Ischemic Heart Disease (ihd)

Ischemic Heart Disease (IHD)
- a group of diseases caused by myocardial ischemia due to imbalance between
- coronary supply
- oxygen demand- more common in men
Types:
1- Angina pectoris (Most common- Myocardial infarction (MI- Chronic IHD
4- Sudden cardiac death (SCD)
Causes:
1- atherosclerotic occlusion
2- superimposed thrombosis (to AS)
3- vasospasm
Pathogenesis:
- occlusion
- inadequate coronary supply
- leading to insufficient oxygen and ischemia- obstruction of 70% to 75% or more causes symptomatic ischemia on exertion
- obstruction of 90% can cause symptomatic ischemia even at rest fibrosis
1- Angina pectoris:
- intermittent chest pain caused by reversible myocardial ischemia- three Types- Stable angina- Prinzmetal’s angina (Variant angina- Unstable angina
1- Stable angina:
- most common type- recurrent chest pain on increased physical activity- Pathogenesis: due to atherosclerotic occlusion (AS)
- ECG ST segment depression
2- Prinzmetal’s angina:
- chest pain occurring at rest
- Pathogenesis: due to coronary artery spasm- Stress ECG reveals ST elevation
3- Unstable angina:
- frequent bouts of chest pain at rest or with minimal exertion- may progress to acute MI
- Pathogenesis: due to superimposed partial thrombosis- Stress ECG is unsafe
2- Myocardial infarction
- ischemic myocardial necrosis due to occlusion of one or more of the main coronary arteries
Causes:
- atherosclerosis with occlusive thrombus
Pathogenesis:
- disruption of an atheromatous plaque- exposure subendothelial collagen
- thrombus formation occlusion ischemia infarction- MI occurs most commonly in the
LV and IVS
Morphology:
- during 0 to 24 hours
- Gross no changes Normal
Necrosis
- Microscopy coagulative necrosis without neutrophil infiltrate