Myocardial Function in Offspring Aged 5 to 8 Years of Pregnancy Complicated by Severe Preeclampsia Measured by Two-Dimensional Speckle-Tracking Echocardiography

Objective: This study aimed to quantitatively assess myocardial strain in preterm children aged 5 to 8 years of pregnancy complicated by severe preeclampsia (PE) by two-dimensional (2D) speckle tracking echocardiography.Method: A cohort study of 23 preterm children delivered by severe PE pregnant women from 2010 to 2012 in the First Affiliated Hospital of Soochow University was carried out. 23 preterm children from uneventful pregnancies in the same period served as controls. Myocardial functions including left ventricular longitudinal strain, radial strain, circumferential strain, and right ventricular longitudinal strain were evaluated by conventional Doppler, tissue Doppler imaging, and 2D speckle-tracking echocardiography (2D STE). All examinations were performed by an experienced ultrasonographer using the VIVID E9 (GE Healthcare) machine, according to standard techniques.Results: Children aged 5–8 years delivered from severe PE presented less weight (24.41 vs. 20.89 kg, P < 0.05), shorter height (124.1 vs 115.6 cm, P < 0.05) and faster heart rates (84 vs. 93 bpm, P < 0.05) compared to offspring of normotensive women. There were no significant differences in global left ventricular longitudinal strain, radial strain, circumferential strain, and right ventricular longitudinal strain between the children in the experimental group and the control group (P > 0.05).Conclusion: Exposure to the intrauterine environment of severe PE during the fetal period did not have a significant impact on cardiac structure in premature children at 5–8 years old, but they had a higher resting heart rate which may be associated with cardiovascular disease in the long run.

415 Correlation between tissue abnormalities and myocardial deformation indices in arrhythmogenic cardiomyopathy: a pilot study

Aims To evaluate the correlation between cardiac magnetic resonance (CMR) tissue abnormalities and impairment of myocardial deformation indices in patients with definite diagnosis of arrhythmogenic cardiomyopathy (AC). Methods and results 41 AC Patients with available CMR study were enrolled. Myocardial deformation indices (i.e. global longitudinal strain -GLS-; global circumferential strain -GCS-; global radial strain -GRS-) for both ventricles were calculated using feature tracking analysis. Quantification of tissue abnormalities (i.e. late gadolinium enhancement -LGE- extension expressed as percentage of total ventricular mass) was performed. Spearman’s rho correlation was evaluated. Mean age was 44 ± 13 years and 26 (63%) patients were male. Mean left ventricular (LV) ejection fraction (EF) was 54 ± 10% and mean right ventricular (RV) EF was 49 ± 12%. Median LV LGE extension was 8.9% (1.05–21) and median RV LGE extension was 0 (0–6.92). All myocardial deformation indices were moderately associated with LGE extension (for LV 3D GLS Spearman’s Rho 0.423, P 0.016; 2D GCS Spearman’s Rho 0.388, P 0.028; 3D GCS 0.362, P 0.042; 2D GRS Spearman’s Rho −0.417, P 0.018; 3D GRS −0.396, P 0.025; for RV 2D GLS Spearman’s Rho 0.385, P 0.030; RV GCS Spearman’s Rho 0.450, P 0.010; RV GRS Spearman’s Rho −0.459, P 0.008). Conclusions All myocardial deformation indices showed a moderate association with LGE extension in a cohort of patients with definite AC. Further studies are needed to validate this observation and understand its implications.

292 Mechanical stress, myocardial deformation abnormalities, and ventricular fibrosis: a fatal cascade in arrhythmic mitral valve prolapse patients

