37 research outputs found

    Impaired cardiac reserve in asymptomatic patients with moderate pulmonary restenosis late after relief of severe pulmonary stenosis: Evidence for diastolic dysfunction

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    BACKGROUND: Patients with moderate pulmonary valve restenosis late after relief of severe pulmonary stenosis (PS) may show decreased exercise tolerance. To elucidate the mechanism of decreased exercise tolerance, we evaluated cardiac response to physical and pharmacological stress in these patients and compared results with those of patients with native moderate PS. METHODS: Twenty asymptomatic patients with moderate PS were divided into 2 groups: Group I (late after relief of severe PS, n=9), and Group II (no previous intervention, n=11). All patients underwent an exercise test, dobutamine stress (DS) MRI, and delayed contrast enhanced MRI. The response to physical and pharmacological stress was compared between both groups. RESULTS: Group I showed impaired exercise capacity compared to Group II (VO(2)max=72.8%±3.5% vs. 102.5%±16.3%, p<0.001). During DS-MRI, RV-SV increased in Group II, but not in Group I (+13±8ml, -5±8ml, p<0.001). RV end-diastolic volume decreased significantly in Group I patients (p=0.006) while it did not significantly change in Group II patients. The amount of RV-SV increase (∆ RV-SV) correlated negatively with the period of moderate PS existence and the current PG in Group I (r=-0.82, p=0.007, and r=-0.68, p=0.04, respectively) but not in Group II (r=0.45, p=0.1, and r=0.40, p=0.2, respectively). Furthermore, ∆ RV-SV correlated negatively with the PG before valvuloplasty (r=-0.76, p=0.02). CONCLUSION: Impaired exercise capacity in patients with moderate pulmonary restenosis after relief of severe PS is probably caused by inability to increase RV-SV. Disturbed RV filling properties, worsening in time, might play a role.Cardiolog

    Exercise capacity and ventricular function in patients treated for isolated pulmonary valve stenosis or tetralogy of Fallot

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    BACKGROUND We hypothesized 1) that long-term ventricular outcome and exercise capacity would be better in patients with isolated pulmonary valve stenosis (PS) treated with balloon pulmonary valvuloplasty (BPV) than in patients operated for tetralogy of Fallot (TOF), and 2) that ventricular outcome and exercise capacity would not be different in PS patients and healthy controls. METHODS We included 21 PS patients after BPV (16.2 ± 5.2 years) and 21 patients operated for TOF (16.6 ± 5.6 years), matching them for gender, age at treatment, and age at study. Patients underwent cardiovascular magnetic resonance (CMR) imaging, exercise testing, 12-lead ECG and 24-hour Holter monitoring for assessment of right ventricular (RV) size and function, pulmonary regurgitation (PR), exercise capacity and electrocardiographic status. Healthy controls for CMR imaging and exercise testing were matched for gender and age at study. RESULTS RV volumes and PR percentage were significantly larger in TOF patients than in PS patients; biventricular ejection fraction (EF) was not different. PR was mild in most PS patients. RV end-systolic volume was significantly larger in PS patients than in healthy controls; RVEF was significantly lower. Both patient groups had similar exercise test results. Peak workload and VO(2) max. were significantly lower in PS patients than in healthy controls. CONCLUSIONS Longstanding mild PR in PS patients can lead to an enlarged RV, reduced RV function and reduced exercise capacity. Despite more PR and larger RV volumes in TOF patients, exercise capacity and biventricular function are similar in both patient groups

    Is cardiac CT a reproducible alternative for cardiac MR in adult patients with a systemic right ventricle?

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    Objective 20 % of patients with a systemic RV are pacemaker dependent, and unsuitable to undergo cardiac magnetic resonance (CMR). Multidetector row computed tomography (MDCT) could provide a reproducible alternative to CMR in these patients. The aim of this study was to compare variability of MDCT with CMR. Methods Thirty-five patients with systemic RV underwent either MDCT (n = 15) or CMR (n = 20). Systemic RV volumes and ejection fraction were obtained, and intra- and interobserver variability for both modalities were assessed and compared. Results We found the intra- and interobserver variability of volumes and function measurements of the systemic RV obtained with MDCT to be higher compared with those obtained with CMR. However, these differences in variability were not significant, the only exception being the interobserver variability of systemic RV stroke volume. Conclusions MDCT provides a reproducible alternative to CMR for volumes and function assessment in patients with a systemic R

    The coach-athlete relationship: a motivation model

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    OBJECTIVE: To evaluate differences in functional parameters and reproducibility between short axis and axial slice orientation in the quantitative evaluation of the systemic right ventricle by cardiovascular magnetic resonance. DESIGN: Cross-sectional evaluation comparing two methods (Bland-Altman). SETTING: Tertiary care outpatients. INTERVENTIONS: Quantitative cardiovascular magnetic resonance evaluation using short axis or axial slice orientation. MAIN OUTCOME MEASURES: Intraobserver variance, interobserver variance and systematic differences in systemic right ventricular volumes, ejection fraction, and mass between both methods. PATIENTS: Twenty-two patients (mean age 33 +/- 7 years) with systemic right ventricle (three with congenitally corrected transposition of the great arteries and 19 with atrially switched transposition of the great arteries). RESULTS: Compared with short axis slices, analysis of axial slices resulted in higher end systolic volume (6.6%, P < .01), while mass (-10.8%, P < .01) and ejection fraction (-8.9%, P < .01) turned out lower. Intraobserver and interobserver reproducibility were similar for both methods when measuring end-diastolic and end-systolic volumes. However, ejection fraction and stroke volume were measured more consistently in axial orientation, while ventricular mass was measured more consistently in short axis orientation. CONCLUSION: There are significant differences in volume, mass, and function between measurements in axial and short axis orientation. Ejection fraction and stroke volume, which have a high clinical relevance, were measured more consistently in axial slice orientation. Consequently, we recommend using axial slice orientation in patients with a systemic right ventricle

