The application of pulsed wave Doppler tissue imaging in the evaluation of cardiac function in cats with primary cardiomyopathy and disease states linked to specific cardiomyopathies in human-beings

Cardiac dysfunction is commonly identified in geriatric cats. Disease may be primary, typically hypertrophic cardiomyopathy (HCM), or may occur in association with a number of specific diseases, such as hyperthyroidism or hypertension.Doppler Tissue Imaging (DTI) techniques allow for the non-invasive assessment of myocardial dynamics. These techniques have previously demonstrated regional and global diastolic impairment in various forms of human cardiomyopathy and in cats with HCM.The aim of this study was to characterise the echocardiographic findings in healthy geriatric cats and to compare these to the changes seen in geriatric cats with primary cardiomyopathy and disease states linked to specific cardiomyopathies in human beings. It was predicted that from this it might be possible to derive disease specific cardiac changes. In addition, it may be possible to elucidate the affect of medication on disease processes.A total of 134 cats, aged eight years or above, were studied. Each cat underwent a conventional echocardiographic examination (two-dimensional, spectral Doppler, and M-mode) and a more advanced assessment of diastolic function (pulsed-wave Doppler tissue imaging [pw-DTI], colour M-mode propagation velocity and spectral Doppler assessment of the isovolumetric relaxation time). The cats were grouped according to either the disease process, or the diastolic filling pattern, and groups were then compared.Pulsed-wave DTI tracings (of both radial and longitudinal velocity) were successfully recorded from the feline myocardium. The repeatability of these measurements was assessed, and generally found to be comparable to the variability reported in human beings. There was no evidence that pw-DTI velocities are affected by age in a normal geriatric cat population. Furthermore, there was no significant difference in the relationship between pw-DTI velocities and age in cats within any of the disease groups studied, although there was some variation with heart rate (as assessed by the R-R interval). In addition, it was demonstrated that when grouped according to the transmitral diastolic flow pattern and the ratio of transmitral A-wave duration to pulmonary venous atrial reversal duration, the pwDTI flow pattern recorded from the apical four chamber view (at either the lateral aspect of the mitral annulus, or mid-lateral wall) was able to differentiate normal from impaired relaxation and pseudonormal flow patterns.Analysis of echocardiographic data demonstrated that there was an increase in the thickness of the basilar interventricular septum in the majority of cats studied. Compared to unaffected cats, cats with HCM had a decrease in the E' velocity (recorded by pw-DTI at the interventricular septum) and a tendency towards a decrease at the lateral aspect of the mitral annulus (recorded from the left apical fourchamber view). A similar decrease in the E' velocity in cats and people with HCM has been reported previously, and is thought to suggest diastolic dysfunction in affected individuals. Cats with chronic renal failure demonstrated some mild 2- dimensional and spectral Doppler abnormalities; however, no pw-DTI changes were detected in this group. The hyperthyroid cats demonstrated increased S' velocities, suggesting an increased inotropic state. In addition, the hyperthyroid cats demonstrated increased A' velocities, the cause of which was undetermined, but which may suggest mild diastolic dysfunction or an increase in atrial systolic function. A comparison of treated and untreated hyperthyroid cats was performed. This found that the treated hyperthyroid cats generally demonstrated less variation from the normal cats, compared to the untreated hyperthyroid cats, this may suggest that the use of carbimazole improves the function of the feline myocardium in thyrotoxic cardiomyopathy.This work, for the first time, uses novel ultrasound techniques to investigate the myocardial dynamics in normal geriatric cats, cats with primary hypertrophy and cats with a range of disease states linked to specific cardiomypathies in human beings. The use of these techniques has provided us with a new insight into these disease processes and has evaluated the use of this clinically applicable tool for the evaluation of feline myocardial dynamics

Severe Pneumococcal Pneumonia Causes Acute Cardiac Toxicity and Subsequent Cardiac Remodeling

