Long-axis View Research Articles

Quantification of Mouse Heart Left Ventricular Function, Myocardial Strain, and Hemodynamic Forces by Cardiovascular Magnetic Resonance Imaging.

Mouse models have contributed significantly to understanding genetic and physiological factors involved in healthy cardiac function, how perturbations result in pathology, and how myocardial diseases may be treated. Cardiovascular magnetic resonance imaging (CMR) has become an indispensable tool for a comprehensive in vivo assessment of cardiac anatomy and function. This protocol shows detailed measurements of mouse heart left ventricular function, myocardial strain, and hemodynamic forces using 7-Tesla CMR. First, animal preparation and positioning in the scanner are demonstrated. Survey scans are performed for planning imaging slices in various short- and long-axis views. A series of prospective ECG-triggered short-axis (SA) movies (or CINE images) are acquired covering the heart from apex to base, capturing end-systolic and end-diastolic phases. Subsequently, single-slice, retrospectively gated CINE images are acquired in a midventricular SA view, and in 2-, 3-, and 4-chamber views, to be reconstructed into high-temporal resolution CINE images using custom-built and open-source software. CINE images are subsequently analyzed using dedicated CMR image analysis software. Delineating endomyocardial and epicardial borders in SA end-systolic and end-diastolic CINE images allows for the calculation of end-systolic and end-diastolic volumes, ejection fraction, and cardiac output. The midventricular SA CINE images are delineated for all cardiac time frames to extract a detailed volume-time curve. Its time derivative allows for the calculation of the diastolic function as the ratio of the early filling and atrial contraction waves. Finally, left ventricular endocardial walls in the 2-, 3-, and 4-chamber views are delineated using feature-tracking, from which longitudinal myocardial strain parameters and left ventricular hemodynamic forces are calculated. In conclusion, this protocol provides detailed in vivo quantification of the mouse cardiac parameters, which can be used to study temporal alterations in cardiac function in various mouse models of heart disease.

A new method for facilitating ultrasound-guided in-plane cannulation of the subclavian vein: a randomized clinical trial

The objective of this study was to propose a new method for facilitating needle-beam alignment ultrasound-guided in-plane catheterization of the subclavian vein (SCV). Three hundred patients were recruited, and ultrasound examination of the SCV was performed. Then, the patients were divided into two groups and SCV catheterization was performed: ultrasound-guided catheterization with the aiming method (group A) and ultrasound-guided catheterization with needle guide (group NG). The success rate, insertion time, number of skin breaks, number of needle redirections, needle visibility and rate of mechanical complications were documented and compared for each procedure. To depict the optimum long-axis view of the SCV, there was a 30° ± 7.3° angle (rotation) between the long axis of the ultrasound probe and the clavicle, while there was a 39° ± 7.4° angle (tilt) between the ultrasound beam plane and the right chest wall. The aiming method was associated with fewer skin breaks [(mean (IQR): 1 (1–1) times vs 1 (1–2) times, P = 0.009], a shorter time to cannulation [(mean (IQR): 39 (32–48.5) s vs 48 (44–54.8) s, P = 0.000] and more needle redirections [(mean (IQR): 0 (0–1) vs 0 (0–0), P = 0.000]. There were no differences between group A and group NG in the overall success rate, first puncture success rate, needle visibility or mechanical complication rate. In conclusion, during ultrasound-guided in-plane catheterization of the SCV, the aiming method provides comparable needle-beam alignment with a lower cannulation time than the needle guide technique.

Longitudinal Tracking of Cardiac Alterations Among Young Adults with SARS‐CoV‐2

BackgroundThe novel SARS‐CoV‐2 virus inflicts far‐reaching health decrements, both directly and through secondary inflammatory stimulation. To date, there is little information regarding the effects of COVID‐19 on the heart after infection, especially among young healthy adults.PurposeWe sought to determine whether contracting SARS‐CoV‐2 affects cardiac function in young, otherwise healthy adults and whether these alterations recede after testing positive for SARS‐CoV‐2.MethodsTransthoracic echocardiography was performed on 7 subjects with SARS‐CoV‐2 (3F/4M, 21±1y, 24±2 kgᐧm‐1) who tested positive 3‐4 weeks prior to baseline testing followed by 1‐month and 2‐month follow‐up testing. A parasternal long‐axis view was utilized to measure septal and left ventricular posterior wall thickness, left ventricular volume, and left ventricular outflow tract dimensions. A four‐chamber view was utilized to measure mitral and tricuspid valve, left ventricular, and pulmonary vein function. Data are mean±SD.ResultsStroke volume (Baseline: 44±11ml, 1‐month: 42±13ml, 2‐month: 54±12ml) and stroke index (Baseline: 24±6ml/m^2, 1‐month: 22±7ml/m^2, 2‐month: 29±6ml/m^2) were elevated at 2‐month follow‐up (p<0.05). Left ventricular posterior wall thickness was lower at 1‐month follow‐up (Baseline: 1.56±0.10cm, 1‐month: 1.44±0.08cm, 2‐month: 1.47±0.13cm) (p<0.05). Pulmonary vein systolic flow decreased at 2‐month follow‐up (Baseline: 0.64±0.04m/s, 1‐month: 0.58±0.07m/s, 2‐month: 0.49±0.08m/s) (p<0.05).ConclusionsThe current findings suggest subclinical alterations to the myocardium of young adults who have recently contracted SARS‐CoV‐2. Further, these results may be reflective of a myocardium which is recovering months following initial infection.

