3. Introduction-
IHD also known as coronary heart disease, coronary
artery disease
IHD is defined as acute or chronic for cardiac disability
arising from imbalance between myocardial supply and
demand for oxygenated blood
Since narrowing or obstruction Of coronary artery
system is the most common cause of myocardial
anoxia
4.
5. Etiopathogenesis -
It is convenient to consider the etiology of IHD
under there broad headings:
1. Coronary atherosclerosis
2. Superadded changes in coronary atherosclerosis; and
3. Non – atherosclerotic causes
6. Coronary atherosclerosis -
Coronary atherosclerosis resulting in fixed obstruction is the major
cause of IHD in more than 90% cases
Distribution – highest incidence in the anterior descending branch
of left coronary artery, followed in descending frequency by the right
coronary artery and still less in circumflex branch of left coronary
> 75% occlusion causes symptomatic ischemia included by exercise
Location – area of severe involvement is 3-4 cms from coronary
ostia, most often at/ near the bifurcation
Slowly developing atheromas over long periods Lead yo collateral
circulation
7.
8. Super added changes in coronary
atherosclerosis -
Acute coronary syndrome are precipitated by
changes superimposed on pre- existing fixed
coronary atheroma
Haemorrage : causes volume expansion
Fissuring,ulceration- exposure of highly
thrombogenic subendothelial tissues of blood
Local platelets aggregation plug – which release
thrombaxaneA2 ( vasospasmic mediator)
responsible for coronary vasospasm
Thrombosis, emboli,microinfacts
9. Non-atherosclerotic causes -
Vasospasm – despite no significant atherosclerotic
coronary narrowing may cause angina / M.I
1. Circulating adrenergic agonist’ s
2. Local released content of platelets
3. Decrease secretion of relaxing factors
Stenosis of coronary ostia – from syphilitic aortitis
Arteritis – polyarteritis nodosa, tuberculosis and other
bacterial infection
Thrombotic disease- sickle cell anaemia ,polycythaemia
vera, : hypercoagulability of blood – coronary occlusion
Trauma
10. Risk factors-
High blood pressure
Smoking
Obesity
High blood cholesterol
Lack of exercise
Diabetes
11. Effects of myocardial ischemia -
CORONAR ARTERY Disease
1. Asymptomatic state
2. Angina pectoris
3. Acute myocardial infarction
4. Chronic ischemic heart disease
5. Sudden cardiac death
13. INTRODUCTION-
MI is defined as a diseased condition which is caused
by reduced blood flow in coronary artery due to
atherosclerosis and occlusion of an artery by an
embolus or thrombus
MI or heart attack is the irreversible damage of
myocardial tissue caused by prolonged ischemia and
hypoxia
14.
15. Types of infarcts-
According to anatomic region of left ventricle
involved-
1. Anterior
2. Posterior
3. Lateral
4. Septal
5. Circumferential
6. Combinations-
anterolateral,posterolateral,anteroseptal
16. According to degree of thickness of ventricular wall
involved-
1. Transmural ( full thickness)
2. Laminar ( Subendocardial)
According to age of infarcts-
1. Newly formed ( acute,recent,fresh)
2. Advanced infarcts ( old,healed, organised)
17. EPIDEMIOLOGY-
In industrial countries MI accounts of 10-25% of all death’s
Incidence is higher in elderly people about, 5% occurs at
people under the age 40
Male have higher risk
Women during reproductive period have low risk
Over last 30 years, the rate of disease increase from 2-3
rural population and 4-12% in urban population
19. Gender
Diabetes
Hyperlipoproteinaemia
Family history of ischemic heart disease
20. ETIOPATHOGENESIS-
The etiologic role of severe coronary atherosclerosis ( more than 75% compromise of lumen)
of one or more of the three major coronary arterial trunks in the pathogenesis of about 90%
cases of acute MI is well documented by autopsy studies as well as by coronary angiographic
studies. A few notable features in etiology and pathogenesis of acute MI are considered
below:
1. Mechanism of myocardial ischemia
2. Role of platelets
3. Acute plaque rupture
4. Non- atherosclerotic cause
5. Transmural versus subendocardial infarcts
Complications
1. Arrhythmias
2. congestive heart failure
3. Cardiogenic shock
4. Mural thrombosis and thromboembolism
21. DIAGNOSIS-
Clinical features-
1. Pain – usually sudden,severe,crushing,and
prolonged,substerna in location, often radiating to one or
both the arm’s,neck,and back
2. Indigestion
3. Apprehension- the patient is often terrified,restless and
apprehensive , due to great fear of death
4. Shock
5. Low grade fever ( accomplished by leucocytosis and
elevated ESR
22. Serum cardiac markers-:
1. Creatinine phosphokinase( ck) – ck has three
forms :
CK-MM - derived from skeletal muscle
CK-BB - derived from brain and lungs
CK-MB - mainly from cardiac muscles and
insignificant amount from extra cardiac tissue
2. Lactic dehydrogenase
3. Cardiac specific troponins
ECG changes -:
1. ST segment elevation
2. T wave inversion
3. Appearance of wide deep Q waves
