Global Left Ventricle Function Research Articles

Assessment of global and segmental strain in heterozygous APE1/Ref-1 transgenic mice using cardiac magnetic resonance imaging

Abstract Background Apurinic/apyrimidinic-endonuclease1(APE1/Ref-1) is a redox factor necessary for DNA binding and transcription regulator in ROS generation. The association between APE1/Ref-1 and heart failure(HF) has been observed in previous studies. Heterozygous APE1/Ref-1 transgenic mice displayed endothelial cell dysfunction with systemic hypertension. Global strain(GS) measures the myocardium's deformation along its axis and is known to be a sensitive marker of subclinical HF in hypertensive patients with preserved ejection fraction. Purpose This study aims to investigate the functional dynamics and GS of the heart in heterozygous APE1/Ref-1 mice to help identify the association between APE1/Ref-1 and early signs of HF and translate to clinical applications. Methods A study was conducted to assess the functional parameters of both the left ventricle(LV) and right ventricle (RV) and perform LV global and segmental strain analysis using cardiac magnetic resonance imaging(CMR) in heterozygous APE1/Ref-1 transgenic mice(n=4) and wild type mice (n=4) of age 10-12 weeks. A 7T CMR scanner and FSE T1 sequence were used to acquire short-axis views of mouse cardiac images. LV and RV functional parameters including ejection fraction(EF), stroke volume(SV), cardiac output, peak filling rate, peak emptying rate and strain indices including global circumferential strain, global radial strain, segmental circumferential strain, and segmental radial strain were calculated with a software dedicated to analyzing CMR images. Global LV and RV function was quantified both manually and using an AI-based algorithm of LV and RV segmentation. The strain analysis was performed using the strain medical image tracking toolbox module. Additionally, reproducibility testing was done to validate the accuracy of AI-driven calculations. Results We found that heterozygous APE1/Ref-1 mice displayed a decrease in SV(8.00±0.01ul vs 9.75±0.96ul, p=0.01) and LVEF(58.75±2.63% vs 66.50±2.89%, p=0.007) compared to controls while the functional parameters of RV were similar. Interestingly, the circumferential strain rate of LV was significantly reduced in APE1/Ref-1 mice compared to controls(p<0.001), particularly in the systolic phase. In addition, the study showed that manually-calculated and AI-derived indices were within an acceptable margin of error, rendering the AI system reproducible and reliable in calculating volumetric parameters and strain of the mice's hearts. Conclusions This study demonstrated that LV global circumferential strain rate, along with SV and LVEF decreased in heterozygous APE1/Ref-1 transgenic mice. These parameters could serve as markers for assessing early functional changes of mice hearts in a non-invasive manner. Volumetric and strain indices measured by AI-based analysis of mouse CMR images are reproducible parameters for cardiovascular research in small animals.LV strain analysis of mice CMRTable of volumetric parameters

Automated estimation of mitral annular plane systolic excursion by artificial intelligence from 3D ultrasound recordings

Perioperative monitoring of cardiac function is beneficial for early detection of cardiovascular complications. The standard of care for cardiac monitoring performed by trained cardiologists and anesthesiologists involves a manual and qualitative evaluation of ultrasound imaging, which is a time-demanding and resource-intensive process with intraobserver- and interobserver variability. In practice, such measures can only be performed a limited number of times during the intervention. To overcome these difficulties, this study presents a robust method for automatic and quantitative monitoring of cardiac function based on 3D transesophageal echocardiography (TEE) B-mode ultrasound recordings of the left ventricle (LV). Such an assessment obtains consistent measurements and can produce a near real-time evaluation of ultrasound imagery. Hence, the presented method is time-saving and results in increased accessibility. The mitral annular plane systolic excursion (MAPSE), characterizing global LV function, is estimated by landmark detection and cardiac view classification of two-dimensional images extracted along the long-axis of the ultrasound volume. MAPSE estimation directly from 3D TEE recordings is beneficial since it removes the need for manual acquisition of cardiac views, hence decreasing the need for interference by physicians. Two convolutional neural networks (CNNs) were trained and tested on acquired ultrasound data of 107 patients, and MAPSE estimates were compared to clinically obtained references in a blinded study including 31 patients. The proposed method for automatic MAPSE estimation had low bias and low variability in comparison to clinical reference measures. The method accomplished a mean difference for MAPSE estimates of (−0.16±1.06) mm. Thus, the results did not show significant systematic errors. The obtained bias and variance of the method were comparable to inter-observer variability of clinically obtained MAPSE measures on 2D TTE echocardiography. The novel pipeline proposed in this study has the potential to enhance cardiac monitoring in perioperative- and intensive care settings.

