The emerging role of exercise testing and stress echocardiography in valvular heart disease. Abnormal vascular response to exercise is an important contributor to the diminished stroke output and possibly to the development of effort-related symptoms in AS patients. Five-year survival was higher in operated patients compared to those medically treated, despite a high operative mortality.
Exercise testing and exercise stress echocardiography in asymptomatic aortic valve stenosis.
The ability of exercise testing to identify asymptomatic patients with severe AS who are likely to develop adverse events was assessed in a meta-analysis of data from seven studies with a total of patients mean age years. Dizziness during a treadmill test has a higher positive predictive value for development of symptoms during the next year. The occurrence of rapidly reversible dyspnea at high workloads is considered to be normal. Impact of impaired myocardial deformations on exercise tolerance and prognosis in patients with asymptomatic aortic stenosis.
Determinants of an abnormal response to exercise in patients with asymptomatic valvular aortic stenosis. Patients with decrease or smaller increase in LV ejection fraction during exercise were more likely to develop a clinical abnormal exercise response and cardiac events. In addition to its role in distinguishing between true stenosis and pseudostenosis, low-dose dobutamine echocardiography is helpful in risk strafying patients with severe true AS and in determining the appropriate therapy.
Absence of contractile reserve, baseline pressure gradient of 20 mmHg or less and associated coronary artery disease are predictors of high operative mortality.
What is a dobutamine stress echocardiogram?
Restrictive annuloplasty for ischemic mitral regurgitation may induce functional mitral stenosis. In patients undergoing surgical correction of ischemic mitral regurgitation MR , a restrictive annuloplasty combined with coronary artery bypass grafting is the most common approach. However, this procedure is associated with a relatively high rate of recurrence of MR, and restrictive annuloplasty may result in functional MS in some patients. Importance of left ventricular longitudinal function and functional reserve in patients with degenerative mitral regurgitation: assessment by two-dimensional speckle tracking.
The results of this study suggest that 2D strain obtained during exercise could be useful to better identify contractile reserve in these patients. An increase of less than 1. Prognostic importance of quantitative exercise Doppler echocardiography in asymptomatic valvular aortic stenosis. Quantitative Doppler exercise echocardiography could be useful to identify a high-risk subset of patients with asymptomatic valvular aortic stenosis and help for clinical decision making. Stress testing in valve disease.
Deformation Stress Echocardiography. Myocardial deformation imaging based on ultrasonic pixel tracking to identify reversible myocardial dysfunction Becker M, Lenzen A, Ocklenburg C, Stempel K, Kuhl H, Neizel M, Katoh M, Kramann R, Wildberger J, Kelm M, Hoffmann R Comment: In myocardial infarction, transmural extension or scar distribution in the infarct zone is proportionally related to the reduction in systolic function measured by the radial transmural velocity gradient or strain-rate imaging or peak radial strain using the speckle-tracking techniques.
Detection of postischemic regional left ventricular delayed outward wall motion or diastolic stunning after exercise-induced ischemia in patients with stable effort angina by using color kinesis. The quantification of dipyridamole induced changes in regional deformation in normal, stunned or infarcted myocardium as measured by strain and strain rate: an experimental study Marciniak M, Claus P, Streb W, Marciniak A, Boettler P, McLaughlin M, D'Hooge J, Rademakers F, Bijnens B, Sutherland GR Comment: Experimental studies show that parameters derived from strain-rate imaging can be helpful in identifying and quantifying ischemia-induced myocardial abnormalities and in identifying viable myocardium, whose strain rate is normalized in stunned areas following inotropic challenge with dobutamine or dipyridamole.
Reference: Int J Cardiovasc Imaging ; Speckle-derived strain a better tool for quantification of stress echocardiography? Abraham TP, Pinheiro AC Comment: Some disadvantages of speckle tracking are the lower frame rate in comparison with TDI, influenced by image quality, examination of strain rather than strain rate, and reduced combination with contrast echocardiography for enhancement of border detection. Comment: Coronary flow reserve in coronary artery disease is feasible, useful, and prognostically validated tool to be considered with standard wall motion analysis; It is currently recommended as the state-of-the art method with vasodilatory stress echocardiography when adequate technology and expertise are available.
Reference: Am J Hypertens ; Prognostic value of left-ventricular and peripheral vascular performance in patients with dilated cardiomyopathy Bombardini T, Nevola E, Giorgetti A, Landi P, Picano E, Neglia Comment: Coronary blood flow increases three- to fourhold in normal subjects, but the reduction in diastolic time much greater than shortening in systolic time limits mostly the perfusion in the subendocardial layer — whose perfusion is mainly diastolic, whereas the perfusion in the subepicardial layer is also systolic.
Reference: J Nucl Cardiol ; When a 4-D data set is acquired, the cropping and segmentation of the data set can be performed after the study to ensure that views are comparable and reproducible. Finally, the issue of poor image quality can be overcome by the utilisation of ultrasound contrast agents.
