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Coronary Artery Disease and Acute Coronary Syndrome. The Heart as a Pump. The heart is a hollow muscular organ about the same size as your fist. It is a 2 sided pump, with a muscular wall called the septum separating the right and left sides. The Coronary Arteries.
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The Heart as a Pump • The heart is a hollow muscular organ about the same size as your fist. • It is a 2 sided pump, with a muscular wall called the septum separating the right and left sides
The Coronary Arteries • As a muscle the heart needs oxygen and nutrients to work • The heart muscle has its own blood supply through the coronary arteries • Women’s coronary arteries tend to be smaller
Description • Coronary Artery Disease (CAD) • A type of blood vessel disorder that is included in the general category of atherosclerosis
Description • Atherosclerosis • Can occur in any artery in the body • Atheromas (fatty deposits) • Preference for the coronary arteries
Description • Atherosclerosis • Terms to describe the disease process: • Arteriosclerotic heart disease (ASHD) • Cardiovascular heart disease (CHD) • Ischemic heart disease (IHD) • CAD
Description • Cardiovascular diseases are the major cause of death in the US and Canada • Heart attacks are still the leading cause of all cardiovascular disease deaths and deaths in general
Etiology and Pathophysiology • Atherosclerosis is the major cause of CAD • Characterized by a focal deposit of cholesterol and lipids, primarily within the intimal wall of the artery
Process of Coronary Artery Disease - Atherosclerosis • Over time ….a series of events within the artery • A fatty streak (permanent)– can start in infancy & young children • Fatty – ( lipid) deposits throughout the years • Narrowing and impaired blood flow occurs with the gradual occlusion as plaque thickens and blood clots form
Etiology and Pathophysiology • Endothelial lining altered as a result of chemical injuries • Hyperlipidemia • Hypertension
Etiology and Pathophysiology • Bacteria and/or viruses may have role in damaging endothelium by causing local inflammation • C-reactive protein (CRP) • Nonspecific marker of inflammation • Increased in many patients with CAD • Chronic exposure to CRP triggers the rupture of plaques
Etiology and Pathophysiology • Endothelial alteration • Platelets are activated • Growth factor stimulates smooth muscle proliferation • Cell proliferation entraps lipids, which calcify over time and form an irritant to the endothelium on which platelets adhere and aggregate
Etiology and Pathophysiology • Endothelial alteration • Thrombin is generated • Fibrin formation and thrombi occur
Response to Endothelial Injury Fig. 33-3
Stages of Development in Atherosclerosis Fig. 33-4
Etiology and PathophysiologyCollateral Circulation • Analogous to “detours” around atherosclerotic plaques • Occur normally in coronary circulation • But collaterals increase in the presence of chronic ischemia • When occlusion occurs slowly over a long period, there is a greater chance of adequate collateral circulation developing
Collateral Circulation Fig. 33-5
Risk Factors for Coronary Artery Disease • Risk factors can be divided: • Unmodifiable risk factors • Modifiable risk factors
Risk Factors for Coronary Artery Disease • Unmodifiable risk factors: • Age • Gender • Ethnicity • Genetic predisposition
Risk Factors for Coronary Artery Disease • Modifiable risk factors: • Elevated serum lipids • Hypertension • Smoking • Obesity • Physical inactivity • Diabetes mellitus • Stressful lifestyle
Diabetes Treatment • Prescribed Meal Plan (sit down with a Dietitian) • Home Blood Sugar monitoring • Regular exercise – at least 150 mins./wkly • ? Medications – pills or Insulin or both • Ongoing Education- Diabetes classes • Support – family and friends • Physician follow-up or Specialist referral A person with Diabetes is considered high risk like someone who has already had a heart attack!
Stress - “We do not laugh because we’re happy – we’re happy because we laugh”William James • Stress may not be the main cause of disease ……. but, managing stress helps us; • maintain health • deal with health problems. Anger, anxiety and depression are major emotions that need to be dealt with for a healthy heart “75% of all good health is under our control!”