Changes in Left Heart Geometry, Function, and Blood Serum Biomarkers in Patients with Obstructive Sleep Apnea after Treatment with Continuous Positive Airway Pressure.

Background: Cardiovascular remodeling is essential in patients with obstructive sleep apnea (OSA), and continuous positive airway pressure (CPAP) therapy could improve these processes. Two-dimensional (2D) speckle-tracking (ST) echocardiography is a useful method for subclinical biventricular dysfunction diagnosis and thus might help as an earlier treatment for OSA patients. It is still not clear which blood serum biomarkers could be used to assess CPAP treatment efficacy. Objectives: To evaluate left heart geometry, function, deformation parameters, and blood serum biomarker (galectin-3, sST2, endothelin-1) levels in patients with OSA, as well as to assess changes after short-term CPAP treatment. Materials and Methods: Thirty-four patients diagnosed with moderate or severe OSA, as well as thirteen patients as a control group, were included in the study. All the subjects were obese (body mass index (BMI) > 30 kg/m2). Transthoracic 2D ST echocardiography was performed before and after 3 months of treatment with CPAP; for the control group, at baseline only. Peripheral blood samples for the testing of biomarkers were collected at the time of study enrolment before the initiation of CPAP therapy and after 3 months of CPAP treatment (blood samples were taken just for OSA group patients). Results: The left ventricle (LV) end-diastolic diameter and volume, as well as LV ejection fraction (EF), did not differ between groups, but an increased LV end-systolic volume and a reduced LV global longitudinal strain (GLS) were found in the OSA group patients (p = 0.015 and p = 0.035, respectively). Indexed by height, higher LV MMi in OSA patients (p = 0.007) and a higher prevalence of LV diastolic dysfunction (p = 0.023) were found in this group of patients. Although left atrium (LA) volume did not differ between groups, OSA group patients had significantly lower LA reservoir strain (p < 0.001). Conventional RV longitudinal and global function parameters (S′, fractional area change (FAC)) did not differ between groups; however, RV GLS was reduced in OSA patients (p = 0.026). OSA patients had a significantly higher right atrium (RA) diameter and mean pulmonary artery pressure (PAP) (p < 0.05). Galectin-3 and sST2 concentrations significantly decreased after 3 months of CPAP treatment. Conclusions: OSA is associated with the left heart remodeling process—increased LV myocardial mass index, LV diastolic dysfunction, reduced LV and RV longitudinal strain, and reduced LA reservoir function. A short-term, 3-months CPAP treatment improves LV global longitudinal strain and LA reservoir function and positively affects blood serum biomarkers. This new indexing system for LV myocardial mass by height helps to identify myocardial structural changes in obese patients with OSA.

Multiparametric MRI identifies subtle adaptations for demarcation of disease transition in murine aortic valve stenosis

Aortic valve stenosis (AS) is the most frequent valve disease with relevant prognostic impact. Experimental model systems for AS are scarce and comprehensive imaging techniques to simultaneously quantify function and morphology in disease progression are lacking. Therefore, we refined an acute murine AS model to closely mimic human disease characteristics and developed a high-resolution magnetic resonance imaging (MRI) approach for simultaneous in-depth analysis of valvular, myocardial as well as aortic morphology/pathophysiology to identify early changes in tissue texture and critical transition points in the adaptive process to AS. AS was induced by wire injury of the aortic valve. Four weeks after surgery, cine loops, velocity, and relaxometry maps were acquired at 9.4 T to monitor structural/functional alterations in valve, aorta, and left ventricle (LV). In vivo MRI data were subsequently validated by histology and compared to echocardiography. AS mice exhibited impaired valve opening accompanied by significant valve thickening due to fibrotic remodelling. While control mice showed bell-shaped flow profiles, AS resulted not only in higher peak flow velocities, but also in fragmented turbulent flow patterns associated with enhanced circumferential strain and an increase in wall thickness of the aortic root. AS mice presented with a mild hypertrophy but unaffected global LV function. Cardiac MR relaxometry revealed reduced values for both T1 and T2 in AS reflecting subtle myocardial tissue remodelling with early alterations in mitochondrial function in response to the enhanced afterload. Concomitantly, incipient impairments of coronary flow reserve and myocardial tissue integrity get apparent accompanied by early troponin release. With this, we identified a premature transition point with still compensated cardiac function but beginning textural changes. This will allow interventional studies to explore early disease pathophysiology and novel therapeutic targets.