Stabilization of red blood cell aggregation evaluation using short-axis view of vein of ultrasound

Red blood cell (RBC) aggregation is the reversible adhesion of RBCs among themselves. We previously reported a positive correlation between blood glucose level and the degree of RBC aggregation (the brightness of the B-mode image). In the present study, we investigated the contribution to the brightness according to the deviation from the central axis in measurements along with the long-axis view of the vein. The results show that the brightness changed significantly for a slight change in the lateral position in the short-axis image. We found that the stability of the measurements was not guaranteed in the long-axis view and estimated the correct analysis window range for the short-axis view.

Ultrasound-guided arterial catheterization.

Ultrasonography facilitates arterial catheterization compared to traditional palpation techniques, especially in small arteries. For successful catheterization without complications, practitioners should be familiar with the anatomic characteristics of the artery and ultrasound-guided techniques. There are two approaches for ultrasound-guided arterial catheterization: the short-axis view out-of-plane approach and the long-axis view in-plane approach. There are several modified techniques and tips to facilitate ultrasound-guided arterial catheterization. This review deals with the anatomy relevant to arterial catheterization, several methods to improve success rates, and decrease complications associated with arterial catheterization.

A deep learning approach for the automatic recognition of prosthetic mitral valve in echocardiographic images

The first step in the automatic evaluation of the cardiac prosthetic valve is the recognition of such valves in echocardiographic images. This research surveyed whether a deep convolutional neural network (DCNN) could improve the recognition of prosthetic mitral valve in conventional 2D echocardiographic images. An efficient intervention to decrease the misreading rate of the prosthetic mitral valve is required for non-expert cardiologists. This intervention could serve as a section of a fully-automated analysis chain, alleviate the cardiologist's workload, and improve precision and time management, especially in an emergent situation. Additionally, it might be suitable for pre-labeling large databases of unclassified images. We, therefore, introduce a large publicly-available annotated dataset for the purpose of prosthetic mitral valve recognition. We utilized 2044 comprehensive non-stress transthoracic echocardiographic studies. Totally, 1597 patients had natural mitral valves and 447 patients had prosthetic valves. Each case contained 1 cycle of echocardiographic images from the apical 4-chamber (A4C) and the parasternal long-axis (PLA) views. Thirteen versions of the state-of-the-art models were independently trained, and the ensemble predictions were performed using those versions. For the recognition of prosthetic mitral valves from natural mitral valves, the area under the receiver-operating characteristic curve (AUC) made by the deep learning algorithm was similar to that made by cardiologists (0.99). In this research, EfficientNetB3 architecture in the A4C view and the EfficientNetB4 architecture in the PLA view were the best models among the other pre-trained DCNN models.

ACTIVE CONTOUR MODELS-BASED SEGMENTATION OF LEFT VENTRICLE IN ULTRASOUND IMAGES FOR DIFFERENT AXES VIEWS

Segmentation of the left ventricle in ultrasound images for viewing through different axes is a critical aspect. This paper proposes the development of novel active contour models with shape constraint to segment the left ventricle in three different axis views of the ultrasound images. The shapes observed in all the axis views of the left ventricle were not similar. According to the cardiac cycle, the valve opening in the end-diastolic phase influenced the left ventricle segmentation; hence, a shape constraint was embedded in the active contour model to keep ventricle’s shape, especially in the Apical long-axis view and Apical four-chamber view. Furthermore, for different axes views, diverse active contour models were proposed to fit each situation. The shape constraint in each function for different views exhibited a specific shape during the function iteration. In order to speed up the algorithm evolution, previous results were used for the initialization of the present active contour. We evaluated the proposed method on 57 patients with three different views: Apical long-axis view, Apical four-chamber view and Short-axis view at the papillary muscle level and obtained the Dice similarity coefficients of [Formula: see text], [Formula: see text] and [Formula: see text] and the Hausdorff distance metrics of [Formula: see text], [Formula: see text] and [Formula: see text], respectively. The qualitative and quantitative evaluations showed an advantage of our method in terms of segmentation accuracy.

