great arteries

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for measurement of right ventricular (RV) volumes and function. To date, no study has compared methods of data acquisition and analysis by CMR for adults with a systemic RV. Our objective was to evaluate RV size and function using axial and short axis views in adults post atrial switch (Mustard) surgery. A total of 34 adults (20 male, mean age at CMR 32 ± 6 years) were identified at our centre. Volumes, RV end-diastolic (EDV) and end-systolic (ESV) were measured in short axis and axial orientations by two independent experienced readers, blinded to clinical and CMR data. Intra and interobserver measurements in each view were compared using Bland–Altman plots and intraclass correlation coefficients (ICC). Although mean volumes were larger in the axial as compared with the short axis view [RVEDV 247 ± 67 vs. 233 ± 54 ml (p = 0.002) and RVESV 148 ± 54 vs. 136 ± 50 ml (p = 0.001)], mean RV ejection fractions (EF) were similar [41 ± 9 % vs. 43 ± 12 % (p = 0.13)]. Bland–Altman plots demonstrated better agreement for axial measures of RVEDV and right ventricular ejection fraction (RVEF) within and between observers. Similarly, ICC values were stronger for axial as compared with short axis volumes and function—intraobserver RVEDV 0.99 (0.98–0.99) versus 0.96 (0.92–0.98) and RVEF 0.96 (0.93–0.98) versus 0.90 (0.82–0.95); interobserver RVEDV 0.97 (0.94–0.98) versus 0.90 (0.73–0.95) and RVEF 0.85 (0.53–0.94) versus 0.82 (0.67–0.90). Axially derived measurements of RV volumes and function have better agreement and reproducibility as compared with short axis values; whereas axial volumes tend to be larger, RVEF is not significantly different between the two methods.     

Impact of right ventricular endocardial trabeculae on volumes and function assessed by CMR in patients with tetralogy of Fallot

The objective of this study was to assess the impact of right ventricular (RV) trabeculae and papillary muscles on measured volumes and function assessed by cardiovascular magnetic resonance imaging in patients with repaired tetralogy of Fallot. Sixty-five patients with repaired tetralogy of Fallot underwent routine cardiovascular magnetic resonance imaging. Endocardial and epicardial contours were drawn manually and included trabeculae and papillary muscles in the blood volume. Semi-automatic threshold-based segmentation software excluded these structures. Both methods were compared in terms of end-diastolic, end-systolic and stroke volume, ejection fraction and mass. Observer agreement was determined for all measures. Exclusion of trabeculae and papillary muscle in the RV blood volume decreased measured RV end-diastolic volume by 15 % (from 140 ± 35 to 120 ± 32 ml/m²) compared to inclusion, end-systolic volume by 21 % (from 74 ± 23 to 59 ± 20 ml/m²), stroke volume by 9 % (from 66 ± 16 to 60 ± 16 ml/m²) and relatively increased ejection fraction by 7 % (from 48 ± 7 to 51 ± 8 %) and end-diastolic mass by 79 % (from 28 ± 7 to 51 ± 10 g/m²), p < .01. Excluding trabeculae and papillary muscle resulted in an improved interobserver agreement of RV mass compared to including these structures (coefficient of agreement of 87 versus 78 %, p < .01). Trabeculae and papillary muscle significantly affect measured RV volumes, function and mass. Semi-automatic threshold-based segmentation software can reliably exclude trabeculae and papillary muscles from the RV blood volume.     

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.     

The importance of trabecular hypertrophy in right ventricular adaptation to chronic pressure overload

