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Stig Urheim

Bio: Stig Urheim is an academic researcher from Haukeland University Hospital. The author has contributed to research in topics: Medicine & Cardiology. The author has an hindex of 16, co-authored 31 publications receiving 3042 citations. Previous affiliations of Stig Urheim include University of Oslo & Oslo University Hospital.

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TL;DR: Myocardial strain by Doppler echocardiography may represent a new, powerful method for quantifying regional myocardial function and is less influenced by tethering effects than Dopplers tissue imaging.
Abstract: Background—Myocardial strain is a measure of regional deformation, and by definition, negative strain means shortening and positive strain, elongation. This study investigates whether myocardial strain can be measured by Doppler echocardiography as the time integral of regional velocity gradients, using sonomicrometry as reference method. Methods and Results—In 13 anesthetized dogs, myocardial longitudinal strain was measured on apical images as the time integral of regional Doppler velocity gradients. Ultrasonic segment-length crystals were placed near the left ventricular (LV) apex and near the base. Apical ischemia was induced by occluding the left anterior descending coronary artery (LAD), and preload was increased by saline. Percentage systolic strain by Doppler correlated well with strain by sonomicrometry (y=0.82x−1.79, r=0.92, P<0.01). During LAD occlusion, apical myocardium became dyskinetic, as indicated by positive strain values and negative Doppler velocities. At the LV base, myocardial strain...

1,112 citations

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TL;DR: The best evaluated strain parameter is global longitudinal strain (GLS) which is more sensitive than left ventricular ejection fraction (LVEF) as a measure of systolic function, and may be used to identify sub-clinical LV dysfunction in cardiomyopathies.
Abstract: Myocardial strain is a principle for quantification of left ventricular (LV) function which is now feasible with speckle-tracking echocardiography. The best evaluated strain parameter is global longitudinal strain (GLS) which is more sensitive than left ventricular ejection fraction (LVEF) as a measure of systolic function, and may be used to identify sub-clinical LV dysfunction in cardiomyopathies. Furthermore, GLS is recommended as routine measurement in patients undergoing chemotherapy to detect reduction in LV function prior to fall in LVEF. Intersegmental variability in timing of peak myocardial strain has been proposed as predictor of risk of ventricular arrhythmias. Strain imaging may be applied to guide placement of the LV pacing lead in patients receiving cardiac resynchronization therapy. Strain may also be used to diagnose myocardial ischaemia, but the technology is not sufficiently standardized to be recommended as a general tool for this purpose. Peak systolic left atrial strain is a promising supplementary index of LV filling pressure. The strain imaging methodology is still undergoing development, and further clinical trials are needed to determine if clinical decisions based on strain imaging result in better outcome. With this important limitation in mind, strain may be applied clinically as a supplementary diagnostic method.

571 citations

Journal ArticleDOI
Thor Edvardsen1, Helge Skulstad1, Svend Aakhus1, Stig Urheim1, Halfdan Ihlen1 
TL;DR: The new SDE approach might be a more accurate marker than TDE for detecting systolic regional myocardial dysfunction induced by LAD occlusion and reduced velocities in all septal segments during angioplasty.

264 citations

Journal ArticleDOI
TL;DR: Postsystolic shortening is a relatively nonspecific feature of ischemic myocardium and may occur in dyskinetic segments by an entirely passive mechanism, however, in segments with systolic hypokinesis or akinesis, postsyStolic shortens is a marker of actively contracting myocardia.
Abstract: Background— Postsystolic shortening in ischemic myocardium has been proposed as a marker of tissue viability. Our objectives were to determine if postsystolic shortening represents active fiber shortening or passive recoil and if postsystolic shortening may be quantified by strain Doppler echocardiography (SDE). Methods and Results— In 15 anesthetized dogs, we measured left ventricular (LV) pressure, myocardial long-axis strains by SDE, and segment lengths by sonomicrometry before and during LAD stenosis and occlusion. Active contraction was defined as elevated LVP and stress during postsystolic shortening when compared with the fully relaxed ventricle at similar segment lengths. LAD stenosis decreased systolic shortening from 10.4±1.2% to 5.9±0.9% (P<0.05), whereas postsystolic shortening increased from 1.1±0.3% to 4.2±0.7% (P<0.05). In hypokinetic and akinetic segments, LV pressure–segment length and LV stress–segment length loop analysis indicated that postsystolic shortening was active. LAD occlusion ...

