519 research outputs found

    Curved track sprint characteristics in elementary school children

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    The management strategies of patients who underwent Mustard repair for transposition (of the great arteries were changed in the 1970s: infants became eligible for direct surgical repair, so Blalock-Hanlon atrioseptostomy could be avoided, and cold cardioplegia was introduced for myocardial preservation. Data are lacking, however, regarding whether these changes have had positive effects on the long-term outcome. We therefore conducted a follow-up study on all 91 patients who underwent a Mustard repair for transposition of the great arteries in our institution between 1973 and 1980 to assess the incidence and clinical importance of sequelae as well as health-related quality of life for these patients. Patients who were alive and could be traced through local registrar's offices received an invitation to participate in the follow-up study, which consisted of an interview, physical examination, echocardiography, exercise testing, and standard 12-lead and 24-hour electrocardiography. Patients operated on in the first 4 years had a significantly higher mortality rate and higher incidence of sinus node dysfunction than did patients operated on in the subsequent 4 years (25% vs 2% and 41% vs 3%, respectively). In contrast, the incidence of baffle obstruction necessitating reoperation was significantly higher in the second group. There were no significant differences in echocardiographic findings and exercise capacity between patients operated on in the first 4 years and in the subsequent 4 years. None of the patients had right ventricular failure; a mild degree of baffle leakage or obstruction was seen in 22% of the patients, and the mean exercise capacity was decreased to 84% +/- 16% of normal. The changes introduced between 1973 and 1980 have resulted in a considerable reduction of mortality and incidence of sinus node dysfunction but have also resulted in a more frequent need for reoperatio

    Systemic peptide-mediated oligonucleotide therapy improves long-term survival in spinal muscular atrophy.

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    The development of antisense oligonucleotide therapy is an important advance in the identification of corrective therapy for neuromuscular diseases, such as spinal muscular atrophy (SMA). Because of difficulties of delivering single-stranded oligonucleotides to the CNS, current approaches have been restricted to using invasive intrathecal single-stranded oligonucleotide delivery. Here, we report an advanced peptide-oligonucleotide, Pip6a-morpholino phosphorodiamidate oligomer (PMO), which demonstrates potent efficacy in both the CNS and peripheral tissues in severe SMA mice following systemic administration. SMA results from reduced levels of the ubiquitously expressed survival motor neuron (SMN) protein because of loss-of-function mutations in the SMN1 gene. Therapeutic splice-switching oligonucleotides (SSOs) modulate exon 7 splicing of the nearly identical SMN2 gene to generate functional SMN protein. Pip6a-PMO yields SMN expression at high efficiency in peripheral and CNS tissues, resulting in profound phenotypic correction at doses an order-of-magnitude lower than required by standard naked SSOs. Survival is dramatically extended from 12 d to a mean of 456 d, with improvement in neuromuscular junction morphology, down-regulation of transcripts related to programmed cell death in the spinal cord, and normalization of circulating insulin-like growth factor 1. The potent systemic efficacy of Pip6a-PMO, targeting both peripheral as well as CNS tissues, demonstrates the high clinical potential of peptide-PMO therapy for SMA

    Is there a role for CT coronary angiography in patients with symptomatic angina? Effect of coronary calcium score on identification of stenosis

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    Present guidelines discourage the use of CT coronary angiography (CTCA) in symptomatic angina patients. We examined the relation between coronary calcium score (CS) and the performance of CTCA in patients with stable and unstable angina in order to understand under which conditions CTCA might be a gate-keeper to conventional coronary angiography (CCA) in such patients. We included 360 patients between 50 and 70 years old with stable and unstable angina who were clinically referred for CCA irrespective of CS. Patients received CS and CCTA on 64-slice scanners in a multicenter cross-sectional trial. The institutional review board approved the study. Diagnostic performance of CTCA to detect or rule out significant coronary artery disease was calculated on a per patient level in pre-defined CS categories. The prevalence of significant coronary artery disease strongly increased with CS. Negative CTCA were associated with a negative likelihood ratio of <0.1 independent of CS. Positive CTCA was associated with a high positive likelihood ratio of 9.4 if CS was <10. However, for higher CS the positive likelihood ratio never exceeded 3.0 and for CS >400 it decreased to 1.3. In the 62 (17%) patients with CS <10, CTCA reliably identified the 42 (68%) of these patients without significant CAD, at no false negative CTCA scans. In symptomatic angina patients, a negative CTCA reliably excludes significant CAD but the additional value of CTCA decreases sharply with CS >10 and especially with CS >400. In patients with CS <10, CTCA provides excellent diagnostic performance

    Computed tomography segmental calcium score (SCS) to predict stenosis severity of calcified coronary lesions