To assess the contribution of right ventricular (RV) trabeculae and papillary muscles (TPM) to RV mass and volumes in controls and patients with pulmonary arterial hypertension (PAH). Furthermore, to evaluate whether TPM shows a similar response as the RV free wall (RVFW) to changes in pulmonary artery pressure (PAP) during follow-up. 50 patients underwent cardiac magnetic resonance (CMR) and right heart catheterization at baseline and after one-year follow-up. Furthermore 20 controls underwent CMR. RV masses were assessed with and without TPM. TPM constituted a larger proportion of total RV mass and RV end-diastolic volume (RVEDV) in PAH than in controls (Mass: 35 ± 7 vs. 25 ± 5 %; p < 0.001; RVEDV: 17 ± 6 vs. 12 ± 6 %; p = 0.003). TPM mass was related to the RVFW mass in patients (baseline: R = 0.65; p < 0.001; follow-up: R = 0.80; p < 0.001) and controls (R = 0.76; p < 0.001). In PAH and controls, exclusion of TPM from the assessment resulted in altered RV mass, volumes and function than when included (all p < 0.01). Changes in RV TPM mass (β = 0.44; p = 0.004) but not the changes in RVFW mass (p = 0.095) were independently related to changes in PAP during follow-up. RV TPM showed a larger contribution to total RV mass in PAH (~35 %) compared to controls (~25 %). Inclusion of TPM in the analyses significantly influenced the magnitude of the RV volumes and mass. Furthermore, TPM mass was stronger related to changes in PAP than RVFW mass. Our results implicate that TPM are important contributors to RV adaptation during pressure overload and cannot be neglected from the RV assessment.     

实时三维超声心动图在三尖瓣下移畸形矫治术后右室重构评估中的应用

目的：探讨实时三维超声心动图（three-dimensional echocardiography,3DEcho）在三尖瓣下移畸形（Ebstein anomaly,EA）解剖矫治术后右室重构评估中的应用。 方法：回顾性分析2015年10月至2022年08月期间在中国医学科学院阜外医院住院行外科矫治术治疗的22例EA患者临床资料、3DEcho及心脏磁共振（cardiac magnetic resonance,CMR）指标。 结果：患者中位年龄30.7（14.1, 38.4）岁,中位随访时间22.9（6.5,35.6）月。3DEcho与CMR两种检查方法在基线右室舒张末容积指数（indexed right ventricular end-diastolic volume, RVEDVi）指标测值呈高度正相关(r = 0.908, P = 0.012);基线右室射血分数（right ventricular ejection fraction, RVEF）(r = 0.621, P = 0.002)、术后RVEF (r = 0.567, P = 0.009) ,两者测值均呈中度正相关,有统计学意义。术后与术前基线状态相比较,三尖瓣反流程度减轻【术后反流程度≥中度者3例（13.6%）vs.术前≥中度者20例（90.9%）,P<0.01】,RVEDVi较术前减小（98.4±54.8 vs. 188.5±114.5 ml/m2, P<0.01）,差异有统计学意义;术后整组RVEF变化无统计学意义（术后 41.2±7.9% vs. 术前44.6±6.7%, P=0.215）。 结论：3DEcho可准确评估EA患者右室容积及功能,并在术后随访评估右室重构中发挥重要作用。     

Dobutamine-induced increase of right ventricular contractility without increased stroke volume in adolescent patients with transposition of the great arteries: Evaluation with magnetic resonance imaging

Objective: Prognosis in patients with surgically corrected (Senning or Mustard) transposition of the great arteries (TGA) depends mainly on right ventricular (RV) function and RV functional reserve. We examined the role of dobutamine stress in the early detection of RV dysfunction in asymptomatic or slightly symptomatic patients with TGA using magnetic resonance imaging (MRI). Design and patients: Twelve asymptomatic or slightly symptomatic patients with chronic RV pressure overload, surgically corrected (Mustard or Senning) TGA (age 22.8 (±3.4) years; New York Heart Association (NYHA) class I/II) and nine age matched healthy volunteers (age 27.3 (±4.4) years) were included. MRI was applied both at baseline and during dobutamine stress (start dose 5 μg/kg/min to maximum dose 15 μg/kg/min) to determine RV and left ventricular (LV) stroke volumes (SV) and ejection fraction (EF). Results: At baseline only RVEF was significantly higher in controls than in patients (71 (±9) vs. 57 (±10)%, p < 0.001), other RV parameters were not significantly different between the two examined groups: RVSV (86 (±21) vs. 72 (±27) ml, p = ns), RV end-diastolic volume (EDV) (123 (±37) vs. 123 (±33) ml, p = ns), and heart rate (61 (±10) vs. 69 (±14) bpm, p = ns), respectively. During dobutamine stress RVEF increased significantly both in controls and patients (20 (±16) vs. 17 (±18)%, p < 0.01 and p < 0.02 vs. rest, respectively), but stress RVEF was significantly higher in controls than in patients (85 (±3) vs. 66 (±7)%, p < 0.0001). RVSV increased significantly in controls (22 (±19)%, p < 0.02), and there was no significant increase in RVSV in patients (?10 (±28)%, p = ns). The controls showed no change in RVEDV (2 (±17)%, p = ns), but in patients a significant decrease in RVEDV (?24 (±15)%, p < 0.001) was observed. Maximal heart rate was significantly higher in patients than in controls (122 (±20) vs. 101 (±14) bpm, p < 0.02). Conclusion: In asymptomatic or slightly symptomatic patients with surgically corrected TGA dobutamine had a positive inotropic effect on RV, but the increased contractility was not accompanied by an appropriate increase in SV. Our data suggest inadequate RV filling in this category of patients, possibly due to rigid atrial baffles and compromised atrial function or decreased compliance due to RV hypertrophy.     