Left ventricular myocardial deformation assessment in asymptomatic patients with recently diagnosed sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis

BackgroundSarcoidosis is a systemic granulomatous disease affecting different organs including the heart. Myocardial strain analysis could potentially detect the early stages of cardiac dysfunction in sarcoidosis patients. The present study aims to assess the use of cardiac magnetic resonance (CMR) strain analysis using feature tracking (FT) in the detection of early cardiac involvement in asymptomatic patients with sarcoidosis.MethodsOne hundred and thirteen CMR studies of patients with sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis without pre-existing known cardiovascular disease were included in the study and analysed using FT and compared to 22 age and gender-matched controls. Global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) of the left ventricle (LV) were measured.ResultsThe sarcoidosis patients did not significantly differ from the controls in basic demographic data and had normal global and regional systolic LV function—LV ejection fraction (EF) 66 ± 7% vs 65 ± 5% in the controls (p = NS). No statistically significant differences were found in all strain parameters between patients and controls: GLS (− 13.9 ± 3.1 vs. − 14.2 ± 2.5), GCS (− 23.4 ± 4.0 vs. − 22.2 ± 2.9) and GRS (53.4 ± 13.5 vs. 51.2 ± 13.6%) (p = NS).ConclusionPatients with sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis had normal myocardial deformation measured by CMR-FT derived global strain

Feature tracking cardiovascular magnetic resonance in asymptomatic patients with extracardiac sarcoidosis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Regional Development Fund - Project ENOCH (No. CZ.02.1.01/0.0/0.0/16_019/0000868) and the Specific University Research (MUNI/A/1685/2020) provided by the Ministry of Education, Youth and Sports of the Czech Republic (MEYS CR) in the year 2020. Introduction Sarcoidosis is a systemic granulomatous disease affecting many organs including heart. Myocardial strain analysis could potentially detect early stadia of cardiac dysfunction in sarcoidosis patients. Purpose The study aims to assess use cardiac magnetic resonance (CMR) strain analysis using feature tracking (FT) in the detection of early cardiac involvement in asymptomatic patients with sarcoidosis. Methods One hundred thirteen CMR studies of patients with extracardiac sarcoidosis without pre-existing known cardiovascular disease were included into the study and analysed using FT and compared to 22 age and gender matched controls. Global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) of left ventricle (LV) were measured. Results The sarcoidosis patients did not significantly differ from controls in basic demographic data and had normal global and regional systolic LV function – LV ejection fraction (EF) 66 ± 7% vs 65 ± 5% in controls (p = NS). No statistically significant differences were found in all strain parameters between patients and controls: GLS (-13.9 ± 3.1 vs. -14.2 ± 2.5), GCS (-23.4 ± 4.0 vs. -22.2 ± 2.9) and GRS (53.4 ± 13.5 vs. 51.2 ± 13.6%) (p = NS). Conclusion Asymptomatic patients with extracardiac sarcoidosis had normal myocardial deformation measured by CMR-FT derived global strain.

Elucidating the mechanisms underlying left ventricular function recovery in patients with ischemic heart failure undergoing surgical remodeling: A 3-dimensional ultrasound analysis

ObjectiveThe study objective was to elucidate the mechanisms of left ventricle functional recovery in terms of endocardial contractility and synchronicity after surgical ventricular reconstruction. MethodsReal-time 3-dimensional transthoracic echocardiography was performed on 20 patients with anterior left ventricle remodeling and ischemic heart failure before surgical ventricular reconstruction and at 6-month follow-up, and on 15 healthy controls matched by age and body surface area. Real-time 3-dimensional transthoracic echocardiography datasets were analyzed through TomTec software (4D LV-Analysis; TomTec Imaging Systems GmbH, Unterschleissheim, Germany): Left ventricle volumes, ejection fraction, and global longitudinal strain were computed; the time-dependent endocardial surface yielded by 3-dimensional speckle-tracking echocardiography was postprocessed through in-house software to quantify local systolic minimum principal strain as a measure of fiber shortening and mechanical dispersion as a measure of fiber synchronicity. ResultsCompared with controls, patients with heart failure before surgical ventricular reconstruction showed lower ejection fraction (P < .0001) and significantly impaired mechanical dispersion (P < .0001) and minimum principal strain (P < .0001); the latter worsened progressively from left ventricle base to apex. After surgical ventricular reconstruction, global longitudinal strain improved from −6.7% to −11.3% (P < .0001); mechanical dispersion decreased in every left ventricle region (P ≤ .017) and mostly in the basal region, where computed mechanical dispersion values were comparable to physiologic values (P ≥ .046); minimum principal strain improved mostly in the basal region, changing from −16.6% to −22.3% (P = .0027). ConclusionsAt 6-month follow-up, surgical ventricular reconstruction was associated with significant recovery in global left ventricle function, improved mechanical dispersion indicating a more synchronous left ventricle contraction, and improved left ventricle fiber shortening mostly in the basal region, suggesting the major role of the remote myocardium in enhancing left ventricle functional recovery.

