Ischemic Heart Diseases IHD Ahmad Osailan

Introduction What is IHD? Is a condition that affects the blood supply (coronary arteries of the heart) Another name for it : Coronary artery disease (CAD) Results when there is an imbalance between myocardial oxygen supply and demand due to partial blockage of the artery.

Brief Physiology of the heart the layer that consist the Muscles of the Heart = Myocardium What Helps the Blood to travel away from the Heart to organs?

Brief Physiology of the heart Now the heart in order to pump, Myocardium has to contract. Myocardium requires action potential to contract and energy metabolism. Action potential and energy metabolism require presence of O2 and nutrients within blood in coronary arteries. If there is decrease in O2 and nutrients, does the heart will function normally?

Normal coronary artery

Causes and risk factors for IHD The most underlying causes are: Atheroscelerosis: thickening and hardening of the artery wall. Plaque: (the build-up of lipid/cholesterol) in the artery wall forms as a response to injury to the endothelium in the artery wall. Therefore, causes the lumen of the artery to be narrow, which result in less oxygenated blood supply to the area after the narrowing

So, any narrowing or obstruction of the coronary arteries lead to Ischemic heart disease

Risk Factors for IHD Age: (non-modifiable risk factor) Male > 45 years Female > 55 years or premature menopause without estrogen replacement therapy Family History of premature disease (non- modifiable risk factor) Male first-degree relative <55 years Female first-degree relative < 65 years)

Risk Factors for IHD Hypertension (Modifiable Risk factor( Appears to weaken the artery wall at points of high pressure leading to injury and invasion of cholesterol. Cigarette Smoking (modifiable Risk factor) #1 cause of preventable death in US 1 in 5 CHD deaths attributable to smoking

Diabetes (modifiable risk factor) Inactivity (modifiable Risk factor) Risk Factors for IHD Diabetes (modifiable risk factor) 50% of deaths related to DM is due to CHD Inactivity (modifiable Risk factor) Sedentary person has 2x risk for developing CHD as a person who is active

Risk Factors for IHD Abnormal Blood Lipids (modifiable Risk factor) LDL Cholesterol (low density lipoprotein) HDL Cholesterol (high density lipoprotein)

LDL (Low Density Lipoproteins) Some LDL can be oxidized and takes up by endothelial cells and macrophages in the arterial wall, which leads to the first stages of atherosclerosis.

High Density Lipoproteins (HDL) HDL-C is thought to be involved in the transport of excess cholesterol from membranes to the liver for removal from the body

Problems resulting from HD Most common problems: Angina Pictoris (stable angina) Unstable angina (Acute myocardial infarction) Heart failure.

Angina Pictoris When part of the heart receive insufficient blood supply. DEF: uncomfortable sensation in the chest or neighboring anatomic structures produced by myocardial ischemia during physical exertion or emotional stress. relieved by rest with in few minutes Temporary depression of ST segment with no permanent myocardial damage

Unstable angina ( Acute MI) Increased frequency and duration of Angina episodes, produced by less exertion or at rest = high frequency of myocardial infarction if not treated

Myocardial Infarction Death of parts or area of myocardium. Region of myocardial necrosis due to prolonged cessation of blood supply Results from acute thrombus at side of coronary atherosclerotic stenosis May be first clinical manifestation of ischemic heart disease or history of Angina Pectoris

Common signs and symptoms of IHD Pain or discomfort in the chest Nausea Dyspnea Radiating pain to Left shoulder

Electrocardiogram When ischemia results in transient horizontal or downsloping ST segments or T wave inversions which normalize after pain resolution ST elevation suggest severe transmural ischemia or coronary artery spasm which is less often

treatment

Pharmacologic Therapy Therapy is aimed in restoring balance between myocardial oxygen supply and demand Useful Agents: nitrates, beta-blockers and calcium channel blockers

Types of common cardiac revascularization surgeries Coronary artery bypass Grafting (CABG) Percuatneous Transluminal coronary Angioplastgy (PTCA) Valve replacement

PTCA

CABG

Management Goals to reduce Anginal Symptoms Prevent complications – myocardial infarction, and to prolong life No smoking, lower weight, control hypertension and diabetes Patients with CAD – LDL cholesterol should achieve lower levels (<100) Exercise and maintain active life style.