Right ventricular peak systolic longitudinal strain is a sensitive marker for right ventricular deterioration in adult patients with tetralogy of Fallot

The aim of this study was to evaluate the feasibility of right ventricular (RV) longitudinal peak systolic strain (LPSS) assessment for the follow-up of adult patients with corrected tetralogy of Fallot (TOF). Adult patients (n = 18) with corrected TOF underwent echocardiography and CMR twice with a time interval of 4.2 ± 1.7 years. RV performance was derived from CMR, and included RV volumes and ejection fraction (EF). LPSS was calculated globally (GLPSS) and in the RV free wall (LPSS FW), with echocardiographic speckle-tracking strain-analysis. Baseline (G)LPSS values were compared between patients and healthy controls; the relation between (G)LPSS and CMR parameters was evaluated and the changes in (G)LPSS and CMR parameters during follow-up were compared. GLPSS and LPSS FW were significantly reduced in patients as compared to controls (−14.9 ± 0.7% vs. −21.6 ± 0.9% and −15.5 ± 0.9% vs. −22.7 ± 1.5%, P < 0.01). Moderate agreement between LPSS and CMR parameters was observed. RV EF remained unchanged during follow-up, whereas GLPSS and LPSS FW demonstrated a significant reduction. RVEF showed a 1% increase, whereas GLPSS decreased by 14%, and LPSS FW by 27%. RV LPSS is reduced in TOF patients as compared to controls; during follow-up RV EF remained unchanged whereas LPSS decreased suggesting that RV LPSS may be a sensitive marker to detect early deterioration in RV performance.     

Evaluation of knowledge-based reconstruction for magnetic resonance volumetry of the right ventricle after arterial switch operation for dextro-transposition of the great arteries

Right ventricular (RV) volume and function evaluation is essential in the follow-up of patients after arterial switch operation (ASO) for dextro-transposition of the great arteries (d-TGA). Cardiac magnetic resonance (CMR) imaging using the Simpson’s method is the gold-standard for measuring these parameters. However, this method can be challenging and time-consuming, especially in congenital heart disease. Knowledge-based reconstruction (KBR) is an alternative method to derive volumes from CMR datasets. It is based on the identification of a finite number of anatomical RV landmarks in various planes, followed by computer-based reconstruction of the endocardial contours by matching these landmarks with a reference library of representative RV shapes. The purpose of this study was to evaluate the feasibility, accuracy, reproducibility and labor intensity of KBR for RV volumetry in patients after ASO for d-TGA. The CMR datasets of 17 children and adolescents (males 11, median age 15) were studied for RV volumetry using both KBR and Simpson’s method. The intraobserver, interobserver and intermethod variabilities were assessed using Bland–Altman analyses. Good correlation between KBR and Simpson’s method was noted. Intraobserver and interobserver variability for KBR showed excellent agreement. Volume and function assessment using KBR was faster when compared with the Simpson’s method (5.1?±?0.6 vs. 6.7?±?0.9 min, p?<?0.001). KBR is a feasible, accurate, reproducible and fast method for measuring RV volumes and function derived from CMR in patients after ASO for d-TGA.     