Novel Echocardiographic Algorithm for Right Ventricular Mass Quantification: Cardiovascular Magnetic Resonance and Clinical Prognosis Validation

Right ventricular hypertrophy (RVH) provides a key remodeling index alterable by pulmonary hypertension. Although echocardiography commonly integrates linear wall thickness and chamber dimensions to quantify left ventricular remodeling, the utility of an equivalent right ventricular (RV)-based approach is unknown. This was a retrospective analysis of 200 patients undergoing transthoracic echocardiography and cardiac magnetic resonance (CMR) within 30days (median= 3days; interquartile range, 15days), stratified by echocardiography-quantified pulmonary artery systolic pressure (<35, 35 to <55, 55 to <75, or ≥75mm Hg). Echocardiographic assessment included RV linear dimensions in parasternal long-axis and apical four-chamber views and wall thicknesses in parasternal long-axis, four-chamber, and subcostal views. Subcostal wall thickness was integrated with chamber diameters to calculate RV mass, which was tested in relation to CMR-quantified RV mass and all-cause mortality. Echocardiography-based quantification of all linear dimensions was feasible in 95% of patients (190 of 200). RV wall thicknesses in all orientations increased in relation to pulmonary artery systolic pressure (P<.001) and was greater among patients with, versus those without, CMR-evidenced RVH (P<.001 for all). Correlations between echocardiography and CMR were greatest for RV basal diameter (r=0.73), RV subcostal wall thickness (r=0.71), and global RV mass (r=0.82; P<.001 for all). Echocardiography-derived global RV mass cutoffs were established in a derivation cohort and tested in a validation cohort. Results demonstrated good sensitivity and specificity (75.5% and 74.0%, respectively) in relation to CMR-quantified RVH. During follow-up (median, 4.2years), 18% of patients (n=36) died. Echocardiography-evidenced RVH (hazard ratio, 1.98; 95% CI, 1.09-3.88; P=.048) conferred similar mortality risk compared with RVH on CMR (hazard ratio, 2.41; 95% CI, 1.22-4.78; P=.01). Echocardiography-quantified RV parameters provide a robust index of RV afterload. Global RV mass calculated using a novel echocardiographic formula based on readily available linear indices yields good diagnostic performance for CMR-evidenced RVH and confers increased mortality risk.

Suprasternal long-axis echocardiographic view revealing a tongue-shaped mass in the aortic arch.

Suprasternal long-axis echocardiographic view revealing a tongue-shaped mass in the aortic arch.

Atrial Fibrillation in Valvular Heart Disease.

Rheumatic heart disease results in significant remodeling of the atria that provides the milieu for maintaining atrial fibrillation. Some electrical remodeling is reversible and hence early intervention may prove useful. Active screening for atrial fibrillation in high-risk subset and instituting anticoagulation may reduce the devastating complications that follow. Age older than 50years, NYHA functional class II symptoms, left atrial dimension>4.0cm on echocardiogram in parasternal long-axis view, and gradients across the mitral valve>10mm Hg are clinical indicators that identify the high-risk subset. Ablation strategy in this population may differ compared with the nonvalvular group.

LV non-compaction in patients with coarctation of the aorta: prevalence and effects on cardiac function

Left ventricular non-compaction has been associated with heart failure, arrhythmia, thromboembolism and sudden death. The prevalence of non-compaction in patients with coarctation of the aorta and its clinical significance remains unknown, although obstructive left heart disease is common in patients with non-compaction. We sought to evaluate the prevalence of left ventricular non-compaction in patients with repaired aortic coarctation as well as its effect on left ventricular size and systolic function. In total, 268 patients (Mean age 26 (inter-quartile range 21-37) years, 63% male) undergoing cardiac magnetic resonance imaging for clinical follow-up were included from three tertiary centres for adult congenital heart disease. Clinical data was obtained from medical records and correlated with ventricular volumes and function. Left ventricular non-compaction was defined as a diastolic non-compacted:compacted dimension ratio >2.3 in the worst affected segment on a long-axis view. Left ventricular non-compaction was present in 8.2% of patients with repaired coarctation. Left ventricular end-diastolic volumes and stroke volumes were significantly higher in patients with non-compaction compared to those without. There were no significant differences in ventricular mass or ejection fraction in these two groups. Left ventricular non-compaction is relatively common in patients with repaired coarctation of the aorta and correlates with increased left ventricular end-diastolic volumes.

Point-of-care ultrasound during the COVID-19 pandemic: A multidisciplinary approach between intensivists and echocardiographers.