Aims Arrhythmic mitral valve prolapse (MVP) is characterized by left ventricular (LV) fibrosis in the basal inferolateral wall and papillary muscles. We hypothesized that LV fibrosis are driven by excessive mechanical forces acting on myocardial susceptible cells, representing the last step in the MVP-induced myocardial stretch process. We evaluated the LV myocardial deformation, using strain assessed with cardiac magnetic resonance (CMR), in arrhythmic MVP patients with normal LV ejection fraction (LVEF) and absent/trivial mitral regurgitation (MR) and its correlation with the presence of LV fibrosis, detected by late gadolinium enhancement (LGE) in post-contrast CMR images. Methods and results We enrolled consecutive arrhythmic MVP patients with normal LVEF and no/trivial MR. Sixty-nine (39 female; median age: 40 years) patients without MVP, arrhythmias or cardiovascular history served as control group. All patients underwent CMR for identification of LGE and evaluation of LV myocardial deformation. A total of 66 patients were enrolled (47 female; median age: 44 years). In the overall MVP population, LGE was present in 41 patients (62.1%). MVP patients without LGE (25 patients, 37.9%) presented a higher global radial (median: 42.19 vs. 33; P <0.0001) and higher global longitudinal strain (median: −21.61 vs. −18.10; P <0.0001), compared to the control group. A reduction of regional basal posterolateral radial (BPL median: 50.60 vs. 67.30; P = 0.0015) and longitudinal strain (BPL median: −23.50 vs. −26.70; P = 0.0186) were observed in the MVP patients as compared with controls (Figures A–D). Conversely to the basal region, mid anterolateral and posterolateral region presented a higher radial (MAL median: 52.60 vs. 31.10; P < 0.0001 and MPL median: 52.80 vs. 21.50; P < 0.0001) and longitudinal strain (MAL median: −24.80 vs. −18.30; P < 0.0001 and MPL median: −25.30 vs. −14.80; P < 0.0001), when compared to control group. MVP patients with LGE had a lower global radial (median: 36.48 vs. 42.19; P <0.0047), longitudinal (median: −19.18 vs. −21.61; P = 0.0013), and circumferential strain (median: −17.80 vs. −19.28; P = 0.0134) compared with those without fibrosis. According to MVP patients without LGE, the presence of fibrosis is associated with a lower regional radial (BAL median: 64.40 vs. 82.80; P = 0.0481; MAL median: 42.60 vs. 52.60; P = 0.0287) and circumferential strain (BAL median: −21.90 vs. −24.20; P = 0.0174; BPL median: −16.80 vs. −18.80; P = 0.0411; MPL median: −15.50 vs. −19.40; P = 0.0077) in the LV basal-mid lateral walls (Figures E–H). 292 Figures A–D and E-H Conclusions Arrhythmic MVP patients with normal LV systolic function and absent/trivial MR presented an abnormal myocardial deformation pattern. The reduced strain in BPL wall of MVP patients without LGE could be considered as an early marker of MVP-induced myocardial stress, that could promote, time by time, LV fibrosis and arrhythmias in MVP patients.

Assessment of left ventricular mechanics in right ventricular overload using in silico rat models

Background To preserve cardiac function in overload conditions, the RV adapts by developing muscular hypertrophy through progressive tissue remodelling. This process may lead to a vicious cycle with detrimental effects on RV diastolic and systolic function, as seen in pulmonary arterial hypertension (PAH) patients [1]. However, how RV overload affects LV function and remodelling remains an open question [2]. Computational models of cardiac physiology offer an opportunity for investigating mechanisms difficult or impossible to analyse otherwise due to the existence of overlapping factors and technical limitations. Aim This study aims to assess the acute effects of RV overload and increased myocardial passive stiffness on the LV mechanical properties in an anatomically-based computational model of healthy rat heart. Methods A computational simulation pipeline of cardiac mechanics based on the Holzapfel-Ogden model has been implemented using MR images from a healthy rat. Whereas LV function was modelled realistically using catheter measurements conducted on the same subject than the MR imaging, RV function was based on representative literature values for healthy and PAH rats with RV overload. The following cases were defined (Fig. 1): CTRL, with normal RV function; PAH1, with 30% increase in RV ESV (end-systolic volume) and 15% increase in RV ESP (end-systolic pressure) in comparison to CTRL; and PAH2, with 60% increase in RV ESV and 30% increase in RV ESP compared to CTRL. The cardiac cycle was simulated for all cases whilst fitting the experimentally measured LV pressure and volume values from a healthy rat, which allowed quantifying the effects of RV overload on LV function. Results The increase of average circumferential strain in the LV correlated with the degree of RV overload simulated (CTRL: −8.7%, PAH1: −8.9%, PAH2: −9.2%), whilst average radial (CTRL: 35.2%, PAH1: 34.8%, PAH2: 30.3%) and longitudinal strains decreased (CTRL: −7.7%, PAH1: −7.4%, PAH2: −6.6%), as seen in Fig.2. However, regional differences in strain were significant: under RV overload conditions, circumferential strain increased in the septum (−3.5% difference in PAH2 vs. CTRL) but lower values were observed in the lateral wall (+1.7% difference in PAH2 vs. CTRL). Cardiac function of case PAH2 was simulated also with increased myocardial passive stiffness (2.67 kPa instead of 1.34 kPa) which presented a mild strain increase in the mid LV ventricle in comparison to PAH2 with normal stiffness (circumferential strain: −0.8%, radial strain: +0.5%, longitudinal strain: −0.2%). Conclusion Our study provides mechanistic evidence on how RV overload and increased passive myocardial stiffness causes a redistribution of strain and fibre stress in the LV, which may play a significant role in LV remodelling and function. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): K.G. Jebsen Center for Cardiac Research Figure 1. Pressure – volume loops Figure 2. Mean mid-LV strains