Rationale: Up to one-third of patients hospitalized with pneumococcal pneumonia experience major adverse cardiac events (MACE) during or after pneumonia. In mice, Streptococcus pneumoniae caninvade themyocardium, induce cardiomyocyte death, and disrupt cardiac function following bacteremia, but it is unknown whether the same occurs in humans with severe pneumonia. Objectives: We sought to determine whether S. pneumoniae can (1) translocate the heart, (2) induce cardiomyocyte death, (3) causeMACE, and (4) induce cardiac scar formation after antibiotic treatment during severe pneumonia using a nonhuman primate (NHP) model. Methods: We examined cardiac tissue from six adult NHPs with severe pneumococcal pneumonia and three uninfected control animals. Three animals were rescued with antibiotics (convalescent animals). Electrocardiographic, echocardiographic, and serum biomarkers of cardiac damage were measured (troponin T, N-terminal pro-brain natriuretic peptide, and heart-type fatty acid binding protein). Histological examination included hematoxylin and eosin staining, immunofluorescence, immunohistochemistry, picrosirius red staining, and transmission electron microscopy. Immunoblots were used to assess the underlying mechanisms. Measurements and Main Results: Nonspecific ischemic alterations were detected by electrocardiography and echocardiography. Serum levels of troponin T and heart-type fatty acid binding protein were increased (P,0.05) after pneumococcal infection in both acutely ill and convalescent NHPs. S. pneumoniae was detected in the myocardium of all NHPs with acute severe pneumonia. Necroptosis and apoptosis were detected in the myocardium of both acutely ill and convalescent NHPs. Evidence of cardiac scar formation was observed only in convalescent animals by transmission electron microscopy and picrosirius red staining. Conclusions: S. pneumoniae invades the myocardium and induces cardiac injury with necroptosis and apoptosis, followed by cardiac scarring after antibiotic therapy, in anNHP model of severe pneumonia

Using a human cardiovascular-respiratory model to characterize cardiac tamponade and pulsus paradoxus

<p>Abstract</p> <p>Background</p> <p>Cardiac tamponade is a condition whereby fluid accumulation in the pericardial sac surrounding the heart causes elevation and equilibration of pericardial and cardiac chamber pressures, reduced cardiac output, changes in hemodynamics, partial chamber collapse, pulsus paradoxus, and arterio-venous acid-base disparity. Our large-scale model of the human cardiovascular-respiratory system (H-CRS) is employed to study mechanisms underlying cardiac tamponade and pulsus paradoxus. The model integrates hemodynamics, whole-body gas exchange, and autonomic nervous system control to simulate pressure, volume, and blood flow.</p> <p>Methods</p> <p>We integrate a new pericardial model into our previously developed H-CRS model based on a fit to patient pressure data. Virtual experiments are designed to simulate pericardial effusion and study mechanisms of pulsus paradoxus, focusing particularly on the role of the interventricular septum. Model differential equations programmed in C are solved using a 5^th-order Runge-Kutta numerical integration scheme. MATLAB is employed for waveform analysis.</p> <p>Results</p> <p>The H-CRS model simulates hemodynamic and respiratory changes associated with tamponade clinically. Our model predicts effects of effusion-generated pericardial constraint on chamber and septal mechanics, such as altered right atrial filling, delayed leftward septal motion, and prolonged left ventricular pre-ejection period, causing atrioventricular interaction and ventricular desynchronization. We demonstrate pericardial constraint to markedly accentuate normal ventricular interactions associated with respiratory effort, which we show to be the distinct mechanisms of pulsus paradoxus, namely, series and parallel ventricular interaction. Series ventricular interaction represents respiratory variation in right ventricular stroke volume carried over to the left ventricle via the pulmonary vasculature, whereas parallel interaction (via the septum and pericardium) is a result of competition for fixed filling space. We find that simulating active septal contraction is important in modeling ventricular interaction. The model predicts increased arterio-venous CO₂due to hypoperfusion, and we explore implications of respiratory pattern in tamponade.</p> <p>Conclusion</p> <p>Our modeling study of cardiac tamponade dissects the roles played by septal motion, atrioventricular and right-left ventricular interactions, pulmonary blood pooling, and the depth of respiration. The study fully describes the physiological basis of pulsus paradoxus. Our detailed analysis provides biophysically-based insights helpful for future experimental and clinical study of cardiac tamponade and related pericardial diseases.</p