245 citations

Journal ArticleDOI
TL;DR: It is indicated that peak ejection velocity is an inappropriate measure of function in severely ischemic myocardium, and therefore IVC and IVR velocities are better markers of function.
Abstract: Background— Tissue Doppler imaging (TDI) is a potentially powerful method for diagnosing myocardial ischemia. This study was designed to investigate how velocity patterns in ischemic myocardium relates to regional function, and to determine whether timing of velocity measurements relative to ejection and isovolumic phases may increase the diagnostic power of TDI. Methods and Results— In 17 open-chest anesthetized dogs we measured pressures by micromanometers, myocardial longitudinal segment lengths by sonomicrometry, and velocities by TDI. Myocardial longitudinal strain rate was calculated as velocity divided by distance to the left ventricle apex. Moderate ischemia (left anterior descending coronary artery stenosis) caused parallel reductions in regional systolic shortening by sonomicrometry (P<0.05) and in peak systolic velocities by TDI (P<0.05). Severe ischemia (left anterior descending coronary artery occlusion), however, induced systolic lengthening by sonomicrometry (P<0.001), whereas peak TDI velo...

215 citations


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Journal ArticleDOI
TL;DR: Recommendations for the evaluation of left ventricular diastolic function by echocardiography are made and further research is needed to determine the best method for this evaluation.
Abstract: Recommendations for the evaluation of left ventricular diastolic function by echocardiography

4,162 citations

Journal ArticleDOI
TL;DR: The assessment of left ventricular (LV) diastolic function and filling pressures is of paramount clinical importance to distinguish this syndrome from other diseases such as pulmonary disease resulting in dyspnea, to assess prognosis, and to identify underlying cardiac disease and its best treatment.
Abstract: The assessment of left ventricular (LV) diastolic function should be an integral part of a routine examination, particularly in patients presenting with dyspnea or heart failure. About half of patients with new diagnoses of heart failure have normal or near normal global ejection fractions (EFs). These patients are diagnosed with “diastolic heart failure” or “heart failure with preserved EF.”1 The assessment of LV diastolic function and filling pressures is of paramount clinical importance to distinguish this syndrome from other diseases such as pulmonary disease resulting in dyspnea, to assess prognosis, and to identify underlying cardiac disease and its best treatment. LV filling pressures as measured invasively include mean pulmonary wedge pressure or mean left atrial (LA) pressure (both in the absence of mitral stenosis), LV end-diastolic pressure (LVEDP; the pressure at the onset of the QRS complex or after A-wave pressure), and pre-A LV diastolic pressure (Figure 1).Although these pressures are different in absolute terms, they are closely related, and they change in a predictable progression with myocardial disease, such that LVEDP increases prior to the rise in mean LA pressure. Figure 1 The 4 phases of diastole are marked in relation to high-fidelity pressure recordings from the left atrium (LA) and left ventricle (LV) in anesthetized dogs. The first pressure crossover corresponds to the end of isovolumic relaxation and mitral valve opening. In the first phase, left atrial pressure exceeds left ventricular pressure, accelerating mitral flow. Peak mitral E roughly corresponds to the second crossover. Thereafter, left ventricular pressure exceeds left atrial pressure, decelerating mitral flow. These two phases correspond to rapid filling. This is followed by slow filling, with almost no pressure differences. During atrial contraction, left atrial pressure again exceeds left ventricular pressure. The solid arrow points to left ventricular minimal pressure, the dotted arrow to left ventricular …

3,659 citations

Journal ArticleDOI
TL;DR: The primary goal of this update is to simplify the approach and thus increase the utility of the guidelines in daily clinical practice.
Abstract: Echocardiographic assessment of left ventricular (LV) diastolic function is an integral part of the routine evaluation of patients presenting with symptoms of dyspnea or heart failure. The 2009 American Society of Echocardiography (ASE) and European Association of Echocardiography (now European Association of Cardiovascular Imaging [EACVI]) guidelines for diastolic function assessment were comprehensive, including several two-dimensional (2D) and Doppler parameters to grade diastolic dysfunction and to estimate LV filling pressures.1 Notwithstanding, the inclusion of many parameters in the guidelines was perceived to render diastolic function assessment too complex, because several readers have interpreted the guidelines as mandating all the listed parameters in the document to fall within specified values before assigning a specific grade. The primary goal of this update is to simplify the approach and thus increase the utility of the guidelines in daily clinical practice. LV diastolic dysfunction is usually the result of impaired LV relaxation with or without …

2,541 citations

Journal ArticleDOI
TL;DR: Statistical shape models (SSMs) have by now been firmly established as a robust tool for segmentation of medical images as discussed by the authors, primarily made possible by breakthroughs in automatic detection of shape correspondences.

1,402 citations

Journal ArticleDOI
TL;DR: Speckle tracking echocardiography provides accurate and angle-independent measurements of LV dimensions and strains and has potential to become a clinical bedside tool for quantifying myocardial strain.

1,236 citations