Application Of Cine CT Imaging For Evaluation Of Biomechanics Of The Left Ventricle Post Myocardial Infarction And Following Intramyocardial Delivery Of Imageable Hydrogel

Introduction: Early post myocardial infarction (MI) there are regional changes in myocardial strain and stiffness in the infarct and remote areas of the left ventricle (LV) associated with changes LV geometry and global LV function that result in remodeling. In this study, we present an experimental platform to assess changes in passive biomechanics of the myocardium post MI before and after intramyocardial delivery of a imageable theranostic hydrogel, applying contrast cineCT (CCT) imaging and 3D echocardiography (ECHO).

P1336 Sometimes the heart could appear different if seen under a magnetic resonance scanner: misdiagnosed cases of isolated left ventricle apical hypoplasia and double chambered left ventricle

Abstract Introduction Congenital heart diseases (CHD) are detected in 1% of children, often usually the first year of life; however, many defects are diagnosed later or remain undiagnosed. Both congenital and acquired disorders could affect the left ventricle (LV). First-line assessment includes echocardiography; nonetheless, because of intrinsic or technical limitations and artefacts, further investigation may be required. Cardiac Magnetic Resonance (CMR) is capable of providing anatomical and functional information without many of limitations and drawbacks of echocardiography. We describe CMR findings of misdiagnosed cases of two rare congenital LV abnormalities: isolated LV apical hypoplasia (ILVAH) and double-chambered LV (DCLV). Case report 1 (image A,B,D) An 18 yrs girl diagnosed with dilated cardiomyopathy (DCM) was submitted to our CMR Lab for a functional assessment. After birth, deep Q waves in the inferior leads were noted on the ecg, and an echocardiographic examination showed a dilated and hypokinetic LV. At 1 year of age, she underwent cardiac catheterization that excluded coronary arteries anomalies and confirmed a reduced LV systolic function. A diagnosis of idiopathic DCM was formulated and she was initiated with anticongestive therapy. During the follow-up she felt well with normal exercise tolerance, longitudinal echocardiography did not show any substantial modification over the years. In 2018, a CMR study was performed. Surprisingly, the cardiac apex was formed exclusively by the right ventricle, wrapped around the LV. The LV appeared spherical and truncated inferiorly, and the apical portion was missing; LV volumes and ejection fraction were normal; regional akinesia and subendocardial late gadolinium enhancement (LGE) were evident at the inferior wall. These findings were consistent of ILVAH. Case Report 2 (image C,E,F) A 24 yrs old boy with prenatal diagnosis of LV diverticulum came to our observation for a CMR study. He was asymptomatic, particularly, no palpitations or syncope were referred, nor arrhythmias were detected during the follow-up; exercise tolerance was normal. CMR showed a coarse muscle band in the LV cavity, extending from the apex to the posterior papillary muscle, thus delimiting a contractile accessory chamber. LV volumes and global systolic function were normal. The LV accessory chamber presented a normal structured free lateral wall with a normal systolic thikening, except at the apical infero-lateral segment where it appeared thinned and akinetic and showed LGE with a subendocardial pattern. These findings were consistent of DCLV. Conclusions the LV could be affected by many diseases with different etiological, clinical and morphological features. Compared to other imaging diagnostic modalities, CMR allows better definition of LV morphology, function and tissue characterization, becoming essential for LV abnormalities diagnosis and follow-up. Abstract P1336 Figure.

The evaluation of diastolic function and myocardial performance index during pregnancy: A tissue Doppler echocardiography study

The pregnancy process is characterized by several changes in the cardiovascular system, especially in left ventricle (LV) systolic and diastolic function. Tissue Doppler imaging (TDI) is a useful tool to evaluate global LV function. This study investigated changes in LV functions using TDI in third-trimester pregnant women. A total of 86 consecutive third-trimester healthy pregnant women and 40 age-matched nonpregnant healthy women (control group) were enrolled in this cross-sectional study. LV diameter, standard Doppler and tissue Doppler parameters, and myocardial performance index (MPI) were measured for all patients. There was no significant difference in baseline characteristics between the pregnant and control groups. However, the cardiac chamber diameter was larger, the Am velocity was higher, and the E velocity, Em velocity, and E/A ratio were lower in the pregnant group. In addition, the MPI was significantly higher in the pregnant group compared to the control group (0.57±0.11 vs 0.42±0.02, P<.001). Correlation analysis showed that gestational week was positively correlated with the MPI (r=.407, P=.003). Detailed assessment of cardiac function is important during pregnancy. We demonstrated that pregnancy was associated with a significantly increased MPI, as well as structural and functional changes.

