Nanobody-coupled microbubbles as novel molecular tracer.

Camelid-derived single-domain antibody-fragments (~15kDa), called nanobodies, are a new class of molecular tracers that are routinely identified with nanomolar affinity for their target and that are easily tailored for molecular imaging and drug delivery applications. We hypothesized that they are well-suited for the design of targeted microbubbles (μBs) and aimed to develop and characterize eGFP- and VCAM-1-targeted μBs. Anti-eGFP (cAbGFP4) and anti-VCAM-1 (cAbVCAM1-5) nanobodies were site-specifically biotinylated in bacteria.

Integrated backscatter for the in vivo quantification of supraphysiological vitamin D(3)-induced cardiovascular calcifications in rats.

Cardiovascular calcifications are frequently found in the aging population and are independent predictors of future cardiovascular events. Integrated backscatter (IB) of ultrasound reflectivity can easily quantify calcifications. For this purpose, 30 male Wistar rats received 25,000 IU/kg/day of vitamin D(3) (group 1, n = 8), 18,800 IU/kg/day (group 2, n = 8), or injections with the vehicle only (group 3, n = 14), for 10 weeks.

Evaluation of contractile function and inotropic reserve with tissue velocity, strain and strain rate imaging in streptozotocin-induced diabetes.

Aims: The aim of the present study was to evaluate left ventricular (LV) function and contractile reserve (CR) with Doppler myocardial imaging (DMI) in a small animal model for type 1 diabetes.

Methods And Results: Cardiac function was assessed in anaesthetized Wistar rats 6 and 8 weeks after injection of 60 mg/kg of streptozotocin. At 6 weeks of diabetes, colour DMI echocardiography was performed at rest and during incremental dosages of dobutamine (5, 10, 20 microg/kg/min).

Recommendations for the practice of echocardiography in infective endocarditis.

Echocardiography plays a key role in the assessment of infective endocarditis (IE). It is useful for the diagnosis of endocarditis, the assessment of the severity of the disease, the prediction of short- and long-term prognosis, the prediction of embolic events, and the follow-up of patients under specific antibiotic therapy. Echocardiography is also useful for the diagnosis and management of the complications of IE, helping the physician in decision-making, particularly when a surgical therapy is considered.

Impact of global left ventricular afterload on left ventricular function in asymptomatic severe aortic stenosis: a two-dimensional speckle-tracking study.

Aims: The present study sought to assess the effect of global left ventricular (LV) afterload on LV myocardial systolic function in patients with aortic stenosis (AS) and preserved LV ejection fraction.

Methods And Results: We prospectively examined the LV myocardial deformation (i.e.

Prognostic effect of long-axis left ventricular dysfunction and B-type natriuretic peptide levels in asymptomatic aortic stenosis.

In aortic stenosis (AS), the increased afterload results in progressive structural and functional changes that precede the development of symptoms. We hypothesized that the detection of abnormalities in left ventricular long-axis function could identify patients with asymptomatic AS at increased risk of events. We prospectively examined the outcome of 126 patients with asymptomatic AS who underwent a comprehensive echocardiographic examination, including tissue Doppler imaging.

Effect of high-intensity ultrasound-targeted microbubble destruction on perfusion and function of the rat heart assessed by pinhole-gated SPECT.

Although ultrasound-targeted microbubble destruction (UTMD) has been shown to induce bioeffects, UTMD is still desirable for therapeutic applications. Therefore, we studied the effects of UTMD on perfusion and function of the rat heart, assessed by (99m)Tc-MIBI pinhole-gated SPECT (Ph-gSPECT) compared with biomarker release and histopathology. Fifty-two male Wistar rats were studied.

Analysis of regional wall motion during contrast-enhanced dobutamine stress echocardiography: effect of contrast imaging settings.

Aims: Myocardial contrast perfusion echocardiography (MCE) allows simultaneous assessment of perfusion and function. However, low frame rate during MCE may reduce the viewer's ability to discern contractile dysfunction. This study sought to compare MCE and left ventricular opacification (LVO) settings with regard to wall motion abnormalities (WMA) at rest and during dobutamine stress echocardiography (DSE).

Dose dependency and reversibility of serotonin-induced valvular heart disease in rats.

Serotonergic drugs may lead to valvular heart disease in humans and more recently also in rats. Although clinical data suggest that dose dependency and reversibility after drug cessation might occur, proof of this is lacking. For that purpose, a total of 106 rats were prospectively enrolled: 22 control animals and 7 groups of 12 rats that received daily subcutaneous serotonin injections (5, 10, 20, 30, 40, 50 and 60 mg/kg respectively) for 12 weeks.

Comparison of contrast enhanced three dimensional echocardiography with MIBI gated SPECT for the evaluation of left ventricular function.

Background: In clinical practice and in clinical trials, echocardiography and scintigraphy are used the most for the evaluation of global left ejection fraction (LVEF) and left ventricular (LV) volumes. Actually, poor quality imaging and geometrical assumptions are the main limitations of LVEF measured by echocardiography. Contrast agents and 3D echocardiography are new methods that may alleviate these potential limitations.

Myocardial contractile reserve during exercise predicts left ventricular reverse remodelling after cardiac resynchronization therapy.

