Abstract Background The hydrodynamic cause of systolic anterior motion of the mitral valve (SAM) is unresolved. Objectives This study hypothesized that echocardiographic vector flow mapping, a new ...echocardiographic technique, would provide insights into the cause of early SAM in obstructive hypertrophic cardiomyopathy (HCM). Methods We analyzed the spatial relationship of left ventricular (LV) flow and the mitral valve leaflets (MVL) on 3-chamber vector flow mapping frames, and performed mitral valve measurements on 2-dimensional frames in patients with obstructive and nonobstructive HCM and in normal patients. Results We compared 82 patients (22 obstructive HCM, 23 nonobstructive HCM, and 37 normal) by measuring 164 LV pre- and post-SAM velocity vector flow maps, 82 maximum isovolumic vortices, and 328 2-dimensional frames. We observed color flow and velocity vector flow posterior to the MVL impacting them in the early systolic frames of 95% of obstructive HCM, 22% of nonobstructive HCM, and 11% of normal patients (p < 0.001). In both pre- and post-SAM frames, we measured a high angle of attack >60° of local vector flow onto the posterior surface of the leaflets whether the flow was ejection (59%) or the early systolic isovolumic vortex (41%). Ricochet of vector flow, rebounding off the leaflet into the cul-de-sac, was noted in 82% of the obstructed HCM, 9% of nonobstructive HCM, and none (0%) of the control patients (p < 0.001). Flow velocities in the LV outflow tract on the pre-SAM frame 1 and 2 mm from the tip of the anterior leaflet were low: 39 and 43 cm/s, respectively. Conclusions Early systolic flow impacts the posterior surfaces of protruding MVL initiating SAM in obstructive HCM.
In this randomized, controlled trial, the use of pirfenidone in patients with idiopathic pulmonary fibrosis led to a slower rate of loss in forced vital capacity than the use of placebo.
Idiopathic ...pulmonary fibrosis is a chronic, progressive, and fatal lung disease that is characterized by irreversible loss of lung function.
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Although periods of transient clinical stability may be observed, continued progression of the disease is inevitable.
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The prognosis is poor, with a 5-year survival rate that is similar to the rates for several cancers.
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Pirfenidone is an oral antifibrotic therapy that has been evaluated for the treatment of idiopathic pulmonary fibrosis in three phase 3, randomized, controlled trials. One of these trials was conducted in Japan and involved 275 patients. It was followed by two multinational studies, Clinical Studies . . .
Heart disease remains a leading cause of death worldwide. Previous research has indicated that the dynamics of the cardiac left ventricle (LV) during diastolic filling may play a critical role in ...dictating overall cardiac health. Hence, numerous studies have aimed to predict and evaluate global cardiac health based on quantitative parameters describing LV function. However, the inherent complexity of LV diastole, in its electrical, muscular, and hemodynamic processes, has prevented the development of tools to accurately predict and diagnose heart failure at early stages, when corrective measures are most effective. In this work, it is demonstrated that major aspects of cardiac function are reflected uniquely and sensitively in the optimization of vortex formation in the blood flow during early diastole, as measured by a dimensionless numerical index. This index of optimal vortex formation correlates well with existing measures of cardiac health such as the LV ejection fraction. However, unlike existing measures, this previously undescribed index does not require patient-specific information to determine numerical index values corresponding to normal function. A study of normal and pathological cardiac health in human subjects demonstrates the ability of this global index to distinguish disease states by a straightforward analysis of noninvasive LV measurements.
The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by four-dimensional echocardiography (4DE).
Latex balloons were sewn into the left ...ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-dimensional echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30-70 ml and correlated with sonomicrometry data.
In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P <0.001). Bland-Altman analyses showed slight overestimations of echo-derived GLS, GCS, 2DE-LVEF and 3DE-LVEF over sonomicrometry values (bias = 2.88, bias = 3.99, bias = 3.37, bias = 2.78, respectively). Furthermore, there is better agreement between GCS, 4D LVEF and sonomicrometry values compared with GLS and 2D LVEF.