A method based on circumferential strain distribution for roller path design in conventional spinning of thin-walled conical part with curved surface

Multi-pass conventional spinning is the preferable forming technology for the forming of thin-walled conical part with curved surface (TCPCS) in aerospace field. In multi-pass conventional spinning, the design of roller path is a critical problem due to its sensitive effect on the deformation mode and forming defect during spinning process. However, at present, the roller path is still mainly designed based on experience and trial-and-error, which seriously restricts the high-performance spinning of TCPCS. In this work, a new quantitative method based on circumferential strain distribution was developed for the roller path design in multi-pass conventional spinning of TCPCS. In this method, the total required circumferential strain for the forming of final TCPCS by conventional spinning was firstly determined. Then, the spinning passes number were obtained through dividing the total required circumferential strain by the ultimate circumferential strain producing the spinning instability ( ε θult ). As for the roller path profile in each pass, it is divided into two sections and determined respectively, i.e. the attaching mandrel section and the performing section. The attaching mandrel section presents the same profile of mandrel. The profile of preforming section is determined point-by-point by distributing the rest of circumferential strain { ε θni } to produce the final TCPCS. The point-by-point distributed circumferential strain is half of the { ε θni } at the initial stage until reaches the half of ε θult , then it will keep the half of ε θult to the end. The proposed new method of roller path design was validated by finite element simulation, where well spinning stability, wall thickness distribution and roundness were obtained. This method provides a quantitative, high-efficient and universal way for the roller path design in conventional spinning of TCPCS.

Morphological and functional cardiac consequences of rapid hypertension treatment: a cohort study

Background Left ventricular (LV) hypertrophy (LVH) in uncontrolled hypertension is an independent predictor of mortality, though its regression with treatment improves outcomes. Retrospective data suggest that early control of hypertension provides a prognostic advantage and this strategy is included in the 2018 European guidelines, which recommend treating grade II/III hypertension to target blood pressure (BP) within 3 months. The earliest LVH regression to date was demonstrated by echocardiography at 24 weeks. The effect of a rapid guideline-based treatment protocol on LV remodelling, with very early BP control by 18 weeks remains controversial and previously unreported. We aimed to determine whether such rapid hypertension treatment is associated with improvements in LV structure and function through paired cardiovascular magnetic resonance (CMR) scanning at baseline and 18 weeks, utilising CMR mass and feature tracking analysis. Methods We recruited participants with never-treated grade II/III hypertension, initiating a guideline-based treatment protocol which aimed to achieve BP control within 18 weeks. CMR and feature tracking were used to assess myocardial morphology and function immediately before and after treatment. Results We acquired complete pre- and 18-week post-treatment data for 41 participants. During the interval, LV mass index reduced significantly (43.5 ± 9.8 to 37.6 ± 8.3 g/m2, p < 0.001) following treatment, accompanied by reductions in LV ejection fraction (65.6 ± 6.8 to 63.4 ± 7.1%, p = 0.03), global radial strain (46.1 ± 9.7 to 39.1 ± 10.9, p < 0.001), mid-circumferential strain (− 20.8 ± 4.9 to − 19.1 ± 3.7, p = 0.02), apical circumferential strain (− 26.0 ± 5.3 to − 23.4 ± 4.2, p = 0.003) and apical rotation (9.8 ± 5.0 to 7.5 ± 4.5, p = 0.003). Conclusions LVH regresses following just 18 weeks of intensive antihypertensive treatment in subjects with newly-diagnosed grade II/III hypertension. This is accompanied by potentially advantageous functional changes within the myocardium and supports the hypothesis that rapid treatment of hypertension could improve clinical outcomes. Trial registration: ISRCTN registry number: 57475376 (assigned 25/06/2015).