PurposeThe coronavirus disease‐2019 (COVID‐19) led to a large influx of critically ill patients and altered echocardiography laboratory workflow. We developed a point‐of‐care ultrasound (POCUS) first approach to patients requiring echocardiography and describe our workflow and findings.MethodsWe performed a single‐center retrospective analysis of all POCUS studies performed on critically ill patients with COVID‐19. Sonography was performed by intensivists, uploaded and archived, and rapidly reviewed by echocardiographers. We evaluated each study based on the number of views obtained. Additionally, we provide a description of the workflow during the COVID‐19 surge at a tertiary care hospital in New York City.ResultsFifty patients had POCUS studies performed by intensivists and reviewed by echocardiographers obviating the need for sonographer‐performed studies. Of the 48 cardiac POCUS studies, 17% of patients had 4 of 4 standard views available while 53% had 3 of 4 standard views. The parasternal long‐axis view was obtained on 81%, subxiphoid view on 79%, apical 4‐chamber view on 71%, and parasternal short‐axis view on 63% of patients.ConclusionsOur POCUS workflow allowed intensivists to perform cardiac sonography for rapid bedside diagnosis of pathology with immediate interpretation performed by echocardiographers. At least 3 views were obtained in the majority of cases.

Reduced left atrial strain in magnetic resonance imaging is associated with abnormal P-waves in patients after acute myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): ReForM-B-Program Background Abnormal P-wave terminal force in lead V1 (PTFV1) is associated with atrial remodeling. The relationship between PTFV1 and atrial function after acute myocardial injury is insufficiently understood and may be elucidated by detailed feature tracking (FT) strain analysis of cardiac magnetic resonance images (CMR). Purpose We investigated the relationship between PTFV1 and left atrial (LA) strain (measured by CMR) in a patient cohort presenting with acute myocardial infarction (MI). Methods 56 patients with acute MI underwent CMR within 3-5 days after MI. PTFV1 was measured as the product of negative P-wave amplitude and duration in lead V1 (Fig. A). A PTFV1 &amp;gt;4000 ms*µV was defined as abnormal. CMR cine data were retrospectively analyzed using a dedicated FT software. LA strain (ε) and strain rate (SR) for atrial reservoir ([εs]; [SRs]), conduit ([εe]; [SRe]) and booster function ([εa]; [SRa]) were measured in two long-axis views (Fig. A). Results Patients with abnormal PTFV1 had significantly reduced LA conduit function εe and SRe (Fig. B + D). There was a significant negative correlation between the extent of PTFV1 and both εe and SRe (Fig. C + E). In univariate and multivariate regression models, both PTFV1 and age predicted atrial conduit function. In contrast, multiple clinical co-factors had no significant influence on εe (Table). Interestingly, linear regression models revealed only mild dependency of PTFV1 on conventional parameters of cardiac function such as left ventricular ejection fraction (p = 0.059; R²(adj.)=0.047), and no dependency on structural parameters such as LA area (p = 0.639; R²(adj.)=0.016), or LA fractional area change (p = 0.825; R²(adj.)=0.020). Conclusion Abnormal PTFV1 was associated with reduced LA function independent from numerous clinical co-factors in patients presenting with acute myocardial infarction. Table N = 56 Linear Regression Analysis Multiple Linear Regression Analysis (R2 (adj.)=0.376, p = 0.016) Variable B 95% CI P value R2 (adj.) B 95% CI P value PTFV1 [µV*ms] -1.628 17085.298 to 27210.854 0.013 0.092 -1.315 -2.614 to -0.016 0.047 Age [y] -425.775 24985.168 to 54634.995 0.002 0.145 -610.815 -982.78 to -238.849 0.001 Body mass indes [kg/m2] -185.653 -3259.187 to 47020.775 0.671 -0.015 -506.096 -1327.357 to 315.165 0.219 Creatinine kinase [U/l] -1.571 14806.991 to 24842.272 0.121 0.027 -1.791 -3.72 to 0.138 0.067 Male sex -893.28 10701.206 to 23504.066 0.802 -0.017 4275.631 -3842.517 to 12393.78 0.292 Estimated glomerular filtration rate [ml/min/1.73m2] 88.617 -4564.177 to 21395.361 0.202 0.012 -163.981 -331.343 to 3.381 0.054 Systolic blood pressure [mmHg] -2.001 14045.786 to 22037.253 0.095 0.038 29.331 -108.243 to 166.906 0.668 nt-pro brain natriuretic peptide [pg/ml] 24.629 -4060.804 to 30920.828 0.716 -0.016 1.015 -1.778 to 3.809 0.466 Univariate and multivariate linear regression models for left atrial conduit strain Abstract Figure

Closed-chest measurement of diastolic and systolic shear wave speed to assess myocardial stiffness