Risk Factors for Coronary Artery Disease • Health Promotion • Identification of high-risk persons • Management of high-risk persons • Risk factor modification • Physical fitness • Health education in schools • Nutrition (weight control, ↓ fat, ↓ chol intake) • Cholesterol-lowering medications
Types of Angina • Results when the lack of oxygen supply is temporary and reversible • Types of Angina • Stable Angina • Prinzmetal Angina • Unstable Angina
Stable Angina Pectoris • Chest pain occurs intermittently over a long period with the same pattern of onset, duration, and intensity of symptoms • Can be controlled with medications on an outpatient basis • Pain usually lasts 3 to 5 minutes • Subsides when the precipitating factor is relieved • Pain at rest is unusual
Silent Ischemia • 80 % of patients with myocardial ischemia are asymptomatic (with pain or without pain the ischemia has the same prognosis)
Prinzmetal’s Angina • Occurs at rest usually d/t spasm of major coronary artery • Spasm may occur in the absence of CAD
Unstable Angina • Angina that is: • New in onset • Occurs at rest • Has a worsening pattern • Unpredictable • Considered to be an acute coronary syndrome • Associated with deterioration of a once stable atherosclerotic plaque
Clinical Manifestations Angina • Chest pain or discomfort (d/t ischemia) • A strange feeling, pressure, or ache in the chest • Constrictive, squeezing, heaving, choking, or suffocating sensation • Indigestion, burning
However… • Up to 80% of patients with myocardial ischemia are asymptomatic • Associated with diabetes mellitus and hypertension
Location of Chest Pain Fig. 33-12
Diagnostic StudiesAngina • ECG • Coronary angiography • Cardiac markers (CK MB, Troponin) • Treadmill exercise testing (stress test) • Serum lipid levels • C-reactive protein (CRP) • Nuclear imaging
Coronary Angiography • A diagnostic test using x-rays to record the passage of a contrast dye in the heart • To identify the presence, location and nature of any coronary artery disease • The heart valves and heart muscle can also be assessed
Coronary Angioplasty Video Link • http://www.healthscout.com/animation/1/38/main.html
Collaborative CareAngina • Treatment for stable angina: • oxygen demand and/or oxygen supply • Nitrate therapy • Stent placement
Collaborative CareAngina • Treatment for stable angina: • Percutaneous coronary intervention • Atherectomy • Laser angioplasty • Myocardial revascularization (CABG)
Coronary Artery Bypass Surgery • Is open heart surgery, which a bypass ( detour) is made to go around an area of blockage in a coronary artery • Bypasses are usually taken from the leg veins or an artery from the inside of the chest wall
Collaborative CareAngina • Drug Therapy • Antiplatelet aggregation therapy • Aspirin: drug of choice (for MI prevention) • First line of treatment for angina
Collaborative CareAngina • Drug Therapy • Nitrates • 1st line therapy for treatment of acute anginal symptoms • Dilation of vessels
Collaborative CareAngina • Drug Therapy • -Adrenergic blockers • Calcium channel blockers
Collaborative CareAngina • Percutaneous coronary intervention • Surgical intervention alternative • Performed with local anesthesia • Ambulatory 24 hours after the procedure
Collaborative CareAngina • Stent placement • Used to treat abrupt or threatened abrupt closure and restenosis following PCI
The Coronary Stent Procedure • A coronary stent is a small tubular wire object inserted into a coronary artery at the time of angioplasty to keep the previously narrowed artery open
Collaborative CareAngina • Atherectomy • The plaque is shaved off using a type of rotational blade • Decreases the incidence of abrupt closure as compared with PCI
Collaborative CareAngina • Laser angioplasty • Performed with a catheter containing fibers that carry laser energy • Used to precisely dissolve the blockage
Collaborative CareAngina • Myocardial revascularization (CABG) • Primary surgical treatment for CAD • Patient with CAD who has failed medical management or has advanced disease is considered a candidate
Clinical Manifestations Myocardial Infarction • Pain • Severe, immobilizing chest pain not relieved by rest, position change, or nitrate administration • The hallmark of an MI
Serum Cardiac Markers (Lewis p.817) • Creatine Kinase (creatine phosphokinase) (CK-MB) • Increased in > 90% of MI patients. • Begins to rise 4-6 hours • Peaks 24 hours • Returns to normal in 2 - 3 days • Troponin • Myocardial muscle protein released after an injury • Troponin T and Troponin I are cardiac specific indicators of an MI • Much more specific than CK-MB • Rises quickly and remains elevated for 2 weeks