    Ventricular function and cardiac reserve in contemporary Fontan patients

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    Item does not contain fulltextBACKGROUND/OBJECTIVE: Total cavopulmonary connection (TCPC) has been the preferred treatment for patients with univentricular hearts. Current TCPC-techniques are the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). We aimed to determine ventricular function during rest and stress, and to compare results for both techniques and for left (LV) versus right ventricular (RV) dominance. METHODS: 99 patients, aged 12.5 +/- 4.0 years underwent echocardiography and magnetic resonance imaging (MRI), and 69 patients underwent stress MRI. RESULTS: Echocardiography showed impaired systolic and diastolic function. MRI parameters were comparable between ILT and ECC at rest. During dobutamine there was a decrease in end-diastolic volume (EDVi) (91 +/- 21 vs. 80 +/- 20 ml/m(2) p<0.001). Ejection fraction (EF) and cardiac index (CI) during dobutamine were lower for ILT patients (59 +/- 11 (ILT) vs. 64 +/- 7% (ECC), p=0.027 and 4.2 +/- 1.0 (ILT) vs. 4.9 +/- 1.0L/min/m(2) (ECC), p=0.006), whereas other parameters were comparable. TEI-index was higher in ILT-patients (0.72 +/- 0.27 (ILT) vs. 0.56 +/- 0.22 (ECC), p=0.002). Diastolic function was frequently impaired in patients with a dominant RV (67% (RV) vs. 39% (LV), p=0.011). Patients with dominant LV's had smaller end-systolic volume (ESVi) (40 +/- 13 (LV) vs. 47 +/- 16 (RV) ml/m(2), p=0.030) and higher EF (55 +/- 8 (LV) vs. 49 +/- 9 ml/m(2) (RV), p=0.001) and contractility (2.3 +/- 0.8 (LV) vs. 1.9 +/- 0.7 mmHg/ml/m(2) (RV), p=0.050) during rest and higher EF during dobutamine (63 +/- 8 (LV) vs. 58 +/- 10 ml/m(2) (RV), p=0.043). CONCLUSION: Ventricular function is relatively well preserved in modern-day Fontan patients. With dobutamine stress there is a decrease in EDVi. ECC patients have higher CI and EF during stress. Patients with a dominant RV have lower systolic, including impaired contractility, and diastolic function

    Analysis of the gene expression profile of Schistosoma mansoni cercariae using the expressed sequence tag approach

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    ESTs constitute rapid and informative tools with which to study gene-expression profiles of the diverse stages of the schistosome life cycle. Following a comprehensive EST study of adult worms, analysis has now targeted the cercaria, the parasite larval form responsible for infection of the vertebrate host. Two Schistosoma mansoni cercarial cDNA libraries were examined and partial sequence obtained from 957 randomly selected clones. On the basis of database searches, 551 (57.6%) ESTs generated had no homologs in the public databases whilst 308 (32.2%) were putatively identified, totaling 859 informative ESTs. The remaining 98 (10.2%) were uninformative ESTs (ribosomal RNA and non-coding mitochondrial sequences). By clustering analysis we have identified 453 different genes. The most common sequences in both libraries represented Sm8 calcium binding protein (8% of ESTs), fructose-1,6-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, cytochrome oxidase subunit 1, ATP guanidine kinase and triose phosphate isomerase. One hundred and nineteen identified genes were sorted into 11 functional categories, with genes associated with energy metabolism being the most abundant (13%) and diverse. The diversity and abundance of genes associated with the transcription/translation machinery and with regulatory/signaling functions were also marked. A paramyosin transcript was identified, indicating that this gene is not exclusively expressed in adult worms and sporocysts (as had been suggested previously). The possible physiological relevance to cercariae of the presence of transcripts with homology to calcium binding proteins of the EF-hand superfamily, Gq-coupled rhodopsin photoreceptor, rod phosphodiesterase 8 subunit and peripheral-type benzodiazepine receptor is discussed

    Valvulogenesis of a living, innervated pulmonary root induced by an acellular scaffold

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    Heart valve disease is a major cause of mortality and morbidity worldwide with no effective medical therapy and no ideal valve substitute emulating the extremely sophisticated functions of a living heart valve. These functions influence survival and quality of life. This has stimulated extensive attempts at tissue engineering "living" heart valves. These attempts utilised combinations of allogeneic/ autologous cells and biological scaffolds with practical, regulatory, and ethical issues. In situ regeneration depends on scaffolds that attract, house and instruct cells and promote connective tissue formation. We describe a surgical, tissue-engineered, anatomically precise, novel off-the-shelf, acellular, synthetic scaffold inducing a rapid process of morphogenesis involving relevant cell types, extracellular matrix, regulatory elements including nerves and humoral components. This process relies on specific material characteristics, design and "morphodynamism"
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