| 1. |
- Backman, Christer, et al.
(författare)
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Unusual arrhythmogenic myocardial disease
- 2014
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Ingår i: International Cardiovascular Forum Journal. - : Barcaray International Publishing. - 2410-2636 .- 2409-3424. ; 1:4, s. 195-196
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Bergqvist, Erik, et al.
(författare)
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An Analysis of High and Low Intercorrelations between Mathematics Self-Efficacy, Anxiety, and Achievement Variables : A Prerequisite for a Reliable Factor Analysis
- 2020
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Ingår i: Education Research International. - : Hindawi Publishing Corporation. - 2090-4002 .- 2090-4010. ; 2020
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Tidskriftsartikel (refereegranskat)abstract
- This paper draws on data from a quantitative study of upper secondary students' general mathematical self-efficacy, anxiety towards mathematics, and their relationship to achievement in mathematics. The main objective of this article is to discuss the type of information that may be lost if potential problems of validity and extreme multicollinearity in exploratory factor analysis would be solved by only removing variables without doing a profound analysis. We also describe a method that treats Likert items in the questionnaire as ordinal variables that may represent the underlying continuous variable. Our study shows, for example, that removal of problematic variables without a profound analysis leads to a loss of significant information about test anxiety. Our qualitative analysis of problematic variables also led to an unexpected finding regarding the relationship between general mathematical self-efficacy and motivational values in mathematics.
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| 3. |
- Henein, Mark, et al.
(författare)
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Left atrial strain rate estimates PCWP
- 2013
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Ingår i: International cardiovascular forum. - 2409-3424. ; :1, s. 25-30
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Raised left atrial (LA) pressure is a common pathway for many pathologies and is known for its complications. It has a direct effect on LA cavity size and potentially also its function. We hypothesized that raised LA pressure, as shown by pulmonary capillary wedge pressure (PCWP), correlates with severity of global LA deformation abnormalities during atrial systole (LASRa). DESIGN AND PATIENTS: We prospectively studied 46 consecutive patients, mean age 61 ±13 years, 17 males, of various etiologies who underwent right heart catheterization and simultaneous Doppler echocardiography using spectral, tissue Doppler and speckle tracking echocardiography techniques for assessing LA structure and function. RESULTS: PCWP correlated with direct measurements of LA structure and function: LA volume (r= 0.43, p<0.01) and LASRa (r=0.79, p<0.001). PCWP correlated also with other indirect measures of LA pressure such as E/A (r=0.65, p<0.001), E wave deceleration time (r=0.54, p<0.001), E/e’ (r=0.49, p<0.001) and LA systolic filling fraction (r=0.52, p<0.001). However, LASRa together with LA systolic filling fraction, had the highest areas under the curve (0.83 and 0.87, respectively) for identifying patients with PCWP > 15 mmHg. CONCLUSION: PCWP correlates with LA deformation rate during atrial systole and to a higher extent than conventional Doppler measures of raised LA pressures. These findings should have significant clinical implications in correctly identifying breathless patients due to raised LA pressure.
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| 4. |
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| 5. |
- Henein, Michael Y., et al.
(författare)
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Can Doppler echocardiography estimate raised pulmonary capillary wedge pressure provoked by passive leg lifting in suspected heart failure?
- 2019
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 39:2, s. 128-134
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Non-invasive estimation of left ventricular filling pressure (LVFP) during stress is important for explaining exertional symptoms in patients with heart failure (HF). The aim of this study was to evaluate ability of Doppler echocardiographic measures of elevated LVFP with passive leg lifting (PLL) in patients with suspected HF.METHODS: Twenty-nine patients with clinical signs of HF who underwent simultaneous Doppler echocardiography and right heart catheterization (RHC) at rest and during PLL were consecutively investigated. Seventeen patients had normal PCWP (≤15 mmHg) at rest and during PLL and 12 with normal PCWP at rest but >15 mmHg with PLL. Conventional echo and 2D strain were used to assess early diastolic blood flow velocity (E), LV strain rate during early diastole (LVSRe), left atrial SR during atrial contraction (LASRa) and myocardial tissue Doppler velocities to assess lateral e' and further calculate E/e' and E/LVSRe and their relationship with PCWP, at rest and during PLL.RESULTS: Resting LAVI (β = 0·45, P = 0·009) and LASRa (β = -0·51, P = 0·004) were independently related to PCWP during PLL. Also, LASRa (β = -0·77, P<0·001), E/e' (β = 0·40, P = 0·04) and E/LVSRe (β = 0·47, P = 0·021) during PLL correlated with PCWP during PLL. Multiple regression analysis identified E/LVSRe (β = 0·46, P = 0·001) and LASRa (β = -0·58, P = 0·002) during PLL as being independently associated with PCWP during PLL.CONCLUSION: Left atrial volume and myocardial contraction (LASRa) at rest both predict unstable LV filling pressures measured as raised PCWP when provoked by PLL. Furthermore, LASRa at PLL seems to have the strongest association to PCWP during PLL.
