| 1. |
- Strotmann, J. M., et al.
(författare)
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The effect of pacing-induced heart rate variation on longitudinal and circumferential regional myocardial function after acute beta-blockade a cardiac ultrasound study
- 2000
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Ingår i: European Journal of Echocardiography. - : Oxford University Press (OUP). - 1525-2167 .- 1532-2114. ; 1:3, s. 184-195
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To evaluate the effect of acute beta-blockade in combination with differing heart rates on longitudinal and circumferential regional myocardial function using Doppler myocardial imaging and two-dimensional-echocardiography. Methods and Results: In seven pigs the following echocardiographic indices were measured at baseline, after beta-blockade both without and with atrial pacing: wall thickening fraction, fractional shortening, myocardial peak systolic velocity, transmyocardial velocity gradient and systolic velocity time integral of the posterolateral wall in short-axis view; mitral valve plane excursion, myocardial peak systolic velocity and systolic velocity time integral of the posterolateral wall in an apical five-chamber view. Peak systolic velocities and velocity gradients decreased significantly following acute beta-blockade but no further decay occurred at high heart rate due to pacing. The velocity time integrals and mitral valve plane excursion showed a tendency to decrease following beta-blockade but only after pacing were they significantly reduced. The wall thickening fraction and fractional shortening showed a significant reduction after beta-blockade but no further decay after pacing. Conclusions: Changes in systolic velocities and velocity gradients were independent of heart rate reduction under high dosage beta-blockade, whereas wall thickening fraction, mitral valve plane excursion and velocity time integrals changed due to pacing.
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| 2. |
- Brodin, L A, et al.
(författare)
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[Hopeful future for echocardiography. Progress within both the function and perfusion areas].
- 2000
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 97:46, s. 5302-4, 5307
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Tidskriftsartikel (refereegranskat)abstract
- Echocardiography is presently a feasible method for quantitative estimation of intracardiac flows, pressure levels and for hemodynamic evaluation of valvular disease. The evaluation of regional myocardial function is still based on subjective scrutiny, and no routine method for the estimation of myocardial blood flow is available. We present an overview of newly developed techniques that are beginning to gain purchase in clinical practice. The use of native second harmonic imaging to improve image quality and of tissue Doppler to provide objective measurements of regional myocardial function is discussed. This article describes the transformation of tissue Doppler information into parametric images as in strain rate imaging, and overviews the use of ultrasound contrast agents. Used together with new imaging modalities, myocardial contrast echocardiography holds promise for future quantification of myocardial blood volume and flow. Other emerging echocardiographic technologies discussed are non-invasive measurement of coronary flow reserve and three dimensional cineloop visualization, developed to increase our understanding of cardiovascular physiological and anatomical coupling.
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