الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
 |  | from | 178 |  |  |
| | | from | 178 | | |
Abstract
To evaluate the reliability of dobutamine - stress echocardiography in assessment of haemodynamic status of patients with moderate to sever mitral stenosis and its value in clinical decision making, 30 patients (20 women their ages ranged from 21 to 48 years and 10 males their ages ranged from 17 to 35 years) were studied.
All patients had rheumatic moderate to severe mitral valve ’stenosis with mitral valve area 1 - 1.5cm2. Those patients who suffered from more than mild mitral regurge, mild aortic regurge, mild aortic stenosis and those who suffered from hypertension, advanced heart failure as well as pregnant patients and those with poor chest echogenicity were excluded from the study.
All patients were subjected to full history taking, complete clinical examination, twelve leads electrocardiogram, basic echo-Doppler examination, Dobutamine stress Doppler echocardiography and exercise-stress Doppler echocardiography.
M-mode echocardiography was performed to obtain chamber dimentions, mitral leaflets thickness and mobility and left ventricular systolic function using the fractional shortening and ejection fraction equations.
Two - dimentional echocardiography was done for measurement of mitral valve area by planimetry, assessment of structural changes in mitral valve apparatus using the mitral valve scoring system which includes
Summary - 132-
valvular mobility, valvular thickness, valvular calcification and subvalvular affection. It was also done for assessment of global and segmental left ventricular wall motion abnormalities as well as for exclusion of pericardial diseases and left atrial thrombosis.
Doppler echocardiography involving pulsed and continuous wave Dopplers as well as colour flow imaging was performed at the time of two-dimentional echocardiographic examination and the following echo-Doppler measurements were carried out.
1-Mital valve area using pressure half time method.
2-Mean and peak mitral diastolic gradients through planing of the mitral diastolic flow and depending on the modified Bernoulli equation.
3-Calculation of systolic pulmonary artery pressure using tricuspid regurgitant jet plus right atrial pressure method.
4-Calculation of mean pulmonary artery pressure utelizing pulmonary flow acceleration time (mean pulmonary artery pressure = 90 - (62% of acceleration time).
After complete echo-Doppler examination and obtaining the above measurements at rest, dobutamine - stress echo was then done. Dubutamine infusion was begun at an initial dose of 5pg/Icg/min The dose was increased every 3 minutes by 5μg/kg/min untill the heart rate exceeds the basic rate by 30 beats/min or reaches 110 beats/min or untill a maximum dose of 40 μg/kg/min. Mitral pressure gradient and systolic and mean pulmonary artery pressures were then estimated again.
In separate situations, all patients underwent symptom limited treadmill exercise with continuous electrocardiographic recording
Summary - 133-
according to the modified Bruce protocol. Immediately after maximal treadmill exercise mitral pressure gradient and pulmonary artery pressure were estimated by echo - Doppler again.
Statistical analysis of the results of the present study revealed the following :
1-There was significant increase of mean mitral pressure gradient and mean pulmonary artery pressure after both peak dobutamine infusion and symptom limited treadmill exercise.
2-There was positive correlation between the increase of mitral pressure gradient and pulmonary artery pressure after both peak dobutamine infusion and treadmill exercise.
3-There was no correlation between mitral valve area and both mitral pressure
gradient and pulmonary artery pressure during rest but there was inverse correlation after both dobutamine infusion and treadmill exercise.
4-There was positive correlation between mitral valve area and duration of treadmill exercise.
5-There was positive significant relationship between functional classes and both mitral pressure gradient and pulmonary artery pressure during rest and after dobutamine infusion and treadmill exercise.
6-There was inverse significant relation between functional classes and duration of treadmill exercise.
7-There was positive correlation between left atrial dimentions and mitral pressure gradient and pulmonary artery pressure during rest and after both dobutamine infusion and treadmill exercise.
8-There was no significant difference of the mitral pressure gradient and pulmonary artery pressure between AF (n : 8) and sinus rhythm (n : 22) group