Referencing echocardiographic measurements for premature and low-birth weight infants

Thesis (M. Tech. (Clinical Technology)) -- Central University of technology, Free State, 2012Introduction: Reference ranges for cardiac measurement are available for adults, children and term infants but the same cannot be said for preterm or small for gestational age (SGA) infants surviving as a result of modern intensive care units. No published data of reference ranges for preterm infants exists for the South African population. Infants with congenital heart disease are twice as likely to be small for their gestational age and these reference ranges may affect clinical management decisions, therapeutic response and prognosis of these neonates. The aim was thus to establish reference ranges for cardiac dimensions and functional values for preterm and low birth weight infants for central South Africa and compare them with international standards. Methods: A total of 290 infants of less than 34 weeks of age and weighing less than 2500g at birth were examined during a twelve month period by echocardiography during the first 0-28 days of life. The study assessed normative cardiac measurements divided in M-Mode, 2-D and functional measurement for these infants in 3 weight groups. Exclusion criteria were applied to any condition affecting the size and functionality of the cardiac system. The following dimensions were measured: Standard M-Mode values for the left ventricle, 2D measurements of valve mitral and tricuspid orifices, as well as functional assessments including Shortening fraction (SF %), Ejection fraction (EF %), and Muscle performance Index (MPI)-index of the Left and Right ventricle. Measurements were done by the leading edge methodology following the ASE recommendations. A longitudinal study was also done to examine changes in these indices over the first month- on day 14 and day 28 of life. Interobserver differences were calculated for the variability between measurements of a single scan- 25 babies were re-measured and produced good repeatability. Results: 290 infants were included to produce Referance ranges of measurements (means and standard deviations) for 3 weight groups namely: <0.999g, 1000-1499g, and 1500g – 2500g. The gestational age’s ranges between 26-38 weeks with a median of 31 weeks, gender distribution was almost equal with a slight female preponderance. Body surface area ranged from a minimum from 0.076 m² and a maximum of 0.184 m², the body weight ranged between a minimum of 690g and a maximum of 2500g with a median of 1360g. Discussion: The left ventricular diastolic and systolic, interventricular septum, posterior wall, aortic and left atrium dimensions showed a proportionate increase in diameter with an increase in body weight There were no differences in cardiac dimensions between Small for Gestational age” (SGA) versus “Average for Gestational age” (AGA). Gender and race played no role in any functional measurements or with the cardiac sizes. Weight correlated well with BSA and the data suggest that weight only can be used to develop tables for clinical use. Cardiac chambers increased with BSA and weight and functional measurements stayed the same throughout the weight groups. Systolic and global functions were remarkably similar and constant throughout weight categories. . The longitudinal study also confirmed that the values are applicable to all low birth weight infants up to 28 days of age. Differences existed between some of the average South African infant’s cardiac chambers and international values. The Inter Ventricular Septum (IVS) and Posterior Wall (PW) measured thicker and the Left Atrium larger. This could be due to numerous factors that should be investigated further. Conclusion: The study emphasized the profound effect of growth and weight gain on the cardiac structure and that population specific reference values should therefore be developed and used

Clinical Utility of Echocardiography in Former Preterm Infants with Bronchopulmonary Dysplasia.