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Research Foundation Flanders (FWO): grant 1211620N TTW – Dutch Heart Foundation partnership program "Earlier recognition of cardiovascular diseases": project number 14740 Background Echocardiographic shear wave elastography (SWE) encompasses all ultrasound techniques tracking shear wave (SW) motion in the cardiac wall, of which the propagation speed is linked to the intrinsic mechanical properties. SWs can be induced naturally, for example by valve closure, or externally by using an acoustic radiation force (ARF). Although the latter is technically more demanding, it enables instantaneous stiffness assessment throughout the entire cardiac cycle (fig. a). However, it is unknown how factors such as cardiac loading and contractility, next to intrinsic mechanical properties, affect ARF-based SW speeds. Purpose We performed transthoracic SWE measurements in pigs to study the effects of hemodynamic alterations, inotropic state and myocardial infarction (MI) on diastolic and systolic SW speeds. Methods Different cardiac conditions were considered in three pigs: (i) baseline (BL), (ii) preload decrease (PD), (iii) afterload increase (AI), (iv) preload increase (PI), (v) administration of dobutamine (DOB), (vi) BL2, (vii) MI through 60-100 min. occlusion of the LAD and (viii) 40 min. reperfusion (REP). For each condition, transthoracic high frame rate ARF-based SWE acquisitions were taken in a parasternal long-axis view with a research ultrasound system. SWs were induced in the septum at 34 Hz during 1.5 s to track SW speeds throughout the cardiac cycle (fig. a&amp;b). Systolic and diastolic SW speeds were determined from the 10% highest and lowest median values per condition, respectively. Left ventricular pressure-volume (PV) loops were recorded to estimate end-diastolic pressure (EDP), end-systolic pressure (ESP) and passive chamber stiffness (dPdV). dPdV was determined as the slope of the tangent to the fitted end-diastolic PV relationship at mean ED volume. Linear regressions and Pearson’s correlation coefficients were computed. Results Diastolic SW speed was correlated to EDP for conditions with changes in loading, and to dPdV for conditions with changes in chamber stiffness (fig. c). Both relationships were significant, with a moderate positive correlation for EDP (R = 0.48, p = 0.02) and a strong positive correlation for dPdV (R = 0.76, p &amp;lt; 0.01). Furthermore, the observed change in diastolic SW speed was smaller when altering EDP compared to dPdV (0.4 m/s vs. 1.0 m/s). For systolic SW speed, very strong positive correlations were found with ESP (R = 0.91, p &amp;lt; 0.01), and with dPdV (R = 0.81, p &amp;lt; 0.01) in fig. d. Conclusion This study shows that both diastolic and systolic SW speed are related to passive chamber stiffness. Moreover, loading also influenced systolic SW speed and, to a lesser extent, diastolic SW speed, presumably because of material nonlinearity. Systolic SW speed is linked to contractility as well. Thus, while SWs after valve closure occur at a certain moment in the cardiac cycle, the timing of ARF-based SWs can be chosen such to assess specific aspects of the cardiac (structural and functional) status. Abstract Figure.

Aortic root longitudinal strain by speckle-tracking echocardiography predicts progressive aortic root dilation in Marfan syndrome patients

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Ministry of Science, Innovation and Universities; Instituto de Salud Carlos III Introduction In Marfan syndrome (MFS) patients reduced longitudinal strain of the ascending aorta (AAo) as measured by applying feature-tracking on cine cardiac magnetic resonance (CMR) images predicts aortic root dilation and aortic events during the follow-up. Speckle-tracking is well established for cardiac deformation assessment but proximal aorta applications are challenging due to limited wall thickness and substantial cardiac motion. Moreover, echocardiography is widely used in the clinical assessment aortic diseases. Purpose We aimed to test a speckle-tracking tool for root longitudinal strain analysis in terms of comparison with CMR-derived AAo longitudinal strain and reproducibility and as predictor of dilation in MFS patients. Methods Thirty-five MFS patients diagnosed by original GHENT criteria, with maximum aortic root diameter of 45 mm and free from previous aortic dissection or cardiac/aortic surgery and non-severe aortic regurgitation were consecutive enrolled and followed-up. CMR and echocardiography were performed less than 2 months apart. Baseline and final aortic root diameter were measured on CMR images. To quantify aortic root cyclic elongation by echocardiography, two regions of interests were manually created covering both walls in a parasternal long-axis view and tracked along the cardiac cycle (Figure 1). Longitudinal strain was computed as the average of maximum increase in relative distance of several sub-regions covering both walls. CMR-derived AAo longitudinal strain was available in 29 patients. Intra-observer reproducibility was tested in 15 patients via intraclass correlation coefficient (ICC) for single-rater absolute agreement. Results Aortic root longitudinal strain by echocardiography was mildly related to CMR-derived AAo longitudinal strain (R = 0.27) and was larger compared to CMR-derived values (16.2 ± 6.0 vs 11.3 ± 4.3). Reproducibility was high, with ICC of 0.811, R = 0.802, p &amp;lt; 0.001. After a mean follow up of 76 ± 13 months, aortic root diameter grew in 20 patients with a rate of 0.29± 0.24 mm/year. Overall mean growth-rate was 0.87 ± 0.33 mm/year. In multivariable analysis corrected for age and baseline aortic root diameter, baseline longitudinal strain by echocardiography was independently and inversely related to progressive dilation (p = 0.033). Conclusions The measurement of aortic root longitudinal strain by speckle-tracking echocardiography is feasible. Aortic root longitudinal strain is an independent predictor of progressive dilation in MFS patients. This may permit the improvement of risk-stratification in aortic diseases in large scale studies. Abstract Figure 1

