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Atherosclerotic and Ischemic Heart Disease. Howard L. Sacher, D.O. Long Island Cardiology and Internal Medicine. Pathophysiology. Classification of vascular injury is divided into 3 types: Type I functional alteration
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Atherosclerotic and Ischemic Heart Disease Howard L. Sacher, D.O. Long Island Cardiology and Internal Medicine
Pathophysiology • Classification of vascular injury is divided into 3 types: • Type I functional alteration • Type II Endothelial and Intimal damage, the internal elastic lamina is preserved • Type III Deep injury involving the intima and media. The lamina is not preserved
After Type I injury the endothelium’s ability to release intrinsic relaxing substances
Proposed scenario of EDRF and Endothelin during ischemic syndromes
ACh decreases as risk factors increase, decreasing the smooth muscles’ ability to relax
Smooth Coronary artery segment that shows EDRF dependent dilation to ACh will also dilate with exerciseBut when evaluating coronary segments that where irregular and stenosed, they did not show EDRF dependent dilation to ACH. These did not dilate with exercise
Adenosine • Thought to act on the coronary vasculature by stimulating the Adenosine A2 receptors on the smooth muscles. • Adenosine crosses the endothelial barriers to stimulate the Endothelial Independent Pathway for vasodilatation
The hypokinetic inferior and akinetic apical wall is shown to improve several months after revascularization
Who benefits from Diagnostic testing from this last graph? • A Pt with a low pre-test probablity of disease will continue to have a low likelihood of disease regardless of a (-) test • A Pt with a high pre-test probability of disease will continue to have a high likelihood of disease regardless of a (-) test • Diagnostic testing is most beneficial for those Pt’s with intermediate probability for disease
Patient with Basilar Septal ischemia evidenced by decreased tracer uptake at STR with increased uptake at RST
With a completely reversible Septal wall toward the Anterior segments of the ventricle on HLA
Ischemia that is a result of Stress is dynamic with cascade of events, pain and ECG changes are seen late in the game
Moral of story is to revascular for the greatest reduction in long term mortality
Patient has significant multivessel disease – MIBI reveals a inferior wall infarction with septal and anterior wall ischemia. Areas of the inferoseptal walls may also reveal some peri-infarct ischemia
Most important factor in Myocardial Oxygen demand is Heart Rate • 2nd Most important factor is Left Ventricular Wall Tension • LVWT is related to mean pressure during systole, LV volume and contractility • Inc. LVWT = Inc resistance to coronary flow with concomitant Inc. in O2 demand
Hint: know thisTrinitrogylcerin and Isosorbide are directly active as -ONO2. -ONO2 is then converted to nitric oxide which acts both pre and post synaptically to vasodilate