BackgroundThe clinical utility of echocardiography for the diagnosis of pulmonary vascular disease (PVD) in former preterm infants with bronchopulmonary dysplasia (BPD) is not established. Elevated pulmonary vascular resistance (PVR) rather than pulmonary artery pressure (PAP) is the hallmark of PVD. We evaluated the utility of echocardiography in infants with BPD in diagnosing pulmonary hypertension and PVD (PVR &gt;3 Wood units&nbsp;×&nbsp;m2) assessed by cardiac catheterization.MethodsA retrospective single center study of 29 infants born ≤29&nbsp;weeks of gestational age with BPD who underwent cardiac catheterization and echocardiography was performed. PVD was considered present by echocardiography if the tricuspid valve regurgitation jet peak velocity was &gt;2.9&nbsp;m/sec, post-tricuspid valve shunt systolic flow velocity estimated a right ventricular systolic pressure &gt;35&nbsp;mm Hg, or systolic septal flattening was present. The utility (accuracy, sensitivity, and positive predictive value [PPV]) of echocardiography in the diagnosis of PVD was tested. Subgroup analysis in patients without post-tricuspid valve shunts was performed. Echocardiographic estimations of right ventricular pressure, dimensions, function, and pulmonary flow measurements were evaluated for correlation with PVR.ResultsThe duration between echocardiography and cardiac catheterization was a median of 1&nbsp;day (interquartile range, 1-4&nbsp;days). Accuracy, sensitivity, and PPV of echocardiography in diagnosing PVD were 72%, 90.5%, and 76%, respectively. Accuracy, sensitivity, and PPV increased to 93%, 91.7%, and 100%, respectively, when infants with post-tricuspid valve shunts were excluded. Echocardiography had poor accuracy in estimating the degree of PAP elevation by cardiac catheterization. In infants without post-tricuspid valve shunts, there was moderate to good correlation between indexed PVR and right ventricular myocardial performance index (rho&nbsp;=&nbsp;0.89, P&nbsp;=&nbsp;.005), systolic to diastolic time index (0.84, P&nbsp;&lt;&nbsp;.001), right to left ventricular diameter ratio at end systole (0.66, P&nbsp;=&nbsp;.003), and pulmonary artery acceleration time (0.48, P&nbsp;=&nbsp;.05).ConclusionsEchocardiography performs well in screening for PVD in infants with BPD and may be diagnostic in the absence of a post-tricuspid valve shunt. However, cardiac catheterization is needed to assess the degree of PAP elevation and PVR. The diagnostic utility of echocardiographic measurements that correlate with PVR should be evaluated prospectively in this patient population

Towards standardization of echocardiography for the evaluation of left ventricular function in adult rodents : a position paper of the ESC Working Group on Myocardial Function

This work was supported by AIRC IG grant 2016 19032 to S.Z.; FEDER through Compete 2020 –Programa Operacional Competitividade E Internacionalização(POCI), the project DOCNET (norte-01-0145-feder-000003), supported by Norte Portugal regional operational programme (norte 2020), under the Portugal 2020 partnership agreement, through the European Regional Development Fund (ERDF), the project NETDIAMOND (POCI-01-0145-FEDER-016385), supported by European Structural And Investment Funds, Lisbon’s regional operational program 2020 to I.P.F.; grants from FSR-FNRS, FRC (Cliniques Universitaires Saint-Luc) and from Action de Recherche Concertée (UCLouvain) to C.B., E.P.D. and L.B; the ERA-Net-CVD project MacroERA,01KL1706, FP7-Homage N° 305507, and IMI2-CARDIATEAM (N° 821508)to S.H.,the DZHK (German Centre for Cardiovascular Research) and the German Ministry of Research and Education (BMBF)to F.W., T.E. and L.C., the Netherlands Cardiovascular Research Initiative, an initiative with support of the Dutch Heart Foundation, CVON2016-Early HFPEF, 2015-10, CVON She-PREDICTS, grant 2017-21, CVON Arena-PRIME, 2017-18, Flemish Research FoundationFWO G091018N and FWO G0B5930N to S.H.; Federico II University/Ricerca di Ateneo grant to C.G..T.; the European Research Area Networks on Cardiovascular Diseases (ERA-CVD) [LYMIT-DIS 2016, MacroERA], Fonds Wetenschappelijk Onderzoek [1160718N] to I.C; the Deutsche Forschungsgemeinschaft (DFG TH903/20-1, KFO311), the Transregio-SFB INST 95/15641 and the EU Horizon 2020 project Cardioregenix (GA 825670)to T.TPeer reviewedPostprin