While contrast echo has been widely used during stress 2-D echocardiography, there has been little data on its applicability during 4-D and multidimensional stress echo. However, contrast specific imaging software has been incorporated within the image processing for multidimensional or 4-D echo, allowing excellent high-definition images with superb endocardial enhancement to be obtained in even the most difficult echo subjects.
Sugegn et al. Heart rate decreases very rapidly following the end of exercise when even a difference of 10 seconds during acquisition could be significant. For example, average peak heart rate at the end of bi-plane acquisition was beats per minute, whereas with conventional 2-D imaging the peak heart rate was beats per minute. It is self evident that by using multidimensional tri-plane imaging, as opposed to bi-plane imaging, even greater reductions in imaging time, and therefore higher post-stress heart rates and sensitivity, would be achieved. The principle for this was also shown in a paper by Dagianti et al.
When utilising the latter modality, imaging is performed while the patient continues to exercise and therefore there is no drop in heart rate. In patients who underwent conventional treadmill exercise, stress echo-significant reductions in the degrees of wall motion and thickening abnormalities were seen in patients with one and two vessel disease highlighting the reduced sensitivity that results.
Because multidimensional imaging significantly reduces the acquisition time, sensitivity should be improved.badgecourses.com/4855-best-cell-phone.php
Role of Stress Echocardiography to Diagnose CAD: When and In Whom? - The Cardiology Advisor
The time taken from the end of the exercise to acquisition of the three apical scan planes using tri-plane imaging was 42 seconds, whereas when conventional 2-D echo was used the mean time was 65 seconds, as shown in Figure 2. All imaging was performed by the same experienced sonographer. This meant that the peak heart rate achieved with multidimensional tri-plane echo was beats per minute, whereas by the time the imaging had finished with conventional 2-D echo it had fallen to beats per minute.
This was a highly significant reduction as shown in Figure 3. Modern stress echo reporting software incorporates the ability to compare the same scan plane at different stages during the stress echo. This can now be achieved with the software incorporated into state-of-the-art scanners.
For example, the three scan planes acquired at base line and peak exercise echo will be digitally stored and then automatically sorted by the software so that the base line and peak stress images from the same view can be visualised side by side. In addition, the 4-D data set can be semi-automatically separated into nine short axis slices running from the base to the apex. This facilitates detailed evaluation of every myocardial segment. Comparison of changes of stress-induced changes can be made by looking at the different short axis slices side by side.
A mathematical model or cast of the left ventricle can be created from the multi-plane images and this can be animated to provide a graphical 3-D display of myocardial contraction. The technologist will place warmed gel on your chest and then place the transducer on the gel.
What is stress echocardiography?
You will feel a slight pressure as the technologist positions the transducer to get the best image of your heart. The dobutamine infusion will begin at a rate determined by your weight. The rate of the infusion will be increased every few minutes until you have reached your target heart rate determined by the doctor based on your age and physical condition , or until the maximum dose of dobutamine has been reached.
After the dobutamine is started and after each increase in the dobutamine, your blood pressure will be checked, an ECG tracing will be done, and echocardiogram images will be recorded. The technologist will move the transducer around on your chest so that all areas and structures of your heart can be seen.
Once you have reached your target heart rate or the maximum amount of the dobutamine, the medicine will be stopped. Your heart rate, blood pressure, and ECG will continue to be monitored for 10 to 15 minutes until they have returned to the baseline state. Final echocardiogram pictures will be taken.
Tell the technologist if you feel any chest pain, trouble breathing, sweating, or heart palpitations at any time during the test. Once all the images have been taken, the technologist will wipe the gel from your chest, remove the ECG pads, and take out the IV line. You may then put on your clothes. Generally, there is no special type of care following a dobutamine stress echocardiogram.
However, your doctor may give you other instructions after the test, depending on your particular situation.
A DSE may involve one or more of these special types of echocardiograms: M-mode echocardiogram. Why might I need a dobutamine stress echocardiogram? Possible reasons for getting a dobutamine stress echocardiogram DSE may include: To assess the heart's function and structures To further assess the degree of known heart valve disease To determine limits for safe exercise before you start a cardiac rehabilitation program or are recovering from a cardiac event, such as a heart attack myocardial infarction, or MI or heart surgery To evaluate the cardiac status before heart surgery There may be other reasons for your doctor to recommend a DSE.
What are the risks of a dobutamine stress echocardiogram? Possible risks associated with a dobutamine stress echocardiogram DSE include: Chest pain Severely high blood pressure Irregular heartbeats Dizziness Nausea Extreme tiredness Heart attack rare There may be other risks depending on your specific medical condition. Certain factors or conditions may interfere with a DSE such as: Smoking or using any other form of tobacco within 3 hours of the test Ingesting caffeine within 3 hours of the test Taking beta-blocking medicines — these may make it hard to increase the heart rate to an appropriate level.
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- How the Test is Performed.
How do I get ready for a dobutamine stress echocardiogram? Your doctor will explain the test to you and let you ask questions. Tell the doctor if you are allergic to or sensitive to any medicines or latex. Your doctor will give you specific instructions Tell your doctor if you are pregnant or think you could be. Tell your doctor if you have a pacemaker. Based on your medical condition, your doctor may request other specific preparation.