Ischemic Heart Disease

Ischemia

DemandSupply

Cause of Myocardial ischemia in

90% cases is

Atherosclerosis in

Coronaries

Clinical manifestations of IHD

It’s a spectrum

MI : Most severe ischemia

Angina pectoris : Ischemia Less ischemia

Chronic IHD

Sudden cardiac death

Ischemic Heart

Disease

Atherosclerosis in Coronaries

Atherosclerosis

Lifestyle

Obstructive lesion of 75% or greater causes symptomatic ischemia induced by exercise90% Obstruction can cause Symptoms at rest

Atherosclerosis

Acute MI

Sudden Cardiac Death

Acute Plaque change

Acute Plaque changes

Rupture

Erosion

Hemorrhage

Vulnerable Plaques

Plaques containing :

Large foam cells

High Lipid content

Thin Fibrous cap

Inflammatory cells

Angina pectoris

Attacks of substernal / precordial

chest discomfort causes by transient

myocardial ischemia that falls short

of infarction

Constricting

Squeezing

Knifelike

Patterns of Angina pectoris

1. Stable / Typical

2. Prinzmetal / Variant

3. Unstable / Crescendo

Myocardial Infarction

Heart Attack

Myocardial infarction – Death of cardiac

muscles due to ischemia

Transmural Infarcts – Involving full thickness

Of ventricular wall

Subendocardial infarcs – Involving inner

1/3 area of ventricular wall.

Males > Females

(till menopause)

Risk factors :

Pathogenesis

Sudden change in the Plaque

Adhesion of platelets to the exposed part

Platelets release : Thromboxane A2,

serotonin and Platelet factor 3 , 4

Vasospasm

Stimulation of Coagulation pathway

Thrombus blocks the coronary artery

90%

In 10% cases

Vasospasm

Emboli

?? Unexplained

Effects of MI on the Heart

End of Aerobic glycolysis

Start of Anaerobic glycolysis

Lactic acid accumulation

Ischemia for 20 – 40 mins :

Irreversible damage to myocytes

Coagulation Necrosis is the Mechanism

of cell Death of Myocytes …