Correlation between right ventricular T<Subscript>1</Subscript> mapping and right ventricular dysfunction in non-ischemic cardiomyopathy

Right ventricular (RV) fibrosis is increasingly recognized as the underlying pathological substrate in a variety of clinical conditions. We sought to employ cardiac magnetic resonance (CMR) techniques of strain imaging and longitudinal relaxation time (T₁) mapping to better examine the relationship between RV function and structure. Our aim was to initially evaluate the feasibility of these techniques to evaluate the right ventricle. We then sought to explore the relationship between RV function and underlying fibrosis, along with examining the evolution of RV remodeling according to the amount of baseline fibrosis. Echocardiography was performed in 102 subjects with non-ischemic cardiomyopathy. Right ventricular parameters were assessed including: fractional area change (FAC) and longitudinal strain. The same cohort underwent CMR. Post-contrast T₁ mapping was performed as a marker of fibrosis with a Look-Locker technique using inversion recovery imaging. Mid-ventricular post-contrast T₁ values of the RV free wall, RV septum and lateral LV were calculated using prototype analysis software. Biventricular volumetric data including ejection fraction was measured by CMR using a cine short axis stack. CMR strain analysis was also performed to assess 2D RV longitudinal and radial strain. Simultaneous biochemical and anthropometric data were recorded. Subjects were followed over a median time of 29 months (IQR 20–37 months) with echocardiography to evaluate temporal change in RV FAC according to baseline post-contrast T₁ values. Longitudinal data analysis was performed to adjust for patient loss during follow-up. Subjects (62% men, 51?±?15 years) had mild to moderately impaired global RV systolic function (RVEF?=?39?±?15%; RVEDV?=?187?±?69 ml; RVESV?=?119?±?68 ml) and moderate left ventricular dysfunction at baseline (LVEF 30?±?17%). Good correlation was observed between mean LV and RV post-contrast T₁ values (r?=?0.652, p?<?0.001), with similar post-contrast T₁ values maintained in both the RV free wall and septum (r?=?0.761, p?<?0.001). CMR RVEF demonstrated a proportional correlation with echocardiographic measures of RV longitudinal function and CMR RV strain (longitudinal r?=??0.449, p?=?0.001; radial r?=??0.549, p?<?0.001). RVEF was related to RV post-contrast T₁ values, particularly in those with RV dysfunction (free wall T₁ r?=?0.259 p?=?0.027; septal T₁ r?=?0.421 p?<?0.001). RV strain was also related to RV post-contrast T₁ values (r?=??0.417, p?=?0.002). Linear regression analysis demonstrated strain and post-contrast T1 values to be independently associated with RVEF. Subjects with severe RV dysfunction (CMR RVEF <25%) demonstrated lower RV CMR strain (longitudinal p?=?0.018; radial p?<?0.001), RV T₁ values (free wall p?=?0.013; septum <0.001) and RV longitudinal echocardiography parameters despite no difference in afterload. During follow-up, those with RV free wall post-contrast T₁ values?≥?350 ms demonstrated ongoing improvement in FAC (Δ6%), whilst values <350 ms were associated with deterioration in RV function (ΔFAC?=??5%) (p?=?0.026). CMR provides a comprehensive method by which to evaluate right ventricular function. Post-contrast T₁ mapping and CMR strain imaging are technically feasible and provide incremental information regarding global RV function and structure. The proportional relationship between RV function and post-contrast T₁ values supports that myocardial fibrosis is a causative factor of RV dysfunction in NICM, irrespective of RV afterload. This same structural milieu also appears integral to the propensity for both positive and negative RV remodeling long-term, suggestive that this is also determined by the degree of underlying RV fibrosis.     

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.     

Assessment of right ventricular function with 320-slice volume cardiac CT: comparison with cardiac magnetic resonance imaging

To evaluate the accuracy and feasibility of right ventricular function parameters measurement using 320-slice volume cardiac CT. Retrospective analysis of 50 consecutive patients (23 men, 27 women) with suspected pulmonary diseases was performed in electrocardiogram (ECG)-gated cardiac CT and cardiac magnetic resonance (CMR). Parameters including right ventricular end-diastolic volume (RVEDV), right ventricular end- systolic volume (RVESV), right ventricular stroke volume (RVSV), right ventricular cardiac output (RVCO), and right ventricular ejection fraction (RVEF) were semi-automatically and separately calculated from both CT and CMR data. Significant difference between measurements was measured by paired t test and two-variable linear regression analysis with Pearson’s correlation coefficient. Bland–Altman analysis was performed in each pair of parameters. There was little variability between the measurements by the two observers (kappa = 0.895–0.980, P < 0.05). There was good correlation between all parameters obtained by CT and CMR (P < 0.001): RVEDV (108.5 ± 21.9 ml, 113.5 ± 24.8 ml, r = 0.944), RVESV (69.8 ± 33.4 ml, 73.2 ± 35.4 ml, r = 0.972), RVSV (39.0 ± 13.2 ml, 40.2 ± 13.3 ml, r = 0.977), RVCO (2.6 ± 0.7 l, 2.6 ± 0.7 l. r = 0.958), RVEF (38.8 ± 19.1 %, 39.1 ± 19.3 %, r = 0.990), and there was no significant difference between CT and CMR measurements in RVEF (n = 50, t = ?0.677, P > 0.05). 320-slice volume cardiac CT is an accurate non-invasive technique to evaluate RV function.     

