Echocardiographic integrated backscatter for detecting progression and regression of aortic valve calcifications in rats.
; ; et al
in Cardiovascular Ultrasound (2013), 11(1), 4
ABSTRACT: BACKGROUND: Calcification is an independent predictor of mortality in calcific aortic valve disease (CAVD). The aim of this study was to evaluate the use of non-invasive, non-ionizing ... [more ▼]
ABSTRACT: BACKGROUND: Calcification is an independent predictor of mortality in calcific aortic valve disease (CAVD). The aim of this study was to evaluate the use of non-invasive, non-ionizing echocardiographic calibrated integrated backscatter (cIB) for monitoring progression and subsequent regression of aortic valvular calcifications in a rat model of reversible renal failure with CAVD, compared to histology. METHODS: 28 male Wistar rats were prospectively followed during 21 weeks. Group 1 (N=14) was fed with a 0.5% adenine diet for 9 weeks to induce renal failure and CAVD. Group 2 (N=14) received a standard diet. At week 9, six animals of each group were killed. The remaining animals of group 1 (N=8) and group 2 (N=8) were kept on a standard diet for an additional 12 weeks. cIB of the aortic valve was calculated at baseline, 9 and 21 weeks, followed by measurement of the calcified area (Ca Area) on histology. RESULTS: At week 9, cIB values and Ca Area of the aortic valve were significantly increased in the adenine-fed rats compared to baseline and controls. After 12 weeks of adenine diet cessation, cIB values and Ca Area of group 1 decreased compared to week 9, while there was no longer a significant difference compared to age-matched controls of group 2. CONCLUSIONS: cIB is a non-invasive tool allowing quantitative monitoring of CAVD progression and regression in a rat model of reversible renal failure, as validated by comparison with histology. This technique might become useful for assessing CAVD during targeted therapy. [less ▲]Detailed reference viewed: 13 (3 ULg)
Integrated backscatter for the in vivo quantification of supraphysiological vitamin D(3)-induced cardiovascular calcifications in rats.
; ; et al
in Cardiovascular Toxicology (2011), 11(3), 244-52
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 ... [more ▼]
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. Echocardiographic calibrated IB (cIB) was measured and calculated at baseline and after 10 weeks, followed by ex vivo micro-CT and histopathology of the aortic valve, ascending aorta, and myocardium. After 10 weeks, the mean cIB value of the aortic valve was significantly higher for vitamin D(3)-dosed animals compared to controls. The mean cIB value of the ascending aorta and the myocardium was also significantly higher in group 1 compared to group 3. In vivo IB results were confirmed by ex vivo micro-CT and histopathology. In conclusion, IB is a non-ionizing, feasible, and reproducible tool to quantify cardiovascular calcifications in an in vivo rat model. The integration of IB in the standard echocardiographic examination for the quantification of cardiovascular calcifications could be useful for serial evaluation of treatment efficacy and for prognosis assessment. [less ▲]Detailed reference viewed: 10 (3 ULg)
Impact of global left ventricular afterload on left ventricular function in asymptomatic severe aortic stenosis: a two-dimensional speckle-tracking study.
Lancellotti, Patrizio ; ; Magne, Julien et al
in European Journal of Echocardiography (2010), 11(6), 537-543
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 ... [more ▼]
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. <br />Methods and results: We prospectively examined the LV myocardial deformation (i.e. longitudinal, radial, and circumferential) by two-dimensional speckle tracking in 173 patients with asymptomatic severe AS. Thirty-eight patients (22%) had lowflow as determined by a low stroke volume index (35 mL/m2). By multivariable analysis, four variables emerged as independently associated with low-flow AS: peak Ea velocity (P 1⁄4 0.01), left atrial area index (P 1⁄4 0.017), global LV afterload (P 1⁄4 0.024), and circumferential myocardial deformation (P 1⁄4 0.04). Forty-nine patients (28%) had an increased global LV afterload (5 mmHg mL/m2). Systemic arterial compliance (P 1⁄4 0.001), circumferential myocardial deformation (P 1⁄4 0.024), and left atrial area index (P 1⁄4 0.04) were independently associated with increased global LV load in multivariable analysis. <br />Conclusion: In asymptomatic patients with severe AS, LV ejection fraction markedly underestimates the extent of myocardial sys- tolic impairment. Intrinsic myocardial dysfunction is particularly common in patients with increased global LV after- load, and especially in the subset of patients with low-flow AS. [less ▲]Detailed reference viewed: 28 (4 ULg)
Analysis of regional wall motion during contrast-enhanced dobutamine stress echocardiography: effect of contrast imaging settings.
