| 1. |
- Forsberg, Lena, 1983-
(författare)
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Cardiac Function and Aortic Valve Intervention : Echocardiographic Studies of Myocardial Recovery in Patients with Severe Aortic Valve Disease
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In patients with severe aortic valve disease, aortic valve intervention is performed when the risk for mortality or morbidity with conservative management is significantly increased. Left ventricular (LV) longitudinal motion decreases before conventional echocardiographic measures such as ejection fraction, are influenced in patients with severe aortic valve disease. This thesis is devoted to the assessment of cardiac function, including ventricular longitudinal motion, by echocardiography before and after aortic valve intervention in patients with chronic severe aortic regurgitation (AR) or severe aortic stenosis (AS).Patients with chronic AR (n=29) were studied preoperatively, and 6 months and 4 years postoperatively by echocardiography, including tissue Doppler imaging, at rest and during exercise. LV longitudinal function (atrioventricular plane displacement, AVPD, and peak systolic velocity, PSV) decreased postoperatively, and patients with low PSV continued to show reduced longitudinal function 6 months after surgery. Preoperative exercise echocardiographic variables showed a strong correlation to late LV function variables, while preoperative variables obtained at rest were not useful for prediction. Exercise echocardiography and longitudinal LV function could therefore be useful complements in the timing of aortic valve surgery for AR.Patients with chronic AR (n=29) were studied preoperatively, and 6 months and 4 years postoperatively by echocardiography, including tissue Doppler imaging, at rest and during exercise. LV longitudinal function (atrioventricular plane displacement, AVPD, and peak systolic velocity, PSV) decreased postoperatively, and patients with low PSV continued to show reduced longitudinal function 6 months after surgery. Preoperative exercise echocardiographic variables showed a strong correlation to late LV function variables, while preoperative variables obtained at rest were not useful for prediction. Exercise echocardiography and longitudinal LV function could therefore be useful complements in the timing of aortic valve surgery for AR.
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| 2. |
- Forsberg, Lena M, et al.
(författare)
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Differences in recovery of left and right ventricular function following aortic valve interventions : a longitudinal echocardiographic study in patients undergoing surgical, transapical or transfemoral aortic valve implantation
- 2013
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Ingår i: Catheterization and cardiovascular interventions. - : Wiley. - 1522-1946 .- 1522-726X. ; 82:6, s. 1004-1014
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo evaluate longitudinal left and right ventricular function (LVF and RVF) after transcatheter aortic valve implantation (TAVI) as compared to surgical aortic valve replacement (SAVR) and LVF and RVF after TAVI by the transfemoral (TF) or transapical (TA) approach.BackgroundKnowledge about differences in recovery of LVF and RVF after TAVI and SAVR is scarce.MethodsSixty patients (age 81 ± 7 years, logistic EuroSCORE 16 ± 10%), undergoing TAVI (TF: n = 35 and TA: n = 25), were examined by echocardiography including atrioventricular plane displacement (AVPD) and peak systolic velocities (PSV) by tissue Doppler at basal RV free wall, LV lateral wall and septum preprocedurally, 7 weeks and 6 months postprocedurally. Twenty-seven SAVR patients were matched to 27 TAVI patients by age, gender and LVF.ResultsEarly postintervention, TAVI patients had improved longitudinal LVF. However, when analyzed separately, only TF, but not TA patients, had improved LV lateral and septal AVPD and PSV (all P ≤ 0.01). All TAVI patients, as well as the TF and TA group had unchanged longitudinal LVF between the early and late follow-ups (all P > 0.05). The SAVR group had higher septal LVF than the matched TAVI group preprocedurally, while postoperatively this difference was diminished. Longitudinal RVF was better in the TF group than in the TA group pre- and postprocedurally. Although the SAVR group had superior longitudinal RVF preoperatively, this was inferior to TAVI postoperatively.Conclusions Postprocedural longitudinal LVF and RVF in patients undergoing TF-TAVI, TA-TAVI, or SAVR differ considerably. Preservation of longitudinal RVF after TAVI might influence the selection of aortic valve intervention in the future.
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| 3. |
- Forsberg, Lena M, et al.