Diffuse fibrosis is common in the left,but not in the right ventricle in patients with transposition of the great arteries late after atrial switch operation

In adult patients with transposition of the great arteries (TGA) late after atrial switch operation (AtSO), each of the ventricles is faced with a profoundly different pressure regimen from the one they are meant to support in normal conditions. The extent of diffuse fibrosis of the right ventricle (RV) and left ventricle (LV) in these patients remains incompletely investigated. Aim of this study was to quantify the degree of fibrosis of the unloaded LV and of the overloaded RV by determining the myocardial extracellular volume (ECV) with non-invasive techniques as T1 mapping. We determined ECV by cardiac magnetic resonance (CMR) in 10 patients (36.8?±?5.3 years old) with TGA late after AtSO, without relevant pulmonary stenosis, by acquiring T1-maps of the myocardium before and 10 min after injection of Gadolinium-based contrast agent. ECV of the inferior wall (36% (33–41%)) and of the lateral wall (37% (35–39%)) of the LV was significantly increased compared to the ECV of the RV (27% (25–29%)), in both comparisons P?<?0.0001. Long-time LV unloading following atrial switch procedures leads to severe myocardial fibrosis of the subpulmonary LV. T1 mapping CMR might be useful for selection of patients with atrial switch operation, in whom reestablishment of the LV as a systemic ventricle by staged arterial switch operation is planned. However larger studies and newer higher resolution methods for T1-mapping are needed to determine the role of ECV in the decision of a surgical intervention in this kind of population.     

Reproducibility of peak filling and peak emptying rate determined by cardiovascular magnetic resonance imaging for assessment of biventricular systolic and diastolic dysfunction in patients with pulmonary arterial hypertension

Right ventricular (RV) and left ventricular (LV) diastolic stiffness may be independent contributors to disease progression in pulmonary arterial hypertension (PAH). The aims of this study are to assess reproducibility of peak emptying rate (PER) and early diastolic peak filling rate (PFR) for both the RV and the LV in PAH and study their relationship to stroke volume (SV). Triple weekly repetition of 20 (totalling 60) cardiovascular magnetic resonance (CMR) scans, were done on 10 patients with PAH and 10 healthy controls. RV and LV volumes were measured over the full cardiac cycle. PER and PFR were calculated as the first derivative of the time–volume relationship in both the RV and the LV and indexed to body surface area. Reproducibility and the relation to SV were studied in a mixed model. PFR was lower in PAH in both the RV (PAH?=?170 mL/m²/s, controls?=?236 mL/m²/s [p?<?0.01]) and in the LV (PAH?=?209 mL/m²/s, controls?=?311 mL/m²/s [p?<?0.01]). PERs were not significantly different between patients and controls. Reproducibility of PER and PFR was high. A trial targeting normalization of PFR requires a total sample size of <?20. PER and PFR in both ventricles were strongly associated with stroke volume (all four: p?<?0.01). Biventricular diastolic dysfunctions are strongly associated with stroke volume, and CMR can quantify them with high reproducibility, enabling small sample sizes for trials of therapies targeting diastolic dysfunction to increase survival.     