The influence of hemodialysis-induced preload changes on the propagation speed of natural shear waves

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation - Flanders (FWO) Background Shear wave elastography (SWE) is a novel ultrasound technique based on the detection of transverse waves travelling through the myocardium using high frame rate echocardiography. The propagation speed of these shear waves is dependent on the stiffness of the myocardium. Previous studies have shown the potential of SWE for the non-invasive assessment of myocardial stiffness. It is unclear, however, if preload changes lead to measurable changes in the shear wave propagation speed in the left ventricle. In patients undergoing hemodialysis, the volume status is acutely changed. In this way, the effect of preload changes on shear wave speed can be assessed. Purpose The aim of this study was to explore the influence of preload changes on end-diastolic shear wave propagation speed. Methods Until now, 6 patients (age: 80[53-85] years; female: n = 2) receiving hemodialysis treatment were included. Echocardiographic images were taken before and every hour during a 4 hour hemodialysis session. Left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (average frame rate: 1016[941-1310] Hz). Standard echocardiography was performed with a conventional ultrasound machine. Shear waves were visualized on tissue acceleration maps by drawing an M-mode line along the interventricular septum. Shear wave propagation speed after mitral valve closure (MVC) was calculated by measuring the slope of the wave pattern on the acceleration maps (Figure A). Results Over the course of hemodialysis, the systolic (141[135-156] mmHg vs. 165[105-176] mmHg; p = 0.35 among groups) and diastolic blood pressure (70[66-75] mmHg vs. 82[63-84] mmHg; p = 0.21 among groups), heart rate (56[54-73] bmp vs. 57[50-67] bpm; p = 0.76 among groups), E/A ratio (1.6[0.7-1.8] vs. 1.2[0.6-1.4]; p = 0.43 among groups) and E/e’ (14[9-15] vs. 9[8-13]; p = 0.24 among groups ) remained the same. The ultra-filtrated volumes are shown in Figure B. The shear wave propagation speed after MVC gradually decreased during hemodialysis (6.7[5.4-9.7] m/s vs. 4.4[3.6-9.0] m/s; p = 0.04 among groups) (Figure C). There was a moderate negative correlation between shear wave speed and the ultra-filtrated volume (r=-0.63; p &amp;lt; 0.01) (Figure D). Conclusion The shear wave propagation speed at MVC significantly decreased over the course of hemodialysis and correlated to the ultra-filtrated volume. These results indicate that alterations in left ventricular preload affect the speed of shear waves at end-diastole. End-diastolic shear wave speed might therefore be a potential novel parameter for the evaluation of the left ventricular filling state. More patients will be included in the future to further explore these findings. Abstract Figure.

Natural shear wave propagation speed is influenced by both changes in myocardial structural properties as well as loading conditions

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation - Flanders (FWO) Background Shear wave elastography (SWE) is a promising tool for the non-invasive assessment of myocardial stiffness. It is based on the evaluation of the propagation speed of shear waves by high frame rate echocardiography. These waves can be induced by for instance mitral valve closure (MVC) and the speed at which they travel is related to the instantaneous stiffness of the myocardium. Myocardial stiffness is defined by the local slope of the stress-strain relation and can therefore be altered by both changes in structural properties of the myocardium as well as loading conditions. Purpose The aim of this study was to investigate how changes in myocardial structural properties as well as loading conditions affect shear wave speed after MVC. Methods Until now, 8 pigs (weight: 33.6 ± 5.4 kg) were included. The following interventions were performed: 1) preload was reduced by balloon occlusion of the vena cava inferior, 2) afterload was increased by balloon occlusion of descending aorta, 3) preload was increased by intravenous administration of 500 ml of saline and 4) ischemia/reperfusion injury (I/R injury) was induced in the septal wall by balloon occlusion of the LAD for 90 min. with subsequent reperfusion for 40 min. Echocardiographic and left ventricular pressure recordings were simultaneously obtained during each intervention. Left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (average frame rate: 1279 ± 148 Hz). Shear waves were visualized on tissue acceleration maps by drawing an M-mode line along the interventricular septum. Shear wave propagation speed after MVC was calculated by assessing the slope of the wave pattern on the tissue acceleration map (Figure A). Results The change in left ventricular end-diastolic pressure (LVEDP) and shear wave speed after MVC between baseline and each intervention are shown in Figure B and C, respectively. Preload reduction resulted in significant lower LVEDP compared to baseline (p &amp;lt; 0.01), while the other loading changes did not have a significant effect. Shear wave speed after MVC significantly increased by afterload and preload increase (p &amp;lt; 0.01). I/R injury resulted in increased shear wave speed (p &amp;lt; 0.01) without significantly altering LVEDP. There was a good positive correlation between the change in LVEDP and the change in shear wave speed induced by loading changes (r = 0.76; p &amp;lt; 0.001) (Figure D). However, the correlation became less strong if data of I/R injury was taken into account as well (r = 0.63; p &amp;lt; 0.001). Conclusion Our results suggest that SWE is capable to characterize myocardial tissue properties and besides has the potential as a novel method for the estimation of left ventricular filling pressures. However, in the presence of structural changes of the myocardium, care should be taken when estimating filling pressures based on shear wave propagation speed. Abstract Figure.