(författare)
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Left and right ventricular function in aortic stenosis patients 8 weeks post-transcatheter aortic valve implantation or surgical aortic valve replacement
- 2011
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Ingår i: European Journal of Echocardiography. - : Oxford University Press (OUP). - 1525-2167 .- 1532-2114. ; 12:8, s. 603-611
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Tidskriftsartikel (refereegranskat)abstract
- Aims Knowledge of longitudinal left and right ventricular (LV and RV) function after transcatheter aortic valve implantation (TAVI) is scarce. We hypothesized that the longitudinal systolic biventricular function in aortic stenosis (AS) patients is affected differently by TAVI and surgical aortic valve replacement (SAVR). less thanbrgreater than less thanbrgreater thanMethods and results Thirty-three AS patients (all-TAVI group, age 81 +/- 9 years, 18 female), with EuroSCORE 18 +/- 9%, were accepted for TAVI. Seventeen of these patients were matched (by gender, age, and LV function) to 17 patients undergoing SAVR. Conventional echocardiographic parameters, systolic atrioventricular plane displacement (AVPD) at standard sites and peak systolic velocity (PSV) by pulsed tissue Doppler at basal RV free wall, LV lateral wall, and septum were studied before and 8 weeks after the procedure. Procedural success was 100%, and 30-day mortality 9%. In all TAVI patients, AVPD(lateral), PSV(lateral), AVPD(septal), and PSV(septal) increased (P andlt; 0.001, 0.003, 0.006 and 0.002). When studying the matched patients postoperatively, both the SAVR and TAVI patients had increased PSV(lateral) and AVPD(lateral) (SAVR: P = 0.03 and P = 0.04, TAVI: P = 0.04 and P = 0.01). The PSV(RV) increased in the all-TAVI group (P = 0.007), while the AVPD(RV) was unchanged. SAVR patients had decreased AVPD(RV) (P = 0.001) and PSV(RV) (P = 0.004), while the matched TAVI patients had unchanged RV function parameters. less thanbrgreater than less thanbrgreater thanConclusion An improvement in regional longitudinal LV function in the septal and lateral wall could be seen after TAVI. Among the matched patients, both the TAVI and SAVR patients seemed to improve LV function in the lateral wall. RV systolic function increased in TAVI patients, but was impaired in the matched SAVR group at the 8-week follow-up.
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| 4. |
- Hedman, Kristofer, et al.
(författare)
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Decreased aerobic capacity 4 years after aortic valve replacement in male patients operated upon for chronic aortic regurgitation
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 32:3, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- Exercise testing is underutilized in patients with valve disease. We have previously found a low physical work capacity in patients with aortic regurgitation 6 months after aortic valve replacement (AVR). The aim of this study was to evaluate aerobic capacity in patients 4 years after AVR, to study how their peak oxygen uptake (peakVO2) had changed postoperatively over a longer period of time. Twenty-one patients (all men, 52 +/- 13 years) who had previously undergone cardiopulmonary exercise testing (CPET) pre- and 6 months postoperatively underwent maximal exercise testing 49 +/- 15 months postoperatively using an electrically braked bicycle ergometer. Breathing gases were analysed and the patients physical fitness levels categorized according to angstrom strands and Wassermans classifications. Mean peakVO2 was 22.8 +/- 5.1 ml x kg-1 x min-1 at the 49-month follow-up, which was lower than at the 6-month follow-up (25.6 +/- 5.8 ml x kg-1 x min-1, P = 0.001). All but one patient presented with a physical fitness level below average using angstrom strands classification, while 13 patients had a low physical capacity according to Wassermans classification. A significant decrease in peakVO2 was observed from six to 49 months postoperatively, and the decrease was larger than expected from the increased age of the patients. CPET could be helpful in timing aortic valve surgery and for the evaluation of need of physical activity as part of a rehabilitation programme.
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| 5. |
- Helin Forsberg,, Lena, et al.
(författare)
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Preoperative Longitudinal Left Ventricular Function by Tissue Doppler Echocardiography at Rest and During Exercise Is Valuable in Timing of Aortic Valve Surgery in Male Aortic Regurgitation Patients
- 2010
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Ingår i: Journal of the American Society of Echocardiography. - : Elsevier Science B.V. Amsterdam. - 0894-7317 .- 1097-6795. ; 23:4, s. 387-395
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this study was to evaluate if left ventricular (LV) systolic function by tissue Doppler echocardiography at rest and during exercise preoperatively could predict postoperative LV function and thereby be useful in the timing of aortic valve surgery in patients with severe aortic regurgitation. Methods: In 29 patients (median age, 59 years; interquartile range, 39-64 years), echocardiography, tissue Doppler echocardiography, and radionuclide ventriculography were performed preoperatively and postoperatively at rest and during supine bicycle exercise. Results: Preoperative ejection fraction (EF) was 62%. Patients formed two groups, with basal LV peak systolic velocity (PSV) 5.9 cm/s preoperatively as the cutoff value between low and high PSV. Preoperatively, patients with low PSV had lower PSV during exercise (Pandlt;.005), EF during exercise (Pandlt;.05), and atrioventricular plane displacement (AVPD) at rest (Pandlt;.005) and during exercise (P andlt;.05) than those with high PSV. Postoperatively, patients with low PSV had smaller AVPD at rest (P andlt;.05), AVPD during exercise (Pandlt;.01), and PSV during exercise (Pandlt;.01). Conclusion: In patients with chronic aortic regurgitation with EFs and LV dimensions not fulfilling criteria for surgery according to guidelines, preoperative PSV and AVPD at rest and during exercise detected postoperative LV dysfunction.
