الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 119 |  |  |
| | | from | 119 | | |
Abstract
BACK GROUND:
Diabetes mellitus is a major cardiovascular risk factor, increasing cardiovascular mortality two to three-fold in affected subjects. However, only recently has the need for aggressive treatment of diabetic patients due to their high risk of cardiovascular disease (CVD) been emphasized. An important impetus has come from the observation that diabetic patients without ischaemic heart disease (IHD) show an incidence of cardiovascular death, myocardial infarction (MI) and stroke similar to nondiabetic subjects with previous MI. Moreover many studies have reported that the premenopausal protection against coronary heart disease seen in healthy women is lost in those with diabetes. Therefore, diabetes should be considered as a cardiovascular disease in terms of cardiovascular prevention. The pathophysiological mechanism underlying the increased susceptibility to CVD of diabetic patients resides in their more advanced and widespread diffusion of atherosclerosis, as well as on a hypercoagulability condition
OBJECTIVES:
The aim of this work was to compare the ability of detection of silent myocardial ischemia in young insulin-dependant diabetic patients, having no evidence of ischemic heart disease, by Treadmill exercise stress test versus Thallium 201 SPECT study.
METHODS:
This study included 15 diabetic subjects whom were selected according to the following criteria :
Young insulin-dependant diabetics below 35 years of age.
No history of any cardiac symptoms or documented ischemic heart disease, nor cerebrovascular or peripheral vascular disease.
No clinical evidence of any cardiac disease.
Normotensives and not on antihypertensive drugs.
Are capable of performing treadmill exercise test with no physical disability.
Normal resting ECG.
Normal Echocardiographic examination regarding ventricular function and wall motion.
RESULTS:
Fifteen patients with type I diabetes mellitus were included in this study; they were all males. Their age ranged from 20-34 years with a mean of 27.9±2.7 years. Their height ranged from 150-181 cm with a mean of 163.21±10.44 cm . Their weight ranged from 45-75 kg with a mean of 62.51±9.89 kg. None had a family history of ischemic heart disease and they were all smokers of a duration ranging from 4-15 years with a mean of 6.94 ±2.5 years. The duration of diabetes ranged from 4-13 years with a mean of 7±2.29 years. Treadmill exercise stress test was carried out for all the patients until reaching at least 85% of the predicted maximal heart rate; none of the patients showed any significant ST-segment deviation or any of the criteria mentioned before to report a positive stress ECG. On the other hand after analyzing the stress and rest images of the thallium-201 SPECT studies; 8 (53.3%) of the patients showed a significant reversible perfusion defect. Five (62.5%) patients had an exercise thallium-201 SPECT study revealing a perfusion defect involving the inferior wall and septum from above mid-cavity up to the base seen in short, vertical and horizontal long axes tomographic cuts with complete redistribution in the delayed resting study; denoting ischemia in the RCA territory. While two patients (25%) revealed a perfusion defect in the initial stress study involving the anteroseptal wall from above mid cavity up to the base seen in short, vertical and horizontal axes tomographic cuts with complete redistribution in the delayed resting study consistent with ischemia in the LAD territory. One patient (12.5%) had a perfusion defect, in the initial stress study, involving the anterior wall from above the apex up to the base seen in short, vertical and horizontal tomographic cuts while the delayed resting study showed complete redistribution consistent with ischemia in the LAD territory. All patients had a normal LV size and normal lung thallium uptake during rest and stress.
CONCLUSIONS
DM is a major risk factor for CAD being more prevalently silent, and its presence is augmented by the clustering of other CV risk factors. Tl-201 SPECT MPI is a more sensitive modality for the detection of SMI in diabetic subjects when compared with stress ECG testing and provides additional information regarding localization, quantification and reversibility of the ischemic territory of the myocardium as well as evaluation of the systolic function. Nevertheless the specificity of Tl-201 SPECT imaging may be much underestimated when considering the presence of endothelial dysfunction and microvasculopathy in diabetic patients having angiographically normal epicardial structure.