Bioprosthetic Valve Thrombosis Associated With COVID-19 Infection

HomeCirculation: Cardiovascular ImagingVol. 14, No. 5Bioprosthetic Valve Thrombosis Associated With COVID-19 Infection Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissionsDownload Articles + Supplements ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toSupplementary MaterialsFree AccessCase ReportPDF/EPUBBioprosthetic Valve Thrombosis Associated With COVID-19 Infection Steven A. Alexander, MD, Icilma V. Fergus, MD and Stamatios Lerakis, MD, PhD Steven A. AlexanderSteven A. Alexander Steven A. Alexander, MD, Icahn School of Medicine at Mt Sinai, 1 Gustave L. Levy Pl, Box 1030, New York, NY 10029. Email E-mail Address: [email protected] https://orcid.org/0000-0002-0719-9177 The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY. Search for more papers by this author , Icilma V. FergusIcilma V. Fergus The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY. Search for more papers by this author and Stamatios LerakisStamatios Lerakis https://orcid.org/0000-0001-7487-1990 The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY. Search for more papers by this author Originally published5 Feb 2021https://doi.org/10.1161/CIRCIMAGING.120.012118Circulation: Cardiovascular Imaging. 2021;14:e012118Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: February 5, 2021: Ahead of Print Obstructive bioprosthetic valve thrombosis is a rare but potentially devastating complication.1 Coronavirus disease 2019 (COVID-19) predisposes patients to both venous and arterial thrombosis.2–4 The impact this may have on patients with endovascular prosthetic material is unknown. We report a case of obstructive bioprosthetic aortic valve thrombosis in a patient hospitalized with COVID-19.A 79-year-old woman presented to clinic with a 2-month history of dyspnea and cough. Four months prior, she was treated for a type A aortic dissection with hemiaortic arch and bioprosthetic aortic valve replacement. She initially recovered but was hospitalized 2 months later with COVID-19 pneumonia. Laboratory evaluation at that time showed elevated C-reactive protein (79.8 mg/dL), activated partial thromboplastin time (44.2 s), fibrinogen (489 mg/dL), and D-dimer (2.14 μg/mL). She was treated with convalescent plasma and received prophylactic low molecular weight heparin. Her hospital course was uncomplicated, and she was discharged on apixaban 5 mg twice daily.A transthoracic echocardiogram showed prosthetic aortic valve stenosis with a peak aortic velocity of 3.8 m/s, increased from 2.2 m/s postoperatively. A transesophageal echocardiogram revealed markedly thickened bioprosthetic valve leaflets (Figure 1, Movie I in the Data Supplement). A computed tomography scan showed hypoattenuated leaflet thickening involving all 3 valve leaflets consistent with leaflet thrombosis (Figure 2).Download figureDownload PowerPointFigure 1. Prosthetic aortic valve thrombosis. Biplane transesophageal echocardiogram (TEE) at the level of the aortic valve showing marked thickening of the bioprosthetic aortic valve leaflets, consistent with leaflet thrombosis.Download figureDownload PowerPointFigure 2. Hypoattenuated leaflet thickening of the prosthetic aortic valve.A, Short axis and (B) long-axis views of the aortic valve on computed tomography showing hypoattenuated leaflet thickening (HALT; white arrows). Ao indicates aorta; LA, left atrium; PA, pulmonary artery; and RA, right atrium.The patient was admitted to the hospital, started on an unfractionated heparin infusion, and bridged to warfarin with a goal internationalized normalized ratio of 2.5 to 3.5. Follow-up transthoracic echocardiogram performed 3 months later showed improvement of her aortic valve gradient back to baseline (Figure 3).Download figureDownload PowerPointFigure 3. Prosthetic aortic valve gradient before and after 3 mo of warfarin.A, The peak aortic valve velocity was 3.8 m/s before treatment and (B) decreased to 2.2 m/s after treatment.To our knowledge, this is the first report of prosthetic aortic valve thrombosis associated with COVID-19 infection. This case reminds us that patients with prosthetic heart valves and endovascular devices may be at particular risk of thrombotic complications from COVID-19. Health care providers should have a high index of suspicion for such complications and consider diagnostic imaging when appropriate. Further research is needed to determine the optimal anticoagulation strategy for both the prevention and treatment of bioprosthetic valve thrombosis in the setting of COVID-19 infection.Sources of FundingNone.Supplemental MaterialData Supplement Movie IDisclosures None.FootnotesThe Data Supplement is available at https://www.ahajournals.org/doi/suppl/10.1161/CIRCIMAGING.120.012118.Steven A. Alexander, MD, Icahn School of Medicine at Mt Sinai, 1 Gustave L. Levy Pl, Box 1030, New York, NY 10029. Email steven.[email protected]org

