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Dive into the research topics where Lars Wallby is active.

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Featured researches published by Lars Wallby.


Heart | 2002

T lymphocyte infiltration in non-rheumatic aortic stenosis : a comparative descriptive study between tricuspid and bicuspid aortic valves.

Lars Wallby; Birgitta Janerot-Sjöberg; T Steffensen; Mats Broqvist

Background: The two most common causes of aortic stenosis are primary “degenerative” calcification of tricuspid aortic valves and secondary calcification of congenital bicuspid valves. T lymphocyte infiltration occurs in stenotic tricuspid aortic valves, indicating an inflammatory component, but it has not been shown whether it also occurs in stenotic bicuspid valves. Objective: To compare non-rheumatic tricuspid and bicuspid stenotic aortic valves for the presence and distribution of T lymphocytes. Setting: University hospital. Patients and design: Valve specimens were obtained from 29 patients (15 women, 14 men, mean age 69 years (range 52–81 years)), referred to the hospital for aortic valve replacement because of symptomatic aortic valve stenosis. There were 17 tricuspid valves (from 10 women and seven men, mean age 71 years) and 12 bicuspid valves (from five women and seven men, mean age 67 years). To identify mononuclear inflammatory cells, sections were stained with antibodies for CD3 (pan-T cell antigen, Dako 1:400) and then graded histologically according to the degree of T cell infiltrate. Results: T lymphocyte infiltration was present in both tricuspid and bicuspid stenotic aortic valves, without any significant differences in extent or localisation. Conclusions: Stenotic bicuspid aortic valves show the same degree of T lymphocyte infiltration as degenerative tricuspid aortic valves. Inflammation needs to be considered in the pathogenesis of acquired aortic stenosis, irrespective of the primary valve anomaly.


Catheterization and Cardiovascular Interventions | 2011

Echo-guided presentation of the aortic valve minimises contrast exposure in transcatheter valve recipients

Jacek Baranowski; Henrik Casimir Ahn; Wolfgang Freter; Niels-Erik Nielsen; Eva Nylander; Birgitta Janerot-Sjöberg; Michael Sandborg; Lars Wallby

Objectives: We have developed a method using transthoracic echocardiography in establishing optimal visualization of the aortic root, to reduce the amount of contrast medium used in each patient. Background: During transcatheter aortic valve implantation, it is necessary to obtain an optimal fluoroscopic projection for deployment of the valve showing the aortic ostium with the three cusps aligned in the beam direction. This may require repeat aortic root angiograms at this stage of the procedure with a high amount of contrast medium with a risk of detrimental influence on renal function. Methods: We studied the conventional way and an echo guided way to optimize visualisation of the aortic root. Echocardiography was used initially allowing easier alignment of the image intensifier with the transducers direction. Results: Contrast volumes, radiation/fluoroscopy exposure times, and postoperative creatinine levels were significantly less in patients having the echo‐guided orientation of the optimal fluoroscopic angles compared with patients treated with the conventional approach. Conclusion: We present a user‐friendly echo‐guided method to facilitate fluoroscopy adjustment during transcatheter aortic valve implantation. In our series, the amounts of contrast medium and radiation have been significantly reduced, with a concomitant reduction in detrimental effects on renal function in the early postoperative phase.


Cardiology Research and Practice | 2013

Inflammatory Characteristics of Stenotic Aortic Valves: A Comparison between Rheumatic and Nonrheumatic Aortic Stenosis

Lars Wallby; Thora Steffensen; Lena Jonasson; Mats Broqvist

Background. Although our comprehension of nonrheumatic aortic stenosis (NRAS) has increased substantially during the last decade, less is known about the histopathology of rheumatic aortic stenosis (RAS). The aim of this study was to investigate rheumatic aortic stenosis by means of analyses previously used in nonrheumatic stenosis. Material and Methods. Valve specimens were obtained from 39 patients referred to hospital due to significant aortic stenosis. According to established macroscopic criteria the valves were divided into two groups consisting of 29 NRAS and 10 RAS valves. Mononuclear inflammatory cells and apolipoproteins were investigated using immunohistochemical analyses. Results. The localisation of calcification differed in tricuspid nonrheumatic valves when compared to bicuspid nonrheumatic and rheumatic valves. The RAS valves revealed a lower degree of T lymphocyte infiltration compared with the NRAS valves. Infiltration of macrophages was seen in all valves and there were no differences regarding deposition of apolipoprotein. Conclusion. Rheumatic and nonrheumatic aortic stenotic valves show a similar and significant chronic inflammation. The similarities regarding the localisation of calcification indicate that the valve anomaly/morphology can influence the pathogenesis of aortic stenosis. Finally, our findings highlight the question of a postinflammatory valvular disease of other causes than rheumatic fever.