实时三维超声心动图观察右心室收缩功能：动物实验与临床研究

目的 应用实时三维超声心动图右心室功能4D RV-Function(4D-RVF)分析法评价正常人及房间隔缺损患者右心室收缩功能.方法 ①对10只离体新鲜猪心行实时三维容积成像(RT-3DE),分别用4D-RVF和心尖长轴8平面法(AL 8-plane)分析软件测量其右心室容积,将所测值再分别与实测值比较.②对93例正常人(NOR)和15例房间隔缺损(atrial septal defect,ASD)患者行实时三维全容积成像,应用4D RV-Function分析软件测量右心室舒张末期容积(RV-EDV)、收缩末期容积(RVESV),每搏输出量(RVSV)及射血分数(RVEF).结果 ①离体猪心4D-RVF法所测值较心尖长轴8平面法所测值与实测值更接近.相关性更好,相关系数分别为r1=0.93,r2=0.82.② 4D-RVF法测量正常组(NOR)的右心室参数各指标:RVEDV为(90.57±28.27)m1,RVESV为(38.32±14.18)ml,RVSV为(52.25±16.86)ml,RVEF 为(57.96±6.85)%.③ASD患者右心室收缩功能减低.结论 实时三维超声心动图右心室功能(4D-RVF)分析法可准确评价右心室收缩功能.     

Impact of surgical pulmonary valve replacement on ventricular mechanics in children with repaired tetralogy of Fallot

Impaired ventricular myocardial mechanics are observed in patients with repaired tetralogy of Fallot (rTOF). Effects of pulmonary valve replacement (PVR) on ventricular remodeling are controversial. The objective was to assess the impact of surgical PVR on ventricular mechanics in pediatric patients after rTOF. Speckle-tracking analysis was performed in 50 rTOF children, aged 12.6?±?3.3 years, pre-operatively and 14.5?±?2.2 months post-PVR. Early post-operative studies 2.2?±?0.6 months post-PVR were performed in 28 patients. Cardiac magnetic resonance (CMR) pre- and post-PVR was collected. Mid-term post-PVR right ventricular (RV) longitudinal strain increased above pre-operative strain (?19.2?±?2.7 to ?22.0?±?3.0%, p?<?0.001) with increases observed in individual RV segments. Left ventricular (LV) strain did not differ at medium-term follow-up. LV and RV longitudinal strain was reduced early post-operatively, followed by recovery of biventricular systolic strain by mid-term follow-up. CMR RV end-diastolic indexed volumes correlated with RV strain pre-operatively (r?=?0.432, p?=?0.005) and at mid-term follow-up (r?=?0.532, p?=?0.001). Volume-loaded RVs had reduced early RV basal longitudinal strain compared to pressure-loading conditions. Reversed basal counterclockwise rotation was associated with lower mid-term global LV and basal RV strain compared to patients with normal rotation. An increase in mid-term global and regional RV strain beyond pre-operative values suggests positive RV remodeling and adaptation occurs in children post-PVR. Patients with larger pre-operative RV volumes had lower RV strain post-operatively. The impact of LV rotation on RV mechanics highlights the presence of ventriculo-ventricular interactions. These findings have important clinical implications in pediatric rTOF patients towards identifying pre-operative factors that predict RV post-operative remodeling.     

Regional contribution to ventricular stroke volume is affected on the left side,but not on the right in patients with pulmonary hypertension

To develop more sensitive measures of impaired cardiac function in patients with pulmonary hypertension (PH), since detection of impaired right ventricular (RV) function is important in these patients. With the hypothesis that a change in septal function in patients with PH is associated with altered longitudinal and lateral function of both ventricles, as a compensatory mechanism, we quantified the contributions of these parameters to stroke volume (SV) in both ventricles using cardiac magnetic resonance (CMR). Seventeen patients (10 females) evaluated for PH underwent right heart catheterization (RHC) and CMR. CMR from 33 healthy adults (13 females) were used as controls. Left ventricular (LV) atrioventricular plane displacement (AVPD) and corresponding longitudinal contribution to LVSV was lower in patients (10.8?±?3.2 mm and 51?±?12?%) compared to controls (16.6?±?1.9 mm and 59?±?9?%, p?<?0.0001 and p?<?0.01, respectively). This decrease did not differ in patient with ejection fraction (EF) >50?% and <50?% (p?=?0.5) and was compensated for by increased LV lateral contribution to LVSV in patients (49?±?13?% vs. 37?±?7?%, p?=?0.001). Septal motion contributed less to LVSV in patients (5?±?8?%) compared to controls (8?±?4?%, p?=?0.05). RV AVPD was lower in patients (12.0?±?3.6 mm vs. 21.8?±?2.2 mm, p?<?0.0001) but longitudinal and lateral contribution to RVSV did not differ between patients (78?±?17?% and 29?±?16?%) and controls (79?±?9?% and 31?±?6?% p?=?0.7 for both) explained by increased RV cross sectional area in patients. LV function is affected in patients with PH despite preserved global LV function. The decreased longitudinal contribution and increased lateral contribution to LVSV was not seen in the RV, contrary to previous findings in patients with volume loaded RVs.     

