الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Atherosclerosis Coronary artery atherosclerosis which is the principal cause of coronary artery disease is the single largest killer of both men and women, it is the leading cause of death in the developed world, and atherosclerosis is predicted to be the leading cause of death in the developing world within the first quarter of the next century.
Risk factor for coronary artery disease include hyperlipidemia, HT, DB, smoking, physical inactivity, obesity in additional to non-traditional risk factors and contributing risk factors like individual response to stress.
It has become clear that myocardial ischemia has a circadian pattern, with more ischemic episodes and infarctions occurring in the early morning, a number of physiologic changes during these hours may explain this phenomenon: lower blood fibrinolytic activity, greater platelet aggregability, higher plasma renin activity, a higher rate of cortisol excretion, and higher epinephrine and norepinephrine levels “catecholamines”
The nuclear myocardial scan is the best initial imaging study for the detection of myocardial ischemia; the wealth of research into nuclear scanning makes a strong case for its role as the best and preferred test for detecting myocardial ischemia. One of the important advantages of nuclear scanning is that it can be performed in all patients, the most commonly performed imaging procedure in nuclear cardiology is SPECT imaging of myocardial perfusion.
Transient ischemic dilation (TID) refers to an imaging pattern in which the left ventricular (LV) cavity appears larger on the stress images than at rest.
In some patients, substantial tracer uptake is apparent throughout the lung fields following stress that is not present at rest; lung uptake of thallium-201 has been more extensively validated than lung uptake of the Tc 99 m tracers SestaMIBI and tetrofosmin
Both lung uptake and TID provide clues to more extensive CAD than may have been suspected from the perfusion pattern alone. Both signs have been associated with angiographically extensive and severe CAD and with unfavorable long-term outcomes and thus are considered “high-risk” findings
In the present study we have evaluated forty patients presented to Alexandria University Hospital, Nuclear Cardiology Lab, for assessment of myocardial viability post myocardial infarction.
All patients included in this study were subjected to complete history taking, questionnaire to evaluate their anxiety about the SPECT study, complete clinical examination, 12 lead electrocardiograms, Echocardiography , plasma catecholamine level “two times” one in the early morning at 7:30 the second one three hours later , and Single Photon Emission computerized tomography.
Thallium rest myocardial perfusion SPECT with delayed resting study with reinjection protocol was used for all patients.