Aims: Lack of response to cardiac resynchronization therapy (CRT) may be due to the presence of significant amount of scar or fibrotic tissue at myocardial level. This study sought to investigate the potential impact of myocardial contractile reserve as assessed during exercise echocardiography on left ventricular (LV) reverse remodelling (decrease in LV end-systolic volume > or =15% after 6 months of CRT).

Methods And Results: Fifty-one consecutive patients with heart failure underwent exercise Doppler echocardiography before CRT implantation to assess global contractile reserve and local contractile reserve (assessed by two-dimensional speckle tracking) in the region of the LV pacing lead.

Cyproheptadine prevents pergolide-induced valvulopathy in rats: an echocardiographic and histopathological study.

Serotonergic drugs, such as pergolide, have been associated with the development of cardiac valvular myxoid thickening and regurgitation in humans and more recently in rats. These effects are potentially mediated by the 5-hydroxytryptamine (5-HT)(2B) receptor (5-HT(2B)R). Therefore, we sought to determine whether cyproheptadine, a 5-HT(2B)R antagonist, might prevent toxic valvulopathy in an animal model of pergolide-induced valvular heart disease.

Role of echocardiography in toxic heart valvulopathy.

The notion that drugs can induce valvular heart disease (VHD) has occurred since the 1960s and has received a lot of attention in recent years. This review focuses on different aspects of this distinct valvulopathy in seven sections: (i) historical background, (ii) drug-induced VHD, is this a real entity?, (iii) its morphological and echocardiographic features, (iv) drugs associated with VHD, (v) the influence of cumulative drug dose and risk factors, (vi) the natural course of toxic valvulopathy, and (vii) practical recommendations when using potential valvulopathic drugs.

Impact of contractile reserve on acute response to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) provides benefit for congestive heart failure, but still 30% of patients failed to respond to such therapy. This lack of response may be due to the presence of significant amount of scar or fibrotic tissue at myocardial level. This study sought to investigate the potential impact of myocardial contractile reserve as assessed during exercise echocardiography on acute response following CRT implantation.

Echocardiographic and histological assessment of age-related valvular changes in normal rats.

Aging is associated with morphologic and functional alterations of the rat's left ventricle. However, the time-course of valvular function and morphology in normal aging rats has not yet been studied. For this purpose, 30 male Wistar rats (318 +/- 5g, 10 weeks old) underwent serial echocardiograms for 58 weeks under sodium pentobarbital 50 mg/kg IP anesthetization followed by necropsy.

Importance of left ventricular longitudinal function and functional reserve in patients with degenerative mitral regurgitation: assessment by two-dimensional speckle tracking.

Background: The aim of this study was to determine whether two-dimensional speckle tracking of longitudinal myocardial deformation can detect limited contractile reserve during exercise in patients with asymptomatic degenerative mitral regurgitation (MR).

Methods: Seventy-one patients with degenerative MR and normal left ventricular (LV) ejection fractions underwent quantitative exercise echocardiography.

Results: Compared with 23 normal subjects matched for age and sex, LV volumes were greater in patients with MR.

Effects of valve replacement for aortic stenosis on mitral regurgitation.

We aimed to prospectively and quantitatively assess the effects of aortic valve replacement (AVR) for aortic stenosis (AS) on mitral regurgitation (MR) and to examine the determinants of the changes in MR. Fifty-two patients with AS scheduled for AVR were included if holosystolic MR not being considered for replacement or repair was detected. MR was quantified using the proximal isovelocity surface area method before and 8 +/- 4 days after surgery.

Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats.

Unlabelled: The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with streptozotocin-induced diabetic rats using contrast echocardiography.

Effects of eythropoietin administration on mitral regurgitation and left ventricular remodeling in heart failure patients.

The effects of erythropoietin administration on mitral regurgitation in patients with congestive heart failure have not yet been examined. After 2 months, erythropoietin treatment results in a significant reduction in left ventricular volumes and mitral regurgitation severity and improves hemodynamics.

Doppler myocardial imaging in the diagnosis of early systolic left ventricular dysfunction in diabetic rats.

Aim: To find out if Doppler myocardial imaging (DMI) can detect early signs of left ventricular (LV) dysfunction in a rat model of diabetic cardiomyopathy.

Methods: Eight control and 12 Streptozotocin (STZ)-induced diabetic rats underwent transthoracic echocardiography with high-resolution technology at baseline and 2, 4, 8, 12, and 16 weeks after STZ injection. Radial function was analysed using conventional M-mode, and velocity, strain and strain rate imaging.

Impact of anesthesia on valvular function in normal rats during echocardiography.

Anesthetic agents have different effects on hemodynamic and cardiac functional parameters. The influence of these changes on valvular function has not been studied in small animals. For this purpose, 48 male Wistar rats were divided into three equal groups.

Dynamic left ventricular dyssynchrony contributes to B-type natriuretic peptide release during exercise in patients with systolic heart failure.

Aims: Plasma B-type natriuretic peptide (BNP) is an emerging biomarker in heart failure. In this setting, the extent of left ventricular (LV) dyssynchrony contributes to exercise symptoms. Whether exercise-induced changes in LV dyssynchrony might be a trigger of BNP release has never been investigated.