Ischemia & MI

• Ischemia & MI
• Ischemia
• Types of Ischemia
• Myocardial Infarction
• Markers of MI
• Treatment of MI

Ischemia

• partial occlusion of Coronary artery
• Relieved by drugs and in Stable angina(rest)

Types of Ischemia

1. Stable Angina
2. Unstable Angina
3. Trans mural Angina

---

Myocardial Infarction

• Complete occlusion of Coronary Artery / Partial occlusion leads to irreversible injury

Markers of MI

Marker	Detection time	Peak	Return into Normal
Troponin 1	2-4 hrs	24 hrs	7-10 days
CK-MB	4-6 hrs	24 hrs	72 hrs(detect second MI)

Treatment of MI

	Prevent Clot Formation	Break old Clots	Supportive Treatment
	loading dose Aspirin/Heparin =>(Aspirin - Prevent TXA2to stop platelet aggregation) (Heparin - block Secondary Hemostatsis)	Fibrinolysis/Angioplasty	Nitrates (low Preload)
			ACEI (blocks NA reabsorption) (inhibit Angiotension TPR increase)
			- blocker (reduce heart rate)

Time	Gross	Microscopic	Complications
0-4 hrs	none	none	Cardio-genic Shock, Congestive failure arrhythmia if conduction system infarction
4-24hrs	Dark discoloration	Coagulative Necrosis	Arrhythmia
1 - 3 days	Yellow pallor	Neutrophils	If STEMI risk of Fibrous Pericarditis
4- 7 days	Yellow Pallor	Macrophage eats dead tissue	Papillary muscles damage if Right Coronary artery infarction Rupture of Ventricular free wall if Infarction of Ventricular walls intraventricullar septum
1-3 weeks	Red border (new blood vessels forming and bringing fibroblasts)	Granual;tion tissue formation ,collagen deposition
1 month	White scar	Fibrosis	Loss of Tissue function leads to Aneurysm mural thrombosis dressler syndrome if STEMI (Antibodies against pericardium)