Four-dimensional echocardiography accurately assesses LV function. GCS derived by 4DE is a potential alternative parameter to quantify LV systolic function.
This study compared the variability of 3D echo derived circumferential and longitudinal strain values computed from vendor-specific and vendor-independent analyses of images acquired using ultrasound ...systems from different vendors.
Ten freshly harvested porcine hearts were studied. Each heart was mounted on a custom designed phantom and driven to simulate normal cardiac motion. Cardiac rotation was digitally controlled and held constant at 5°, while pumped stroke volume (SV) ranged from 30-70ml. Full-volume image data was acquired using three different ultrasound systems from different vendors. The image data was analyzed for longitudinal and circumferential strains (LS, CS) using both vendor-specific and vendor-independent analysis packages.
Good linear relationships were observed for each vendor-specific analysis package for both CS and LS at the mid-anterior segment, with correlation coefficients ranging from 0.82-0.91 (CS) and 0.86-0.89 (LS). Comparable linear regressions were observed for results determined by a vendor independent program (CS: R = 0.82-0.89; LS: R = 0.86-0.89). Variability between analysis packages was examined via a series of ANOVA tests. A statistical difference was found between vendor-specific analysis packages (p<0.001), while no such difference was observed between ultrasound systems when using the vendor-independent program (p>0.05).
Circumferential and longitudinal regional strain values differ when quantified by vendor-specific analysis packages; however, this variability is mitigated by use of a vendor-independent quantification method. These results suggest that echocardiograms acquired using different ultrasound systems could be meaningfully compared using vendor-independent software.
the etiology of ventricular dysfunction in adult congenital heart disease (ACHD) is not well understood. Diffuse fibrosis is a likely common final pathway and is quantifiable using MRI.
patients with ...ACHD (n=50) were studied with cardiac MRI to quantify systemic ventricular volume and function and diffuse fibrosis. The fibrosis index for a single midventricular plane of the systemic ventricle was quantified by measuring T1 values for blood pool and myocardium before and after administration of gadolinium (0.15 mmol/kg) and then adjusted for hematocrit. Results were compared to healthy volunteers (normal controls, n=14) and patients with acquired heart failure (positive controls, n=4). Patients studied (age, 37±12 years; female sex, 40%) included 11 with a systemic right ventricle (RV), 17 with tetralogy of Fallot, 10 with cyanosis, and 12 with other lesions. The fibrosis index was significantly elevated in patients with ACHD compared to normal controls (31.9±4.9% versus 24.8±2.0%; P=0.001). Values were highest in patients with a systemic RV (35.0±5.8%; P<0.001) and those who were cyanotic (33.7±5.6%; P<0.001). The fibrosis index correlated with end-diastolic volume index (r=0.60; P<0.001) and ventricular ejection fraction (r=-0.53; P<0.001) but not with age or oxygen saturation in patients who were cyanotic. Late gadolinium enhancement did not account for the differences seen.
patients with ACHD have evidence of diffuse, extracellular matrix remodeling similar to patients with acquired heart failure. The fibrosis index may facilitate studies on the mechanisms and treatment of myocardial fibrosis and heart failure in these patients.
Echocardiography with speckle tracking is a novel, angle-independent technique for assessing global and regional cardiac function. Normal data on longitudinal strain have been reported for human ...fetuses. The aim of this study was to define circumferential left ventricular (LV) strain in a normal fetal population.
Singleton fetuses between 17 and 42 weeks in gestational age with no adverse maternal health issues or fetal abnormalities were studied. Regional and averaged cardiac strain were measured using syngo Velocity Vector Imaging software.
Data from 81 fetuses were analyzed (mean gestational age, 29.2 ± 5.7 weeks). Overall, average midventricular circumferential strain was 18.7 ± 3.3%, LV longitudinal strain was 15.2 ± 2.7%, and right ventricular longitudinal strain was 16.0 ± 3.3%, with no correlation with gestational age.
This is the first study to report normal fetal LV circumferential strain. These data may be useful as a reference for assessing fetal cardiac function. The retrospective study design and relatively low frame rates used in this study were important limitations.
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