A Pilot Study of Third-Generation Dual-Source Computed Tomography for the Assessment of Global Dynamic Changes in Left Ventricular Structure and Function in a Porcine Model of Acute Myocardial Infarction.

BackgroundFirst-generation and second-generation dual-source computed tomography (DSCT) are useful for analyzing left ventricle (LV) structure and function. This pilot study aimed to investigate the feasibility and role of third-generation DSCT for the evaluation of dynamic changes in LV structural and functional characteristics in a Diannan small-ear pig model of acute myocardial infarction (AMI).Material/MethodsThe model of AMI was established by balloon occlusion of the distal third of the left anterior descending (LAD) coronary artery in 14 Diannan small-eared pigs. Third-generation DSCT was performed to observe dynamic changes in LV structure and function before and after AMI was induced, with a follow-up period of 30 days.ResultsThe mean structural measurements at baseline included interventricular septum thickness (8.50±0.90 mm), LV anterior wall thickness (8.40±1.30 mm), LV posterior wall thickness (7.80±1.20 mm), LV end-diastolic dimension (LVEDD) (45.00±4.90 mm), and LV end-systolic dimension (LVESD) (25.90±4.10 mm). The mean functional measurements at baseline included the LV end-diastolic volume (LVEDV) (74.62±13.54 ml), LV end-systolic volume (LVESV) (23.06±7.46 ml), LV ejection fraction (LVEF) (69.29±6.83%), LV mass (86.35±14.02 g), stroke volume (SV) (51.56±9.77 ml), and cardiac output (CO) (4.22±2.14 l/min). Trends of time-dependent changes were observed for LVESV, LVEF, SV, and CO, but not for LVEDV or LV mass.ConclusionsThird-generation DSCT was validated as a tool for assessing dynamic changes in LV global function in a porcine model of AMI.

P1508The Coronary Arteriogenesis with combined Heparin and Exercise therapy in chronic refractory Angina (CARHEXA) trial: a double-blind randomized placebo-controlled stress echocardiographic study

Abstract Background Coronary collateral circulation exerts protective effects on myocardial ischemia due to coronary artery disease (CAD) and can be promoted by exercise (E) with heparin (H) co-administration. Whether this arteriogenetic effects is accompanied by functional improvement of left ventricle (LV) during stress remains unknown. Purpose To establish the stress-induced functional effects on LV regional and global function of 2-week cycle of H+E in patients with “no-option” CAD. Methods In a prospective, single-center, double-blind, randomized, parallel-group study we recruited 32 “no-option” patients (27 males; mean age of 61±8 years), with stable angina and CTO, refractory to OMT, not suitable for revascularization and with E-induced ischemia. All underwent 2-week cycle of E (2 E test per day, 5 days a week) and were pre-treated with i.v. 0.9% saline or unfractionated H (100 IU/kg up to maximum of 5.000IU, 10 min prior to E). Canadian Class Score (CCS) and 12-lead E-ECG for time-to-1 mm ST-segment depression were assessed at entry and after treatment. LV function was evaluated during treadmill exercise with conventional and advanced imaging indices: Wall Motion Score Index (WMSI); Ejection Fraction (EF); Force (systolic blood pressure/end-systolic volume); Global Longitudinal Strain (GLS). Results Post-treatment exercise-time and CCS improved in both groups. In H+E patients exercise-time improved from 369.8±107.8 sec to 475.3±114.6 sec (p=0.001) while in E patients improved from 384±152.7 sec to 464.8±134.1 sec (p=0.019). CCS score changed in H+E from 2.6±0.7 to 1.9±0.7 (p=0.000), and in E group from 2.4±0.7 to 2.1±0.9 (p=0.046). At peak exercise, H+E was different from E group for EF and GLS (see Table). Effects of H+E on SE parameters H+E p P+E p *H+E vs P+E STRESS Time 0 vs Time 1 Time 0 vs Time 1 Time 0 Time 1 WMSI 1.377 vs 1.279 0.005 1.404 vs 1.376 0.290 0.626 0.255 EF (%) 60.9 vs 64.8 0.016 61.2 vs 57.8 0.284 0.943 0.016 Force (mmHg/mL) 6.36 vs 6.5 0.158 5.82 vs 4.68 0.209 0.760 0.098 GLS (%) −16.96 vs −18.50 0.001 −15.79 vs −15.60 0.380 0.325 0.027 SE = stress echocardiography; H+E = heparin+exercise; P+E = placebo+exercise; Time 0 = before randomization; Time 1 = after 2-week therapy cycle. *p values. Conclusion A 2-week, H+E cycle is associated with improvement in regional and global LV function during exercise, concordantly shown by conventional (WMSI, EF) and advanced (GLS) echocardiographic indices of LV function. This integrates and supplements the classical objective index based on ST-segment depression, unable to localize and quantify the functional consequences of therapy on myocardial ischemia.