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| 6. |
- Henein, Michael Y, et al.
(författare)
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Right and left heart dysfunction predict mortality in pulmonary hypertension
- 2017
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 37:1, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- In pulmonary hypertension (PH), the right heart dysfunction is a strong predictor of adverse clinical outcome, while the role of the left heart is not fully determined. The aim of this study was to identify predictors of mortality in precapillary PH including measures of both right and left heart function. We studied 34 patients (mean age 64 ± 13, range 31-82 years, 24 females) with precapillary PH, all of whom underwent detailed Doppler echocardiographic examination of the right and left heart function using conventional and speckle-tracking echocardiography. Patients were followed up for up to 8 years (mean 4·2 ± 1·9 years). At follow-up, 16 patients survived. Left ventricular (LV) filling time (P = 0·007), pulmonary artery acceleration time (P = 0·009), right atrial pressure (RAP) (P<0·001) and tricuspid regurgitation (TR) severity (P = 0·007) were worse in the deceased group. RV global longitudinal strain (GLS) (P = 0·001), RAP (P≤0·001), LV filling time (P<0·001) and TR severity (P<0·001) were the most accurate predictors, having the largest AUC (>0·65) and carried the highest risk for mortality (P<0·001 for all). The strongest predictors of mortality in precapillary PH indirectly reflect both left and right heart dysfunction including atrial structure and function disturbances. While an interaction pattern is observed, it needs to be confirmed in a larger cohort.
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| 7. |
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| 8. |
- Lindqvist, Per, et al.
(författare)
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Echocardiography based estimation of pulmonary vascular resistance in patients with pulmonary hypertension : a simultaneous Doppler echocardiography and cardiac catheterization study
- 2011
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Ingår i: European Journal of Echocardiography. - London : Saunders. - 1525-2167 .- 1532-2114. ; 12:12, s. 961-966
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Pulmonary vascular resistance (PVR) is an important measurement for the diagnosis of patients with pulmonary hypertension (PH) but needs accurate determination of mean pulmonary artery pressure (PAMP). We aimed to test the accuracy of a Doppler-derived measurement of PVR, using the conventional invasive equation in patients with PH.Methods and results: We investigated 30 patients undergoing right heart catheterization (RHC), mean age 62 ± 13 years, 21 females, with different diseases; idiopathic pulmonary arterial hypertension (PAH) (n= 5), associated PAH (n= 16), chronic thromboembolic PH (n= 6), interstitial lung disease (n= 2), and after closure of an atrial septal defect (n= 1). Patients with impaired left ventricular systolic function (EF < 50%) or elevated pulmonary capillary wedge pressure (PCWP >15 mmHg on RHC) were excluded. We used the formula: PAMP = PASPecho × 0.61 + 2 mmHg, where PASPecho is the peak tricuspid regurgitation pressure drop + 10 or 7 mmHg. Pulmonary vascular resistance was then calculated as PAMPecho− PCWP/cardiac output. Pulmonary capillary wedge pressure was estimated at 10 mmHg in all cases. The Doppler-derived estimation of PVRecho was achievable in 90% of patients, in whom accurate calculation of PAMP was obtainable. Pulmonary vascular resistance echo individual values strongly correlated with those from RHC (r= 0.85, P< 0.001 and r= 0.87, P< 0.001 for the two estimated values for right atrial pressure, respectively). The regression equation using this formula was PVRrhc = 0.95 × PVRecho− 0.29, and the regression line was close to identity. The Bland–Altman plot showed a good agreement between PVRecho and PVRrhc values, with a mean difference of −0.66 ± 2.1 Wood unit.Conclusion: The proposed Doppler-derived formula for estimating PVR based on the conventionally used invasive equation strongly correlates with invasive gold standard measures.
