MYOCARDIAL INFARCTION:

Myocardial infarction, commonly known as a heart attack, is the irreversible necrosis of heart muscle secondary to prolonged ischemia. This usually results from an imbalance in oxygen supply and demand, which is most often caused by plque ruptre with thrombus formation in a cornary vessel, resulting in an acute reduction of blood supply to a prtion of the myocardium.

RISK FACTORS:

Modifiable:

Hyperlipidemia

High blood pressure

Diabetes

Cigarette smoking

Obesity

Poor dietary habits

Lack of exercise

Type A personality

Non Modifiable :

Strong family history

Increasing age

males at all ages n females more after menopause

genetic

Male-pattern baldness

NON ATHEROSCLEROTIC causes of myocardial infarction:

Coronary occlusion secondary to vasculitis

Ventricular hypertrophy

Coronary artery emboli, secondary to cholesterol, air, or the products of sepsis

Congenital coronary anomalies

Coronary trauma

Primary coronary vasospasm variant angina

Drug use cocaine, amphetamines, ephedrine

Arteritis

Coronary anomalies, including aneurysms of coronary arteries

heavy exertion, fever, or hyperthyroidism

hypoxemia of severe anemia

Aortic dissection,

Infected cardiac valve through a patent foramen ovale (PFO)

Significant gastrointestinal bleed

SYMPTOMS OF MI:

Classical symptoms of acute myocardial infarction include sudden chest pain typically radiating to the left arm ,jaw,back, neck, shortness of breath, nausea, vomiting, palpitations, sweating, and anxiety

diaphoresis,wheezing,cough may also be present

SIGNS :

not relieved by nitrates&taking rest more duration than angina.pain is squeezing, aching, burning, or even sharp.pain is relieved by narcotics only.

TIMING:

Heart attacks can occur at any time, more heart attacks occur between 4:00 A.M. and 10:00 A.M. because of the higher blood levels of adrenaline released from the adrenal glands during the morning hours &increased serum concentrations of plasminogen activator inhibitor-1 (PAI-1). Increased adrenaline helps in rupture of cholesterol plaques

DIAGNOSIS:

most of times ecg plays the main role in ecg ST-T changes occur either elevation or depression which should be convex in shape