Quantitative Assessment of Left Ventricular Dysfunction in Fetal Ebstein's Anomaly and Tricuspid Valve Dysplasia

Fetal Ebstein's anomaly and tricuspid valve dysplasia (EA/TVD) are associated with high perinatal mortality relative to pulmonary atresia with intact ventricular septum (PAIVS), despite both requiring redistribution of the cardiac output (CO) to the left ventricle (LV). LV dysfunction is suspected to contribute to adverse outcomes in EA/TVD. We sought to examine global and segmental LV function in fetal EA/TVD with comparison to normal controls and PAIVS. We hypothesized that LV dysfunction in EA/TVD is associated with abnormal LV remodeling and interventricular mechanics. We retrospectively identified 63 cases of fetal EA/TVD (40 with retrograde ductal flow) and 22 cases of PAIVS encountered from 2004 to 2015 and compared findings to 77 controls of comparable gestational age. We measured the combined CO and global LV function using two-dimensional, Doppler-derived, deformational (six-segmental vector velocity imaging) and dyssynchrony indices (DIs; SD of time to peak), and a novel global DI. EA/TVD fetuses demonstrated abnormal LV global systolic function with reduced ejection fraction, fractional area change, and CO, while in PAIVS we observed a normal ejection fraction, fractional area change, and CO. PAIVS, but not EA/TVD, demonstrated increased LV sphericity, suggestive of remodeling, and associated enhanced radial function in the third trimester. In contrast, while EA/TVD fetuses had normal LV segmental longitudinal strain, there was abnormal radial segmental deformation and LV dyssynchrony with increased SD of time to peak and DI. Fetal EA/TVD is associated with a lack of spherical remodeling and presence of mechanical dyssynchrony, which likely contribute to reduced CO and ejection fraction. Clinical monitoring of LV function is warranted in fetal EA/TVD. Further studies incorporating quantification of LV function into prediction models for adverse outcomes are required.

Evaluation of left ventricular strain in patients with dilated cardiomyopathy.

ObjectiveDilated cardiomyopathy (DCM) can cause structural and functional changes in the left ventricle (LV). In this study, we evaluated whether cardiac magnetic resonance tissue-tracking (MR-TT) can be applied to the detection of LV abnormalities in patients with DCM.MethodsWe used MR-TT to analyze the global peak radial strain (GPRS), global peak circumferential strain (GPCS), and global peak longitudinal strain (GPLS) in every segment of the LV in 23 patients with DCM and 25 controls. The LV ejection fraction was also measured as a function indicator.ResultsCompared with the controls, the GPRS, GPCS, and GPLS were significantly reduced in patients with DCM, indicating global LV function impairment in all directions. We also identified a significant linear correlation between the GPRS, GPCS, and GPLS and the LV ejection fraction, indicating that LV function relies on coordinated wall motion from all directions. Moreover, we found that patients with DCM had a significantly reduced magnitude of the PRS, PCS, and PLS in most segments at different levels, indicating impaired myocardial function in most LV regions.ConclusionsOur results demonstrate that LV myocardial strain in patients with DCM can be sensitively detected by MR-TT (not only the global LV function changes but also the segmental strain), which can help to identify the injured segment at an early stage and guide clinical treatment.

Myocardial extracellular volume fraction quantified by cardiovascular magnetic resonance is increased in hypertension and associated with left ventricular remodeling.

To determine whether extracellular volume fraction (ECV) quantification by cardiac magnetic resonance (CMR) can demonstrate left ventricle (LV) abnormalities and relationship between ECV and LV remodeling in hypertension (HTN) patients METHODS: ECV quantification was prospectively performed in 134 consecutive HTN patients and 97 healthy subjects. Individual and regional ECV were compared to the regions on late gadolinium enhancement (LGE) images. Statistical analysis of the relationship between LV global functional parameters and ECV was carried out using Pearson's correlation, Student's t test and multiple regressions. In the HTN group, 70.1% (94/134) were LGE negative and 29.9% (40/134) LGE positive. The mean ECV after adjusting for age, sex, BMI, diabetes, smoking and dyslipidaemia in healthy controls and LGE-negative patients were 26.9 ± 2.67% and 28.5 ± 2.9% (p < 0.001), respectively. The differences in ECV reached statistical significance among the regions of LGE, LGE-Peri, LGE remote and the normal area between the control and LGE-positive subgroup (all p < 0.05). Global ECV significantly correlated with LVEF (r = -0.466, p < 0 .001) and LV hypertrophy (r = 0.667, p < 0.001). ECV can identify LV abnormalities at an early stage in HTN patients without LGE. These abnormalities may reflect an increase in diffuse myocardial fibrosis and are associated with LV remodeling. • Diffuse myocardial fibrosis may develop in hypertensive cardiomyopathy before conventional MRI detectable LGE. • ECV can identify myocardial fibrosis at an early stage in hypertensive patients. • Elevated ECV is associated with decreased LV global function and LV remodeling in hypertension.