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    To estimate the probability of a parts per thousand yen50 % coronary stenoses based on computed tomography (CT) segmental calcium score (SCS) and clinical factors. The Institutional Review Board approved the study. A training sample of 201 patients underwent CT calcium scoring and conventional coronary angiography (CCA). All patients consented to undergo CT before CCA after being informed of the additional radiation dose. SCS and calcification morphology were assessed in individual coronary segments. We explored the predictive value of patient&apos;s symptoms, clinical history, SCS and calcification morphology. We developed a prediction model in the training sample based on these variables then tested it in an independent test sample. The odds ratio (OR) for a parts per thousand yen50 % coronary stenosis was 1.8-fold greater (p = 0.006) in patients with typical chest pain, twofold (p = 0.014) greater in patients with acute coronary syndromes, twofold greater (p &lt; 0.001) in patients with prior myocardial infarction. Spotty calcifications had an OR for a parts per thousand yen50 % stenosis 2.3-fold (p &lt; 0.001) greater than the absence of calcifications, wide calcifications 2.7-fold (p &lt; 0.001) greater, diffuse calcifications 4.6-fold (p &lt; 0.001) greater. In middle segments, each unit of SCS had an OR 1.2-fold (p &lt; 0.001) greater than in distal segments; in proximal segments the OR was 1.1-fold greater (p = 0.021). The ROC curve area of the prediction model was 0.795 (0.95 confidence interval 0.602-0.843). Validation in a test sample of 201 independent patients showed consistent diagnostic performance. In conjunction with calcification morphology, anatomical location, patient&apos;s symptoms and clinical history, SCS can be helpful to estimate the probability of a parts per thousand yen50 % coronary stenosis

    A systematic review of the clinical effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of suspected coronary artery disease

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    <p>Abstract</p> <p>Background</p> <p>This systematic review summarized recent evidence pertaining to the clinical effectiveness of 64-slice or higher computed tomography angiography (CTA) in patients with suspected coronary artery disease (CAD). If CTA proves to be a successful diagnostic performance measure, it could prevent the use of invasive diagnostic procedures in some patients. This would provide multiple health and cost benefits, particularly for under resourced areas where invasive coronary angiography is not always available.</p> <p>Methods</p> <p>A systematic method of literature searching and selection was employed with searches limited to December 2006 to March 2009. Included studies were quality assessed using National Health and Medical Research Council (NHMRC) diagnostic levels of evidence and a modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Individual and pooled diagnostic performance measures were calculated using standard meta-analytic techniques at the patient, vessel and segment level. A positive result was defined as greater than or equal to 50% stenosis.</p> <p>Results</p> <p>Twenty-eight studies were included in the systematic review examining 3,674 patients. The primary meta-analysis at the patient-level indicated a sensitivity of 98.2% and specificity of 81.6%. The median (range) positive predictive value (PPV) was 90.5% (76%-100%) and negative predictive value (NPV) 99.0% (83%-100%). In all vessels, the pooled sensitivity was 94.9%, specificity 89.5%, and median (range) PPV 75.0% (53%-95%) and NPV 99.0% (93%-100%). At the individual artery level, overall diagnostic accuracy appeared to be slightly higher in the left main coronary artery and slightly lower in the left anterior descending and circumflex artery. In all segments, the sensitivity was 91.3%, specificity 94.0% and median (range) PPV 69.0% (44%-86%) and NPV 99.0% (98%-100%).</p> <p>Conclusions</p> <p>The high sensitivity indicates that CTA can effectively identify the majority of patients with significant coronary artery stenosis. The high NPV at the patient, vessel and segment level establishes CTA as an effective non-invasive alternative to invasive coronary angiography (ICA) for the exclusion of stenosis.</p

    Computed tomography segmental calcium score (SCS) to predict stenosis severity of calcified coronary lesions

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    To estimate the probability of ≥50 % coronary stenoses based on computed tomography (CT) segmental calcium score (SCS) and clinical factors. The Institutional Review Board approved the study. A training sample of 201 patients underwent CT calcium scoring and conventional coronary angiography (CCA). All patients consented to undergo CT before CCA after being informed of the additional radiation dose. SCS and calcification morphology were assessed in individual coronary segments. We explored the predictive value of patient’s symptoms, clinical history, SCS and calcification morphology. We developed a prediction model in the training sample based on these variables then tested it in an independent test sample. The odds ratio (OR) for ≥50 % coronary stenosis was 1.8-fold greater (p = 0.006) in patients with typical chest pain, twofold (p = 0.014) greater in patients with acute coronary syndromes, twofold greater (p < 0.001) in patients with prior myocardial infarction. Spotty calcifications had an OR for ≥50 % stenosis 2.3-fold (p < 0.001) greater than the absence of calcifications, wide calcifications 2.7-fold (p < 0.001) greater, diffuse calcifications 4.6-fold (p < 0.001) greater. In middle segments, each unit of SCS had an OR 1.2-fold (p < 0.001) greater than in distal segments; in proximal segments the OR was 1.1-fold greater (p = 0.021). The ROC curve area of the prediction model was 0.795 (0.95 confidence interval 0.602–0.843). Validation in a test sample of 201 independent patients showed consistent diagnostic performance. In conjunction with calcification morphology, anatomical location, patient’s symptoms and clinical history, SCS can be helpful to estimate the probability of ≥50 % coronary stenosis