Early diagnosis of cardiovascular diseases in workers: role of standard and advanced echocardiography

Cardiovascular disease (CVD) still remains the main cause of morbidity and mortality and consequently early diagnosis is of paramount importance. Working conditions can be regarded as an additional risk factor for CVD. Since different aspects of the job may affect vascular health differently, it is important to consider occupation from multiple perspectives to better assess occupational impacts on health. Standard echocardiography has several targets in the cardiac population, as the assessment of myocardial performance, valvular and/or congenital heart disease, and hemodynamics. Three-dimensional echocardiography gained attention recently as a viable clinical tool in assessing left ventricular (LV) and right ventricular (RV), volume, and shape. Two-dimensional (2DSTE) and, more recently, three-dimensional speckle tracking echocardiography (3DSTE) have also emerged as methods for detection of global and regional myocardial dysfunction in various cardiovascular diseases, and applied to the diagnosis of subtle LV and RV dysfunction. Although these novel echocardiographic imaging modalities have advanced our understanding of LV and RV mechanics, overlapping patterns often show challenges that limit their clinical utility. This review will describe the current state of standard and advanced echocardiography in early detection (secondary prevention) of CVD and address future directions for this potentially important diagnostic strategy

The use of magnetic resonance imaging and proton spectroscopy to identify critical tissues in dogs with Duchenne Muscular Dystrophy for future assessment of therapeutic intervention : a pilot study

Duchenne's Muscular Dystrophy is a debilitating disease that affects skeletal and cardiac muscle of 1 in 5000 male births. In the last thirty years, the gene responsible for the encoding of Dystrophin has been identified, sequenced and the variations of mutations described. There remains a void in the successful treatment of the disease although corticosteroid use has proven useful in delaying progression. Novel therapies are produced in the categories of virus-mediated gene delivery and stem cells, but evaluating their efficacy is hindered by an inability to contemporaneously assess the changes in muscle. The purpose of this pilot study was to characterize the changes in skeletal and cardiac muscle in a clinically advanced population of dogs affected with Duchenne Muscular Dystrophy. Using traditional sequences, delayed gadolinium enhancement, novel sequences and spectroscopy, changes in the investigated muscle were characterized. By establishing the differences between affected and unaffected dogs, the long-term goal of this body of work is to characterize these changes longitudinally and design a non-invasive method for tissue assessment as novel treatments are trialed.Includes bibliographical reference

Transient Hypertrophic Cardiomyopathy in Premature Infants

The purpose of this study is to examine whether iatrogenic hypertrophic cardiomyopathy (HCM) in premature infants might be induced by routine neonatal therapies including the administration of hyperalimentation, dexamethasone, and/or insulin infusion. Infants with gestational age \u3c 32 weeks and birth weight \u3c 1250 grams were studied. Echocardiographic and metabolic analyses were performed before 48 hours of age at enrollment, and again at one, two, three, and five weeks thereafter. Eleven patients were studied with a median gestational age of 26 weeks (range 24-29 weeks) and median birth weight of 804 grams (range 609-1230 grams). All eleven subjects received hyperalimentation, five received dexamethasone, and two received both dexamethasone and an exogenous insulin infusion. The ratio of interventricular septal to left ventricular posterior wall thickness increased significantly from 1.15±0.06 at enrollment to 1.51±0.06 (p\u3c0.05) during the third week of life, consistent with the diagnosis of HCM. This ratio returned to a normal value of 1.17±0.1 by the fifth week of life. C-peptide excreted in the urine peaked during the fourth week of life at 253±99 μg/g creatinine, and a peak in circulating insulin levels to 19±4 μU/ml occurred during the third week of life. Both the excreted C-peptide and circulating insulin levels decreased by the end of the fifth week of life. All results are expressed as the mean±SEM. This preliminary data suggest that the development of a transient hypertrophic cardiomyopathy occurs in premature infants, and appears to resolve as caloric intake, insulin production, and circulating insulin levels decrease