Assessment of left atrial volumes in sinus rhythm and atrial fibrillation using the biplane area-length method and cardiovascular magnetic resonance imaging with TrueFISP.

OBJECTIVES: To determine whether the biplane area-length method can be used for the evaluation of left atrial volumes and ejection fraction with cardiovascular magnetic resonance imaging (CMR) by TrueFISP in normal subjects and patients with atrial fibrillation. BACKGROUND: Atrial fibrillation is the most common arrhythmia in elderly patients. Left atrial size and volumes play an important role in predicting short and long-term success after cardioversion. METHODS: Fifteen healthy subjects (mean age 65.6+/-6.4 years) and 18 patients (mean age 67.2+/-8.8 years) with atrial fibrillation were examined by CMR (Magnetom, Siemens, Erlangen, Germany). Images were acquired by TrueFISP using the horizontal and vertical long-axis plane to measure left atrial end-diastolic and end-systolic areas and longitudinal dimensions. Volumes were determined with commercially available software. Left atrial end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were determined by the biplane area-length method and compared to findings obtained by the standard short-axis method. Images were acquired and analyzed a second time in the patients with atrial fibrillation. RESULTS: There was no difference in age between men and women (p=0.147) and healthy subjects and patients (p=0.128) included in the study. EDV and ESV were significantly higher and SV and EF significantly lower in patients with atrial fibrillation than in healthy subjects (p < or = 0.009), regardless of the method used. The values obtained for EDV and ESV by the biplane area-length method were significantly higher in both healthy subjects (p<0.001) and patients with atrial fibrillation (p<0.001) than those obtained by the standard short-axis approach, whereas SV (p> or = 0.057) and EF (p> or = 0.118) did not differ significantly. In the second investigation in patients with atrial fibrillation, ESV, SV, and EF did not differ significantly between the two methods (p> or =0.481). Assessment of interobserver variability revealed good agreement in the findings of the two observers, both in normal sinus rhythm and atrial fibrillation (overall variability 0.8+/-6.5%). CONCLUSIONS: The biplane area-length method can be used in CMR images obtained by TrueFISP to assess left atrial volumes and ejection fraction in normal subjects and patients with varying cardiac cycle length, as in atrial fibrillation.     

My paper 20 years later: Effect of positive end-expiratory pressure on right ventricular function in humans

Introduction

In 1992, we published a report on the effect of positive end-expiratory pressure (PEEP) on right ventricular (RV) function in humans.

Results

We measured RV volumes and pressures and pericardial pressure (Ppc) as PEEP was increased from zero to 15 cm H20 in 12 patients after thoracotomy, using a pulmonary arterial catheter equipped with a rapid responding thermistor that allowed measurement of RV ejection fraction (RVef), while Ppc was measured via a pericardial balloon catheter. RV end-diastolic volume (EDV) was estimated as the ratio of stroke volume (SV) to RVef, whereas RV end-systolic volume (ESV) were estimated as RV EDV-SV. PEEP increased Ppc and Pra, but RVef unaltered. There was no relation between either RV filling pressure (Pra-Ppc) and EDV or the change in RV filling pressure and EDV, although EDV varied significantly with PEEP (p < 0.05). The relations between EDV and both SV and RVef were weak (r = 0.54 and 0.55, respectively). RVef varied inversely with ESV (r = ?0.77), although it showed no relation to transmural peak pulmonary artery pressure (r = 0.28). However, both absolute and relative changes in EDV corresponded closely with respective ESV values (r = 0.94). We concluded that EDV varies independently of changes in filling pressure and that changes in ESV occur independently of changes in ejection pressure. These data can be explained by assuming that the RV shape changes can dissociate changes in RV EDV from changes in RV wall stress (preload). Thus, changes in RV EDV may or may not alter SV but should proportionately change ESV to a degree dependent on election pressure and contractility.