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| 9. |
- Tossavainen, Erik, 1977-
(författare)
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In the hands of ohm : hemodynamic aspects in pulmonary hypertension
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Congestive heart failure (CHF) is one of the most challenging diseases in terms of health care demand and mortality, in the western world. Despite major breakthroughs in the fields of diagnosis and treatment over the three last decades, the management of CHF still remains challenging.CHF is defined as inability of the heart to supply sufficient blood flow to meet the needs of the body. This definition however, may be an oversimplification of a complex pathophysiological process since patients with overt CHF may have normal, or even supernormal cardiac output at the expense of increased filling pressures, which subsequently leads to the development of post capillary pulmonary hypertension (PH). In the presence of advanced CHF, clinical signs and symptoms are obvious at rest. However, the majority of affected individuals do not experience any discomfort at rest and may demonstrate normal findings when assessed. Small increases in systemic blood pressure and or venous return, caused by activity may result in severe elevation of filling pressures if left ventricular compliance is significantly decreased. This example highlights the need to perform cardiac investigations during stress to provoke symptoms. Increased pulmonary vascular resistance (PVR), commonly found in pre-capillary PH, is a condition that shares many symptoms with CHF, and is also associated with poor prognosis. Even though the disease is located within the lung vessels, it is highly important and challenging task differentiating pre- and post-capillary PH. Since treatment differs considerably and may be detrimental in case of misdiagnosis, additional sensitive and reliable screening methods are crucial to aid in differentiation.Methods: Out of the four studies included in this thesis, three were conducted solely at Norrland’s University Hospital, while patients in the third study were recruited and examined at Uppsala Akademiska Hospital. All included patients had idiopathic dyspnea and were admitted for right heart catheterization (RHC), which is gold standard with regards to hemodynamics. Echocardiographic examinations were performed simultaneously with RHC, except in the Uppsala study, wherein echocardiography were performed within 3 days to the RHC.Echo-Doppler derived pulmonary artery acceleration time (PAcT) is an easily assessed parameter, indicating elevated pulmonary artery systolic pressure (PASP) and pulmonary artery resistance (PVR). PAcT was tested as a screening method for identification and differentiation of pre and post- capillary PH in a cohort of 56 patients (study 1).The ability to calculate PVR non-invasively, using novel echocardiographic measurements, was made by replacing the invasive pressure and flow components that constitutes the foundation of the PVR = (mean pulmonary artery pressure – Pulmonary capillary wedge pressure (PCWP)) /cardiac output), with novel echocardiographic measurements. PVR = mPAP-Chemla – Left atrial strain rate during atrial systole (LASRa) / Cardiac Output-Echo (study 2).Invasively measured left ventricular filling pressure in response to passive leg lifting, and its ability to predict pathological increase in left ventricular filling pressures during supine bicycling, was tested in a population of 85 patients with normal left ventricular ejection fraction (LVEF) and suspicion of CHF based on NT-proBNP levels alone were investigated (Study 3).Finally, an evaluation of standard and novel Doppler echocardiographic parameters, potentially useful in identifying patients who may develop increased filling pressures during passive leg lifting (PLL), was carried out (study 4).Results:Study 1: PAcT correlated negatively with pulmonary artery systolic pressure (PASP) (r = -0.60, p < 0.001) and PVR (r = -0.57, p < 0.001). PAcT of <90 ms had a sensitivity of 84% and a specificity of 85% in identifying patients with PVR ≥ 3.0 WU. Regardless of normal or elevated left sided filling pressures, PAcT differed significantly in patients with normal, compared to those with elevated levels of, PVR (p < 0.01). A significant difference was also found on comparison of the PAcT/PASP ratio (p < 0.01), with a lower ratio among patients with PVR ≥ 3.0. WU.Study 2: We prospectively used Doppler and 2D echocardiography in 46 patients with sinus rhythm which revealed that left atrial strain rate during atrial systole (LASRa) had the highest significant positive correlation with PCWP (r2 = 0.65, P < 0.001). By adopting a linear line of best-fit, LASRa may therefore be substituted for PCWP. Subsequently, LASRa was substituted into the PVR equation. This