Echo research and practice | 2015

Knowledge based 3D reconstruction of the right ventricle: comparison with cardiac magnetic resonance in adults with congenital heart disease

Aleksandra Trzebiatowska-Krzynska; Mieke M. P. Driessen; Gertjan T. Sieswerda; Lars Wallby; Eva Swahn; Folkert J. Meijboom

Aim Assessment of right ventricular (RV) function is a challenge, especially in patients with congenital heart disease (CHD). The aim of the present study is to assess whether knowledge-based RV reconstruction, used in the everyday practice of an echo-lab for adult CHD in a tertiary referral center, is accurate when compared to cardiac magnetic resonance (CMR) examination. Subjects and methods Adult patients who would undergo CMR for assessment of the RV were asked to undergo an echo of the heart for further knowledge-based reconstruction (KBR). Echocardiographic images were acquired in standard views using a predefined imaging protocol. RV volumes and ejection fraction (EF) calculated using knowledge-based technology were compared with the CMR data of the same patient. Results Nineteen consecutive patients with congenital right heart disease were studied. Median age of the patients was 28 years (range 46 years). Reconstruction was possible in 16 out of 19 patients (85%). RV volumes assessed with this new method were smaller than with CMR. Indexed end diastolic volumes were 114±17 ml vs 121±19 ml, P<0.05 and EFs were 45±8% vs 47±9%, P<0.05 respectively. The correlation between the methods was good with an intraclass correlation of 0.84 for EDV and 0.89 for EF, P value <0.001 in both cases. Conclusion KBR enables reliable measurement of RVs in patients with CHDs and can be used in clinical practice for analysis of volumes and EFs.


PLOS ONE | 2018

Afterload dependence of right ventricular myocardial deformation: A comparison between tetralogy of Fallot and atrially corrected transposition of the great arteries in adult patients

Aleksandra Trzebiatowska-Krzynska; Eva Swahn; Lars Wallby; Niels Erik Nielsen; Carl-Johan Carlhäll; Lars Brudin; Jan Engvall

Background Prior studies suggested that myocardial deformation is superior to conventional measures for assessing ventricular function. This study aimed to evaluate right ventricular (RV) myocardial deformation in response to increased afterload. Patients with the RV in the systemic position were compared with patients with the RV in the sub-pulmonic position with normal or only slightly elevated systolic right ventricular pressure. Correlations between global longitudinal strain (GLS), radial strain, atrioventricular plane displacement (AVPD), and exercise capacity were evaluated. Methods 44 patients with congenital heart defect were enrolled in the study. The control group consisted of seven healthy volunteers. All patients underwent cardiovascular magnetic resonance (CMR) and cardiopulmonary exercise testing. We assessed biventricular myocardial function using CMR based feature tracking and compared the results to anatomic volumes. Results Strain analysis and displacement measurements were feasible in all participants. RVGLS and RVAVPD were reduced in both study groups compared to the control group (p<0.001). Left ventricular (LV) radial strain was significantly lower in patients with a systemic RV than in those with a subpulmonic RV and lower than in controls (p<0.001). Both LVAVPD and RVAVPD were significantly depressed in patients compared to controls (p<0.05). RVAVPD was more depressed in patients with a high systolic RV pressure than in those with normal RV pressure (p<0.001). RVAVPD did not correlate with exercise capacity in either study group. Exercise capacity in both patient groups was depressed to levels reported in previous studies, and did not correlate with RVGLS. Conclusions Both study groups had abnormal myocardial deformation and increased RV volumes. RVGLS in patients was lower than in controls, confirming the effect of increased afterload on myocardial performance.


Archive | 2013

Massive Air Embolism During MitraClip Insertion

Niels Erik Nielsen; Jacek Baranowski; Eva Nylander; Lars Wallby

This case describes massive air embolism occurring a MitraClip procedure. This most likely occurred when the guide catheter was against the left atrial wall, resulting in external air entrainment. There was air embolism to the right coronary artery causing acute myocardial ischemia and ventricular fibrillation. The patient was successfully rescued and recovered. She underwent a successful MitraClip procedure subsequently.


Archive | 2013

MitraClip in a Patient with Dextrocardia and Scoliosis Complicated by Delayed Clip Detachment

Niels Erik Nielsen; Jacek Baranowski; Eva Nylander; Lars Wallby

A patient with dextrocardia, scoliosis, restrictive lung disease, severe degenerative mitral regurgitation (MR), and with NYHA Class III heart failure was referred for the MitraClip after unsuccessful surgery. The procedure was complicated by difficult visualization of cardiac anatomy requiring adjunctive imaging with intracardiac echo. Although there was successful leaflet grasp with reduction of MR, the patient deteriorated a few days later with complete clip detachment and return of severe MR.


Cardiovascular Pathology | 2007

Role of inflammation in nonrheumatic, regurgitant heart valve disease. A comparative, descriptive study regarding apolipoproteins and inflammatory cells in nonrheumatic heart valve disease

Lars Wallby; Thora Steffensen; Mats Broqvist


Thoraxmöte 16-18 oktober 2013, Linköping | 2013

Transcatheter aortic valve implantation without prior balloon dilatation - a non-randomized single centre experience

Jacek Baranowski; Lars-Göran Dahlin; Niels-Erik Nielsen; Eva Nylander; Lars Wallby; Henrik Casimir Ahn


Journal of the American College of Cardiology | 2013

TCT-716 Transcatheter Aortic Valve Implantation without prior balloon dilatation - a non-randomized single centre experience

Niels Erik Nielsen; Henrik Casimir Ahn; Jacek Baranowski; Lars-Göran Dahlin; Eva Nylander; Lars Wallby

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Eva Swahn

Linköping University

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