Conclusions

Subsequent studies confirmed our findings which can be summarized as 1) RV filling is independent of Pra; thus central venous pressure cannot be used to estimate RV preload; and 2) for cardiac output to increase by the Starling mechanism the RV must dilate increasing RV ESV. Since the pericardium limits absolute biventricular volume, there is a finite limit to which cardiac output can increase by the Starling mechanism defined not by left ventricular contractility but by RV function. And 3) if fluid loading causes Pra to increase without increasing cardiac output, then resuscitation should stop as the patient is going into acute cor pulmonale. These truths help bedside clinicians understand the echocardiographic and hemodynamic signatures of both RV failure and volume responsiveness.     

Optimizing right ventricular focused four-chamber views using three-dimensional imaging,a comparative magnetic resonance based study

Obtaining focused right ventricular (RV) apical view remains challenging using conventional two-dimensional (2D) echocardiography. This study main objective was to determine whether measurements from RV focused views derived from three-dimensional (3D) echocardiography (3D-RV-focused) are closely related to measurements from magnetic resonance (CMR). A first cohort of 47 patients underwent 3D echocardiography and CMR imaging within 2 h of each other. A second cohort of 25 patients had repeat 3D echocardiography to determine the test–retest characteristics; and evaluate the bias associated with unfocused RV views. Tomographic views were extracted from the 3D dataset: RV focused views were obtained using the maximal RV diameter in the transverse plane, and unfocused views from a smaller transverse diameter enabling visualization of the tricuspid valve opening. Measures derived using the 3D-RV-focused view were strongly associated with CMR measurements. Among functional metrics, the strongest association was between RV fractional area change (RVFAC) and ejection fraction (RVEF) (r?=?0.92) while tricuspid annular plane systolic excursion moderately correlated with RVEF (r?=?0.47), all p?<?0.001. Among RV size measures, the strongest association was found between RV end-systolic area (RVESA) and volume (r?=?0.87, p?<?0.001). RV unfocused views led on average to 10% underestimation of RVESA. The 3D-RV-focused method had acceptable test–retest characteristics with a coefficient of variation of 10% for RVESA and 11% for RVFAC. Deriving standardized RV focused views using 3D echocardiography strongly relates to CMR-derived measures and may improve reproducibility in RV 2D measurements.     

Left and right ventricular parameters corrected with threshold-based quantification method in a normal cohort analyzed by three independent observers with various training-degree

While cardiac magnetic resonance (CMR) is the reference method to evaluate left and right ventricular functions, volumes and masses, there is no widely accepted method for the quantitative analysis of trabeculae and papillary muscles (TPM). The aim of this study was to investigate the effect of TPM quantification on left and right ventricular CMR values in a normal cohort and to investigate interobserver variability of threshold-based (TB) analysis by three independent observers with variant experience in CMR. At our clinic, 60 healthy volunteers (30 males, mean age 25.6?±?4.7 years) underwent CMR scan performed on a 1.5T Philips Achieva MR machine. On short-axis cine images, endo- and epicardial contours were detected by three independent observers with variable experience in CMR (low- ca. 120, mid- >?800, high-experienced?>?5000 original CMR cases). Using Conv and TB methods (Medis 7.6 QMass software Leiden, The Netherland), we measured LV and RV ejection fractions, end-diastolic, end-systolic, stroke volumes and masses. We used TB method for quantifying TPM in ventricles using epicardial contour layers. Interobserver variability was evaluated, and the observer’s experience as an impact on variability of each investigated parameters was assessed. Comparing Conv and TB quantification methods’ significant difference were detected for all LV and RV parameters in case of all observers (H, M and L p?<?0.0001). The global intraclass correlation coefficient (G-ICC) representing interobserver agreement for all investigated parameters was lower with Conv method (G-ICC_Conv vs. G-ICC_TB 0.86 vs. 0.92 p?<?0.0001). The ICC of LV parameters was higher using TB quantification (LV-ICC_Conv vs. LV-ICC_TB 0.92 vs. 0.96 p?<?0.0001), and for the evaluation of RV values, the TB method also had significantly higher interobserver agreement (RV-ICC_Conv vs. RV-ICC_TB 0.80 vs. 0.89 p?<?0.0001). The TB algorithm could be a consistent method to assess LV and RV CMR values, and to measure trabeculae and papillary muscles quantitatively in various level of experience in CMR.