Intermittent pacing therapy favorably modulates infarct remodeling

Despite early revascularization, remodeling and dysfunction of the left ventricle (LV) after acute myocardial infarction (AMI) remain important therapeutic targets. Intermittent pacing therapy (IPT) of the LV can limit infarct size, when applied during early reperfusion. However, the effects of IPT on post-AMI LV remodeling and infarct healing are unknown. We therefore investigated the effects of IPT on global LV remodeling and infarct geometry in swine with a 3-day old AMI. For this purpose, fifteen pigs underwent 2 h ligation of the left circumflex coronary artery followed by reperfusion. An epicardial pacing lead was implanted in the peri-infarct zone. After three days, global LV remodeling and infarct geometry were assessed using magnetic resonance imaging (MRI). Animals were stratified into MI control and IPT groups. Thirty-five days post-AMI, follow-up MRI was obtained and myofibroblast content, markers of extracellular matrix (ECM) turnover and Wnt/frizzled signaling in infarct and non-infarct control tissue were studied. Results showed that IPT had no significant effect on global LV remodeling, function or infarct mass, but modulated infarct healing. In MI control pigs, infarct mass reduction was principally due to a 26.2 ± 4.4% reduction in infarct thickness (P ≤ 0.05), whereas in IPT pigs it was mainly due to a 35.7 ± 4.5% decrease in the number of infarct segments (P ≤ 0.05), with no significant change in infarct thickness. Myofibroblast content of the infarct zone was higher in IPT (10.9 ± 2.1%) compared to MI control (5.4 ± 1.6%; P ≤ 0.05). Higher myofibroblast presence did not coincide with alterations in expression of genes involved in ECM turnover or Wnt/frizzled signaling at 5 weeks follow-up. Taken together, IPT limited infarct expansion and altered infarct composition, showing that IPT influences remodeling of the infarct zone, likely by increasing regional myofibroblast content.

33 Association between maternal cardiac function in gestational hypertension and pregnancy outcome

Introduction It was well known that maternal cardiac function changed during pregnancy and that these changes were more pronounced in pregnancy complicated by hypertension. We were interested whether pregnancy outcome was more affected by changes in systolic or diastolic maternal function. Objective The purpose of this study was to determine the relationship of changes in function of the left ventricle (LV) with the intrauterine growth restriction (IUGR) and preterm delivery in pregnant women with gestational hypertension (GH), and reversibility of these changes after delivery. Material and Methods This study included 60 pregnant women with GH (defined as blood pressure ⩾ 140/90 mmHg that was appeared after 20th week of gestation (GW) and disappeared within six weeks postpartum). All participants underwent a complete two-dimensional, pulsed and tissue Doppler echocardiography that was used to assess parameters of diastolic function: IVRT , transmitral inflow velocities during diastole – E, A, E/A, DTE, the left ventricular filling index E/e’; parameters of systolic function: EF, cardiac output (CO), CO index (COi), IVCT, ET, stroke volume (SV), SVi, Ees, Vcf and transmitral inflow velocities during systole – velocity of septal and lateral mitral annulus: s’s and s’l; and global cardiac function: Tei index. The echo was performed in the third trimester and 6 weeks after delivery, also as 24-h ambulatory blood pressure monitoring (ABPM). Results There weren’t statistically significant differences between groups in the following parameters: age, heart rate, height, weight. Participants with IUGR had significant higher blood pressure. They also had more impaired parameters of the LV systolic and global function. Tei index was statistically significant higher in women whose children were IUGR (0,50 ± 0,05 vs 0,47 ± 0,05; p = 0,033), also IVCT was statistically significant longer (64,73 ± 11,29 vs 59,05 ± 8,42; p = 0,031). Univariate regression analysis revealed that CO had significant influence on IUGR (p = 0,001; OR 0,309; 95% CI 0,156 – 0,613), also as COi (p = 0,011; OR 0,255; 95% CI 0,089 – 0,733). Increasing CO for 1 l desceases risk of IUGR for 70%, while increasing COi for 1 l/m2 desceases risk of IUGR for 75%. Participants with preterm delivery also had significant higher blood pressure and significant more impaired parameters of the LV systolic function. SV was statistically significant lower in women with preterm delivery (55,82 ± 12,1 vs 65,69 ± 14,8; p = 0,018), also as SVi (28,61 ± 5,8 vs32,64 ± 7,3; p = 0,048) and Vcf (1,32 ± 0,2 vs 1,44 ± 0,3; p = 0,042). Univariate regression analysis revealed that EF had significant influence on preterm delivery (p = 0,012; OR 0,740; 95% CI 0,585 – 0,937). All changed echocardiographic parameters became improved six weeks after delivery. Conclusion Changes in left ventricle function in gestational hypertension predicts IUGR and preterm delivery. There was statistically significant relationship between impaired systolic and global cardiac function in gestational hypertension with IUGR, also as there was statistically significant association between impaired systolic function with preterm delivery, while there was no association between impaired diastolic function in gestational hypertension with IUGR and preterm delivery.

