PBL 1 : CHEST PAIN pathophysiology of myocardial infarction complications of MI management of MI epidemiology of MI new guidelines for the treatment of MI.

Types of angina

Stable / Typical angina

can be relieved by rest or nitroglycerin / vasodilators

Unstable / Crescendo angina

chest pains occur with increased frequency , duration and intensityprecipated by progressively less effort symptoms are not relieved by rest or nitroglycerin - therefore require hospital admission and more aggressive therapy to prevent death and progression to myocardial infarction

Prinzmetal angina

due to coronary artery spasm

COMPLICATIONS OF MYOCARDIAL INFARCTION (MI)

Cardiac tamponade is pressure on the heart that occurs when blood or fluid builds up in the space between the heart muscle (myocardium) and the outer covering sac of the heart (pericardium).

Cardiopulmonary

sytolic/diastolic dysfunction

decreased cardiac output

(↓ stroke volume)

tachycardia

arrhythmias

dyspnea

pulmonary congestion/edema

Systemic Vasculature

↑ sytemic vascular resistance

↑ blood volume

↑ systemic edema

Neurohumoral

sympathetic activation

↑ circulating catecholamines

↑ angiotensin II and ↑ aldosterone

↑ natriuretic peptides

↑ arginine vasopressin (ADH)

PTCA - Percutaneous Transluminal Coronary Angioplasty

Drugs that can be used to treat MI

Beta blockers - reduce heart rate (negative chronotropic effect) and contractility ( negative inotropic effect ) - block β1- receptors - With β-blockers, the demand for oxygen by the myocardium is reduced both during exertion and at rest- e.g : propranolol , metoprolol

Calcium channel blockers (CCBs) - e.g : Nifedipine , verapamil , diltiazem

Thrombolytics (dissolve clot) Anti-thrombotics (prevent thrombus formation)

- anticoagulant and anti-platelet drugs Analgesics (to relieve pain)

- e.g : aspirin

Primary prevention

Quit smoking Maintain a healthy diet Regular exercise

Transthoracic echocardiogram (TTE). This is the most common type. Views of the heart are obtained by moving the transducer to different locations on your chest or abdominal wall.

Stress echocardiogram. During this test, an echocardiogram is done both before and after your heart is stressed either by having you exercise or by injecting a medicine that makes your heart beat harder and faster. A stress echocardiogram is usually done to find out if you might have decreased blood flow to your heart (coronary artery disease, or CAD).

Doppler echocardiogram. This test is used to look at how blood flows through the heart chambers, heart valves, and blood vessels. The movement of the blood reflects sound waves to a transducer. The ultrasound computer then measures the direction and speed of the blood flowing through your heart and blood vessels. Doppler measurements may be displayed in black and white or in color.

Transesophageal echocardiogram (TEE). For this test, the probe is passed down the esophagus instead of being moved over the outside of the chest wall. TEE shows clearer pictures of your heart, because the probe is located closer to the heart and because the lungs and bones of the chest wall do not block the sound waves produced by the probe. A sedative and an anesthetic applied to the throat are used to make you comfortable during this test.

Echo can be used as part of a stress test and with an electrocardiogram (EKG or ECG) to help your doctor learn more about your heart.