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| 6. |
- Nilsson, Jessica, et al.
(författare)
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Salicylamide and salicylglycine oxidovanadium complexes with insulin-mimetic properties.
- 2011
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Ingår i: Journal of Inorganic Biochemistry. - : Elsevier BV. - 1873-3344 .- 0162-0134. ; 105, s. 1795-1800
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Tidskriftsartikel (refereegranskat)abstract
- Reaction of N-(2-hydroxybenzyl)-N-(2-picolyl) glycine (H(2)papy) with VOSO(4) in water gives the oxidovanadium(V) oxido-bridged dimer [{(papy)(VO)}(2) μ-O)] (1). Similarly, reaction of N-(2-hydroxybenzyl) glycine (H(2)glysal) with VOSO(4) gives [(glysal)VO(H(2)O)] (2) and reaction of salicylamide (Hsalam) with VOSO(4) in methanol gives [(salam)(2)VO] (3). The crystal structure of the oxido-bridged complex 1 is reported. The insulin-mimetic activity of all three complexes was evaluated with respect to their ability to phosphorylate protein kinase B (PKB). The speciations of complexes 1 and 2 were studied over the pH range 2-10. Complex 1 shows greater stability over the whole pH range but only 2 and 3 exhibit an insulin-mimetic effect.
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| 7. |
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| 8. |
- Székely, Éva, et al.
(författare)
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Synthesizing expressive speech from amateur audiobook recordings
- 2012
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Ingår i: Spoken Language Technology Workshop (SLT). ; , s. 297-302
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Konferensbidrag (refereegranskat)abstract
- Freely available audiobooks are a rich resource of expressive speech recordings that can be used for the purposes of speech synthesis. Natural sounding, expressive synthetic voices have previously been built from audiobooks that contained large amounts of highly expressive speech recorded from a profes- sionally trained speaker. The majority of freely available au- diobooks, however, are read by amateur speakers, are shorter and contain less expressive (less emphatic, less emotional, etc.) speech both in terms of quality and quantity. Synthesiz- ing expressive speech from a typical online audiobook there- fore poses many challenges. In this work we address these challenges by applying a method consisting of minimally su- pervised techniques to align the text with the recorded speech, select groups of expressive speech segments and build expres- sive voices for hidden Markov-model based synthesis using speaker adaptation. Subjective listening tests have shown that the expressive synthetic speech generated with this method is often able to produce utterances suited to an emotional mes- sage. We used a restricted amount of speech data in our exper- iment, in order to show that the method is generally applicable to most typical audiobooks widely available online.
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| 9. |
- Wickham, Abeni M., et al.
(författare)
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Polycaprolactone–thiophene-conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells
- 2014
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Ingår i: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : John Wiley & Sons. - 1552-4973 .- 1552-4981. ; 102:7, s. 1553-1561
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Tidskriftsartikel (refereegranskat)abstract
- The myocardium is unable to regenerate itself after infarct, resulting in scarring and thinning of the heart wall. Our objective was to develop a patch to buttress and bypass the scarred area, while allowing regeneration by incorporated cardiac stem/progenitor cells (CPCs). Polycaprolactone (PCL) was fabricated as both sheets by solvent casting, and fibrous meshes by electrospinning, as potential patches, to determine the role of topology in proliferation and phenotypic changes to the CPCs. Thiophene-conjugated carbon nanotubes (T-CNTs) were incorporated to enhance the mechanical strength. We showed that freshly isolated CPCs from murine hearts neither attached nor spread on the PCL sheets, both with and without T-CNT. As electrospun meshes, however, both PCL and PCL/T-CNT supported CPC adhesion, proliferation, and differentiation. The incorporation of T-CNT into PCL resulted in a significant increase in mechanical strength but no morphological changes to the meshes. In turn, proliferation, but not differentiation, of CPCs into cardiomyocytes was enhanced in T-CNT containing meshes. We have shown that changing the topology of PCL, a known hydrophobic material, dramatically altered its properties, in this case, allowing CPCs to survive and differentiate. With further development, PCL/T-CNT meshes or similar patches may become a viable strategy to aid restoration of the postmyocardial infarction myocardium.
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| 10. |
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