Abstract 16614: Left Ventricular Global Function Index (A Novel Marker of Cardiac Performance) Predicts Incident Cardiovascular Events: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

Introduction: Left ventricle (LV) function is typically evaluated independent of LV structure and vice versa. LV global function index (LVGFI) is a novel marker of cardiac performance that accounts for LV structural alterations and has been previously validated using magnetic resonance imaging. Hypothesis: We evaluated the prognostic utility of LVGFI assessed by echocardiography for incident cardiovascular disease (CVD) and heart failure (HF) events in comparison to LV ejection fraction (LVEF) and LV mass Methods: Included were 4107 Coronary Artery Risk Development in Young Adults (CARDIA) study participants with available m-mode echocardiographic parameters in 1990-1991 (Year-5). LV volumes were obtained using the Teichholz formula. LVGFI defined as LV stroke volume/LV global volume* 100, where LV global volume was calculated as the sum of the LV mean cavity volume (LVEDV + LVESV)/2) and myocardium volume (LV mass/density). Median follow-up time was 21.9 years. Cox regression models, adjusted for risk factors, were utilized to predict the endpoints of HF, hard CVD and all CVD events. Results: Mean age of participants at Year-5 was 29.8 ± 3.7 years, 55% were female, 51.3% white and mean LVGFI was 34.7 ± 6.2%. A total of 174 incident CVD events were observed during the 21.9 years median follow-up. In multivariable adjusted models, 1-SD increase in LVGFI was significantly associated with lower hazard of HF, Hazard Ratio (HR) =0.55 95% confidence interval (CI) [0.40 - 0.74]; hard CVD, HR=0.74 95% CI [0.63 - 0.88] and all CVD events, HR=0.76 95% CI [0.65 -0.88]. (Table 1). LVGFI provided incremental predictive value for incident CVD compared to LV mass and LV ejection fraction alone.(Figure 1). Conclusions: LVGFI in early adulthood was associated with incident HF, hard CVD and all CVD events. In this longitudinal community study, LVGFI provided robust, independent and incremental predictive value for incident CVD events.

Z-Value of Mitral Annular Plane Systolic Excursion Is a Useful Indicator to Predict Left Ventricular Stroke Volume in Children: Comparing Longitudinal and Radial Contractions.

The purpose of our study was to explore the pumping mechanism of the left ventricle (LV) and to examine the role of longitudinal LV contraction in LV stroke volume (LVSV) compared to a radial LV contraction. We examined 890 consecutive children without structural heart disease including 395 patients with a history of Kawasaki disease (KD). We measured the mitral annular plane systolic excursion (MAPSE), the LV end-diastolic and end-systolic dimension (LVDd), the LV radial wall displacement (LVRWD) and the LV stroke volume (LVSV). The LVSV was determined by the Doppler method. The z-values of MAPSE, LVDd, LVRWD and LVSV were calculated by the mean values and standard deviations (SDs) based upon BSA every 0.1 m(2) . We evaluated the relationship between the z-LVSV and the geometrical factors. The z-value of the MAPSE was the most powerful determinant for the z-values of the LVSV of all of the geometrical factors (β = 0.36, P < 0.0001). However, the z-values of the LVRWD did not contribute to those of the LVSV. The longitudinal LV contraction contributes more to the LVSV than the radial LV contraction, even in subjects without heart failure. Evaluation of longitudinal LV contraction using the MAPSE z-value is useful for assessing global LV function in children with various body sizes.

Assessment of regional and global left ventricular function with electromechanical mapping: validation against MRI. A PRECISE substudy

Background Electromechanical mapping (EMM) of the left ventricle (LV) provides voltage and contractility information of the LV (based on linear local shortening, LLS). Although EMM parameters show excellent correlation with viability data by MRI, little information is available regarding performance of EMM for assessment of regional and global LV function. The purposes of our study were: a) to study the relationship between EMM (LLS) and wall motion by MRI in all segments and b) to correlate LV volumes and LVEF with both techniques.