novel echocardiographically derived PVR calculation, significantly correlated with RHC generated PVR values (r2 = 0.69, P < 0.001) and minor drift (+0.1WU) when assessed by Bland Altman analysis.Study 3: Only 22% (11/51) of patients with elevated NT-proBNP had PCWP above normal levels at rest. However, in response to PLL, 47% of patients developed elevated PCWP, and the majority of this 47% subsequently developed pathological pressure levels while performing supine cycling exercise. Thus, the likelihood of developing high LVFPs during exercise could be determined by PLL, with a sensitivity and specificity of 90%.Study 4: At rest, left atrial volume indexed to body mass index (BMI) (LAVI) and mitral deceleration time (DT) were independently related to PCWP during PLL. However, during PLL univariate regression analysis revealed LASRa (β = -0.77, P <0,001) and E/LVSRe (β = 0.47, P < 0,021) most related to PCWPPLL. Multiple regression analysis fortified LASRa and E/LVSRe as relevant independent parameters useful in the assessment of filling pressure during PLL.Conclusion: A PAcT < 90ms is strongly suggestive of increased PVR (>3.0 WU). Based on study 1, there is clear evidence suggesting that these findings apply irrespective of LVFPs. PAcT can potentially serve as a rapid screening tool for estimation of PVR, however, is not useful if the exact level of PVR is required. In this case, an established PVR calculation method is preferred, and could be performed with higher precision by inclusion of echocardiography derived LASRa as a surrogate measure of PCWP. Insufficient LV compliance results in the inability to cope with increased cardiac preload. Nt-proBNP is secreted when the myocardium is stretched, however only a small portion of patients within the CHF group (study 3) had a high PCWP at rest. Nearly half of the study population with elevated NT-proBNP showed increased PCWP during PLL, which is indicative of underlying ventricular stiffness. By performing this preload increasing maneuver, patients predisposed to developing high filling pressure during supine cycling could be identified with high sensitivity and specificity. Echocardiography, in comparison with RHC, is more accessible, safer and requires less resources and time, thus is an appealing option in the quest to identify additional, non-invasive methods reflective of invasive pressures, which could be useful in the assessment of filling pressure during different loading conditions. LAVI at rest, LASRa and E/LVSRe during PLL, proved independently related to PCWP during PLL.
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| 10. |
- Tossavainen, Erik, et al.
(författare)
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Left Atrial Intrinsic Strain Rate Correcting for Pulmonary Wedge Pressure Is Accurate in Estimating Pulmonary Vascular Resistance in Breathless Patients
- 2016
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Ingår i: Echocardiography. - : Wiley-Blackwell. - 0742-2822 .- 1540-8175. ; 33:8, s. 1156-1165
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: We hypothesized that left atrial deformation during atrial systole (LASRa) correlates with pulmonary capillary wedge pressure (PCWP), thus enabling echo-derived pulmonary vascular resistance (PVR) estimation in a wide range of different subsets of patients.BACKGROUND: Various etiologies of pulmonary hypertension (PH) have different mechanisms and treatments for breathlessness. Irrespective of the location of the underlying pulmonary vascular pathology, pre- or postcapillary, the resulting PH is fairly easy to assess by Doppler echocardiography, but PVR remains a challenge.METHODS: We prospectively included 46 patients (mean age 61 ± 13 years) in sinus rhythm, who underwent right heart catheterization because of dyspnea. According to the NICE guidelines classification, 22 belonged to group 1 pulmonary artery hypertension (PAH), 19 belonged to group 2 congestive heart failure (CHF), 1 belonged to group 4 chronic thromboembolic pulmonary hypertension (CTEPH), and 4 had normal hemodynamics. Simultaneous Doppler echocardiography using spectral, tissue Doppler, and speckle tracking echocardiography techniques for assessing LA structure and function was performed.RESULTS: PCWPrhc correlated with LASRa (r(2) = 0.65, P < 0.001). PCWPecho was calculated using the equation (PCWPecho = 26.12 - 11.09 × LASRa), and the resulting PVR echo strongly correlated with the respective catheter-based measurements PVRrhc (r(2) = 0.69. P < 0.001) with a sensitivity of 85% and specificity of 74% identifying a PVR ≥ 3 WU.CONCLUSIONS: Left atrial strain rate during atrial systole correlates closely with pulmonary capillary wedge pressure and consequently the calculated pulmonary vascular resistance, irrespective of the etiology of PH.
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