Reliability and reproducibility of cardiac MRI quantification of peak exercise function with long-axis views.

The conventional approach to cardiac magnetic resonance (CMR) involving breath holds, electrocardiography-gating, and acquisition of a short-axis (SAX) image stack, introduces technical and logistical challenges for assessing exercise left ventricular (LV) function. Real-time, free-breathing CMR acquisition of long-axis (LAX) images overcomes these issues and also enables assessment of global longitudinal strain (GLS). We evaluated the reliability of a free-breathing LAX approach compared to the standard SAX approach and the reproducibility of free-breathing LAX. LV SAX (contiguous stack) and LAX (two-chamber and four-chamber) 3T CMR cine images were acquired four times within one scan in 32 women with cardiovascular risk factors (56±10 years, 28±4 kg/m2) as follows: 1) resting, gated-segmented, end-expiration breath-hold; 2) resting, real-time, free-breathing; 3) test-retest set of resting, real-time, free-breathing; 4) peak exercise (incremental-to-maximum, in-magnet, stepper test), real-time, free-breathing. A second scan was performed within one week in a subset (n = 5) to determine reproducibility of peak exercise measures. Reliability and agreement of the free-breathing LAX approach with the conventional SAX approach were assessed by intraclass correlation coefficient (ICC) and Bland-Altman plots, respectively. Normal control GLS reserve was also acquired in a separate set of 12 young, healthy control women (25±4 years, 22±2 kg/m2) for comparison. Comparisons of LV volumes and function among all techniques at rest had good-to-excellent reliability (ICC = 0.80–0.96), and excellent reliability between peak exercise free-breathing LAX and SAX evaluations (ICC = 0.92–0.96). Higher resting heart rates with free-breathing acquisitions compared to breath-hold (mean difference, limits of agreement: 5, 1–12 beats per minute) reduced reliability for cardiac output (ICC = 0.67–0.79). Reproducibility of the free-breathing LAX approach was good-to-excellent at rest and peak exercise (ICC = 0.74–0.99). GLS exercise reserve was impaired in older women at cardiovascular risk compared to young healthy women (-4.7±2.3% vs -7.4±2.1%, p = 0.001). Real-time, free-breathing CMR with LAX evaluation provides a reliable and reproducible method to assess rest and peak exercise cardiac function, including GLS.

Prevalence and characteristics of mitral valve prolapse in military young adults in Taiwan of the CHIEF Heart Study

The prevalence of mitral valve prolapse (MVP) among middle- and older-aged individuals is estimated to be 2–4% in Western countries. However, few studies have been conducted among Asian individuals and young adults. This study included a sample of 2442 consecutive military adults aged 18–39 years in Hualien, Taiwan. MVP was defined as displacement of the anterior or posterior leaflet of the mitral valve to the mid portion of the annular hinge point > 2 mm in the parasternal long-axis view of echocardiography. Cardiac chamber size and wall thickness were measured based on the latest criteria of the American Society of Echocardiography. The clinical features of participants with MVP and those without MVP were compared using a two-sample t test, and the cardiac structures were compared using analysis of covariance with adjustment for body surface area (BSA). Eighty-two participants were diagnosed with MVP, and the prevalence was 3.36% in the overall population. Compared with those without MVP, participants with MVP had a lower body mass index (kg/m2) (24.89 ± 3.70 vs. 23.91 ± 3.45, p = 0.02) and higher prevalence of somatic symptoms related to exercise (11.0% vs. 4.9%, p = 0.02) and systolic click in auscultation (18.3% vs. 0.6%, p < 0.01). In addition, participants with MVP had greater left ventricular mass (gm) and smaller right ventricular wall thickness (mm) and dimensions (mm) indexed by BSA than those without MVP (149.12 ± 35.76 vs. 155.38 ± 36.26; 4.66 ± 0.63 vs. 4.40 ± 0.68; 26.57 ± 3.99 vs. 25.41 ± 4.35, respectively, all p-values < 0.01). In conclusion, the prevalence and clinical features of MVP in military young adults in Taiwan were in line with those in Western countries. Whether the novel MVP phenotype found in this study has any pathological meaning needs further investigation.