    Diagnostic accuracy of multislice computed tomography coronary angiography is improved at low heart rates

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    Purpose: Assess the effect of heart rate on diagnostic accuracy for the detection of significant coronary artery stenosis using 16-row multislice computed tomography (MSCT). Material and methods: About 120 patients (105 males; 59 ± 11 years) with suspected coronary artery disease who underwent conventional coronary angiography (CA) and MSCT-CA were retrospectively enrolled for the study. Patients underwent a MSCT-CA (Sensation 16, Siemens, Germany), with the following protocol: Collimation 16 × 0.75 mm, gantry rotation time 420 ms, feed/rotation 3.0 mm, kV 120, mAs 400-500. The protocol for contrast material administration was 100 ml of Iodixanol (Visipaque 320 mg l/ml, Amersham, UK) at 4 ml/s and the delay was defined with a bolus tracking technique. In all patients the mean heart rate (HR) during the scan was used as a criteria to divide the population in two groups of 60 patients each. In one group (Low HR) the 60 patients with lower heart rates, and in the other group (High HR) the patients with higher heart rates. In the two groups diagnostic accuracy (per coronary segment) for the detection of significant stenosis (≥50% lumen reduction) was evaluated in vessels ≥2 mm of diameter using quantitative CA as reference standard. The difference in diagnostic accuracy were compared with a Chi2 test and a p < 0.05 was considered significant. Results: There was no significant difference between the two groups regarding age, gender, weight, mean intravascular attenuation, and calcium score. Overall 1310 (652 for Low HR and 658 for High HR) segments with 219 (105 for Low HR and 114 for High HR) significant lesions were available for the analysis. The average heart rate was 52 ± 4HU and 63 ± 5HU for Low HR and High HR, respectively (p < 0.001). The sensitivity and specificity were 92 and 96% for Low HR and 90 and 92% for High HR (p < 0.05). There were 22 vs. 44 false positives, and 8 vs. 12 false negatives in the Low HR and High HR, respectively. Conclusion: Increasing HR significantly deteriorates diagnostic accuracy in MSCT-CA

    Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

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    Objectives Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. Methods ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers. Results Eighty-two CT angiograms were performed on a 64-slice ( = 27) or 256-slice ( = 55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types. Conclusions Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts. Key Points Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts Bjork-Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessmen

    Follow-up of internal mammary artery stent with 64-slice CT

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    We present a case of 81-year-old woman complaining chest pain after minimal efforts who underwent multiple coronary artery bypass grafts (CABGs) during the last 15 years. A significant in-stent re-stenosis was found at ostium of left internal mammary artery (LIMA). A non-invasive CT coronary angiography (CT-CA) was performed after 6-month follow-up. CT-CA is a reliable non-invasive technique for the follow-up of stents in coronary artery bypass grafts

    The aortic root in repaired tetralogy of Fallot:Serial measurements and impact of losartan treatment

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    Background: Aortic root dilatation is common in adults with repaired tetralogy of Fallot (rTOF) and might lead to aortic dissection. However, little is known on progression of aortic dilatation and the effect of pharmaceutical treatment. This study aims to determine factors associated with aortic growth and investigate effects of losartan. Methods and results: We performed a prespecified analysis from the 1:1 randomized, double-blind REDEFINE trial. Aortic root diameters were measured at baseline and after 2.0 ± 0.3 years of follow-up using cardiovascular magnetic resonance (CMR) imaging. A total of 66 patients were included (68% men, age 40 ± 12 years, baseline aortic root 37 ± 6 mm, 32% aortic dilatation (>40 mm)). There was a trend towards slow aortic root growth (+0.6 ± 2.3 mm after two years, p = 0.06) (n = 60). LV stroke volume was the only factor associated with both a larger baseline aortic root (β: 0.09 mm/ml (95% C.I.:0.02, 0.15), p = 0.010) and with aortic growth during follow-up (β: 0.04 mm/ml (95% C.I.:0.005, 0.066), p = 0.024), after correction for age, sex, and body surface area using linear regression analysis. No treatment effect of losartan was found (p = 0.17). Conclusions: Aortic root dilatation was present in about one-third of rTOF patients. A larger LV stroke volume was associated with both a larger baseline aortic root and ongoing growth. Our findings provide no arguments for lower aortic diameter thresholds for prophylactic surgery compared to the general population
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