; ; et al
in European Journal of Echocardiography (2009), 10(8), 956-60
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 ... [more ▼]
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). Methods and results: In 50 patients scheduled for coronary angiography and with poor baseline image quality, MCE and LVO were performed during DSE. Regional wall motion was assessed and inter-observer agreement was determined for each imaging modality. The endocardial border score index was similar for both modalities. The wall motion score index (WMSCI) at peak stress using MCE was well correlated with WMSCI obtained with LVO (r2 = 0.9, P < 0.001). However, WMSCI at peak stress was underestimated by MCE (1.66 ± 0.58 with DSE-LVO vs. 1.535 ± 0.50 with DSE-MCE; P < 0.001). Inter-observer agreement on the presence of WMA was 0.65 for MCE and 0.67 for LVO at peak stress. Conclusion: Myocardial contrast perfusion echocardiography provides equal endocardial border delineation compared with LVO modality. Although the inter-observer agreement is slightly higher with LVO compared with MCE, it is not significantly different with MCE at peak stress. Despite the similar improvement in endocardial border delineation, LVO settings allow the detection of more WMA than MCE at peak stress, leading to a significantly higher accuracy for the detection of ischaemia in patients suspected of coronary artery disease when only wall motion is taken into account. [less ▲]Detailed reference viewed: 22 (4 ULg)
Comparison of contrast enhanced three dimensional echocardiography with MIBI gated SPECT for the evaluation of left ventricular function
; ; et al
in Cardiovascular Ultrasound (2009), 7Detailed reference viewed: 15 (3 ULg)
Impact of contractile reserve on acute response to cardiac resynchronization therapy
Moonen, Marie ; ; et al
in Cardiovascular Ultrasound (2008), 6(65),
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 ... [more ▼]
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. Methods: Fifty-one consecutive patients with heart failure (LV ejection fraction 27% ± 5%, 67% ischemic cardiomyopathy) underwent exercise Doppler echocardiography before CRT implantation to assess global contractile reserve (improvement in LV ejection fraction) and local contractile reserve in the region of the LV pacing lead (assessed by radial strain using speckle tracking analysis). Responders were defined by an increase in stroke volume ≥15% after CRT. Results: Compared with nonresponders, responders (25 patients) showed a greater exercise-induced increase in LV ejection fraction, a higher degree of mitral regurgitation and a significant extent of LV dyssynchrony. The presence of contractile reserve was directly related to the acute increase in stroke volume (r = 0.48, p<0.001). Baseline myocardial deformation as well as contractile reserve in the LV pacing lead region was greater in responders during exercise than in nonresponders (p<0.0001). Conclusions: Heart failure patients referred to CRT have less chance of improving under therapy if they have no significant mitral regurgitation, no LV dyssynchrony and no contractile myocardial recruitment at exercise. [less ▲]Detailed reference viewed: 47 (3 ULg)
Effects of valve replacement for aortic stenosis on mitral regurgitation.
; ; et al
in American Journal of Cardiology (2008), 102(10), 1378-82
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 ... [more ▼]
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. Mitral valvular deformation parameters did not change significantly, but the mitral effective regurgitant orifice (ERO) and regurgitant volume decreased from 11 +/- 6 mm(2) to 8 +/- 6 mm(2) and from 20 +/- 10 ml to 11 +/- 9 ml, respectively (both p <0.0001). Using multiple linear regression analysis, preoperative severity of MR, mitral leaflet coaptation height, and end-diastolic volume decrease were independently associated with postoperative reduction in MR, whereas changes in mitral valve morphology after surgery were not. MR etiology did not predict the reduction in MR. In conclusion, the decrease in MR observed in most patients after AVR is associated with the magnitude of acute left ventricular reverse remodeling. As the reduction in left ventricular systolic pressure contributes to the decrease in regurgitant volume, the preoperative quantitative assessment of MR should best be performed by measurement of the ERO. [less ▲]Detailed reference viewed: 31 (2 ULg)
Dynamic left ventricular dyssynchrony contributes to B-type natriuretic peptide release during exercise in patients with systolic heart failure.
Lancellotti, Patrizio ; ; Pierard, Luc
in Europace : European Pacing, Arrhythmias, and Cardiac Electrophysiology : Journal of the Working Groups on Cardiac Pacing, Arrhythmias, and Cardiac Cellular Electrophysiology of the European Society of Cardiology (2008), 10(4), 496-501
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 ... [more ▼]
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. METHODS AND RESULTS: Fifty-seven patients with systolic LV dysfunction underwent quantitative analysis of BNP, mitral regurgitation (MR), and dyssynchrony at rest and during exercise. None had inducible ischaemia on perfusion imaging. By multiple regression analysis, end-systolic volume index (P < 0.0001), effective regurgitant orifice (ERO) (P < 0.001), and E/Ea (P = 0.002) emerged as independent determinants of BNP at baseline (R(2) = 0.67). Exercise induced a significant rise in BNP levels (P < 0.0001). In multivariate analysis, a smaller change in systolic blood pressure (P = 0.04), a larger increase in ERO (P = 0.017), and in systolic dyssynchrony index (P = 0.006) during exercise emerged as independent determinants of exercise-induced increases in BNP (R(2) = 0.45). CONCLUSION: MR severity, volume overload, and LV filling pressure are surrogates of BNP at rest. During exercise, changes in BNP reflect the presence of dynamic changes in both LV dyssynchrony and MR severity in the absence of inducible ischaemia. [less ▲]Detailed reference viewed: 17 (2 ULg)
Effects of surgery on ischaemic mitral regurgitation: a prospective multicentre registry (SIMRAM registry).
Lancellotti, Patrizio ; ; et al
in European Journal of Echocardiography (2008), 9(1), 26-30
AIMS: Functional ischaemic mitral regurgitation (IMR) is common in patients with ischaemic left ventricular dysfunction undergoing coronary artery bypass surgery. Although the presence of IMR negatively ... [more ▼]
AIMS: Functional ischaemic mitral regurgitation (IMR) is common in patients with ischaemic left ventricular dysfunction undergoing coronary artery bypass surgery. Although the presence of IMR negatively affects prognosis, the additional benefit of valve repair is debated, particularly with mild IMR at rest. Exercise echocardiography may help identify a subset of patients at higher risk of cardiovascular events by revealing the dynamic component of IMR. METHODS: A large prospective, multicentre, non-randomized registry is designed to evaluate the effects of surgery on IMR at rest and on its dynamic component at exercise (z). SIMRAM will enrol approximately 550 patients with IMR in up to 17 centres with clinical and exercise follow-up for 1 year. Three sets of outcomes will be prospectively assessed and several hypotheses will be tested including determinants of adverse outcome and progressive left ventricular remodeling, efficacy of treatment and role of ischaemia on the dynamic consequences of IMR. Enrolment began in November 2006 and is expected to end by early 2008. [less ▲]Detailed reference viewed: 8 (2 ULg)