1. Ischemic Heart Disease
By :Dawit Ayele
(MD,Internist)

2. Ischemia •Greek ischein“to restrain” + haima“blood”
•Ischemia occurs when the blood supply to a tissue is inadequate to meet the tissue’s metabolic demands

3. Causes of Ischemia: Decreased Supply
•Vascular insufficiency: –Atherosclerosis –Thrombosis –Embolism –Torsion –Compression
Hypotension:
–Shock…

4. Causes of Ischemia: Increased Demand
•Increased tissue mass (hypertrophy) •Increased workload (tachycardia, exercise) •Increased tissue “stress” (cardiac dilatation)

5. Myocardial Ischemia: Occurs when myocardial oxygen demand exceeds myocardial oxygen supply

6. Effect of Ischemia •Ischemia has 3 principal biochemical components:
–Hypoxia (including anoxia)
–Insufficiency of metabolic substrates
–Accumulation of metabolic waste
Effect Depends on:
Severity and Duration of Injury
Cell Type
Microvascular Anatomy

7. Infarction
•Latin infarctus, pp. of infarcire“to stuff” •An infarct is an area of tissue/organ necrosis caused by ischemia •Infarctions often result from sudden reduction of arterial (or occasionally venous) flow by thrombosis or embolism •Infarctions can also result from progressive atherosclerosis, spasms, torsions, or extrinsic

8. Morphology of Infarcts
•Infarcts can be anemic (white) or hemorrhagic (red) •White infarcts occur with arterial occlusion of solid organs •Red infarcts occur with venous occlusion or with arterial occlusions in organs with double or collateral circulation •White infarcts can become hemorrhagic with reperfusion

9. Ischemic Heart Disease (IHD)
•Angina pectoris, myocardial infarction, sudden cardiac death, chronic IHD with congestive heart failure •IHD is the leading cause of death in the US and developed countries •Every year in the US, ~1.5 million have an MI and ~600,000 die from ischemic heart disease •Atherosclerosis of the major coronary arteries is responsible for the vast majority of the cases of ischemic heart disease

10. Major Coronary Arteries:normal anatomy

11. Acute Myocardial Infarction (MI)
•MI indicates the development of an area of myocardial necrosis •MI’s are typically precipitated by an acute plaque change followed by thrombosis at the site of plaque change •Acute plaque changes include fissuring, hemorrhage into the plaque, and overt plaque rupture with distal embolism •Most unstable plaques are eccentric lesions rich in T cells and macrophages, and have a large, soft core of necrotic debris and lipid covered by a thin fibrous cap
Acute Myocardial Infarction (MI)

12. Risk Factors family History cigarette smoking diabetes mellitus
hypertension
hyperlipidemia
sedentary life-style
obesity
elevated homocysteine, LP-a ?

13. Clinical Feature Suggestive features Different descriptions
Site & radiation:
Typical episode:
Angina equivalents:
Physical exam: risk factors for CAD
or cardiac findings of d/t extent

14. Features suggesting absence of angina pectoris
Pleuritic
Pain localized to tip of one finger
Reproducibility by movement or chest palpation
Constant pain lasting many hours or very brief in seconds
Pain radiating to lower extremities

15. Differential diagnosis of chest pain according to location where pain starts.

16. Investigation Supportive Diagnostic Urine analysis—DM&Renal dis
Lipid profileinine
Hematocrit
Glucose
Creatinine
Thyroid function test
Chest X-ray
Diagnostic
Cardiac enzymes-Cpk,troponin
ECG
Stress test
Coronary angiography

17. Management plan-should consist of:
1)Explanation & reassurance
2)Identification & treatment of aggravating conditions
3)Adaptation of activity
4)Treatment of risk factors
5)Drug therapy for angina and cardiac complications
6)Consideration of mechanical revascularization
Note: IHD needs high index of suspicion , early consultation and referral to cardiac center or hospital with support(Oxygen, NSAIDs, nitroglycerin....)

18. Thanks