Coronary Atherosclerosis

Coronary Atherosclerosis

- Atherosclerosis is the abnormal accumulation of lipid deposits and fibrous tissue within arterial walls and lumen causing a blockage/narrowing of the coronary arteries and reduces blood flow to the myocardium. - In coronary atherosclerosis, blockages and narrowing of the coronary vessels reduce blood flow to the myocardium. - Atherosclerosis is a REPITITIOUS inflammatory response and injuries artery walls, causes alterations in the structural and biochemical properties of the arterial walls that occurs over many years, builds up due too the inflammation and irritation of the blood vessel walls.

Prevention of CAD

- Risk factors and prevention is most important as atherosclerosis is a silent disease and does not cause problems until years have passed. - Control cholesterol- cholesterol kicks off process of inflammation in our coronary arteries, important to monitor and control. Through lipid lowering medications, encouraging healthy diet and exercise, etc. ​ - Dietary measures​- diet that is low in saturated fats, high in soluble fiber, less than 200 mg of dietary cholesterol per day, patients may need help reading nutritional labels. - Physical activity​- regular, moderate physical activity increases HDL which is healthy cholesterol, goal is 150 minutes of moderate exercise per week or 75 minutes of vigorous exercise per week. - Lipid-lowering medications​ - Cessation of tobacco use​/limit alcohol use - Manage hypertension​- BP that is repeatedly exceeding 135/85, causes increased stiffness in the blood vessel walls and can increase stiffness in the intima leaving blood vessel injury over time and inflammation. Vessel changes contribute to the acceleration, aggravation of atherosclerosis and it can also lead to ventricular hypertrophy (enlarged heart muscle from having to work harder to pump blood into stiff arteries, leading to heart failure). - Control diabetes​- elevated blood glucose levels foster dyslipidemia and thrombus formation, which also promotes the development of atherosclerosis.

Pathophysiology of Atherosclerosis

- Section A depicts healthy lumen with o blockage, blood can flow freely, taking enough oxygen rich blood to the myocardium - Section B, C, D, E show the build up of plaque which is an inflammatory process as WBC's are released to try and manage the plaque build up of cholesterol and get engorged forming foam cells that contribute to the bulk. - E depicts a vessel that is mostly occluded where very limited blood supply is - Fibroid lining holds atherosclerotic plaques to the vessel wall. - due to narrow passage for blood to pass through person may experience chest pain due to the heart not receiving oxygen rich blood. - Low density lipoproteins (LDLs) adhere to receptors on the intimal wall. - Macrophages also ingest LDLs and transport them into the vessel wall, beginning the process of plaque formation.

Potential complications of Coronary atherosclerosis

- Unstable angina- chest pain that occurs at rest and is not relieved with nitrogycerin or with medications. - Heart failure​ - Myocardial ischemia - heart muscle damage from not getting enough oxygenated blood - Sudden cardiac arrest/MI Must remember that atherosclerosis is: it's repetitious inflammatory process that occurs over many years is triggered by cholesterol and it can cause some chest pain,discomfort in some other cardiovascular disease processes due to the buildup of plaque and fiber and thrombus in the coronary arteries.

Cholesterol Medications

- elevated LDL cholesterol is the bad cholesterol and is the primary risk factor, also the primary target of cholesterol lowering medications. - lipid lowering medications reduce coronary artery disease and there are many types of. them. Six types of lipid-lowering agents: each medication affects the lipid components somewhat differently​ - 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) (or statins)​ TOP CHOICE- if patient's cholesterol is not controlled with the statin they may add one of the other agents. - Patients may also not tolerate Statins as they can cause joint pain and discomfort for patients. - important to monitor kidney and liver function to make sure the body continues to clear the medication, statins are cleared through the liver, and liver enzymes may be elevated because one of the side effects is hepatotoxicity. - Nicotinic acids (niacin)​ - Fibric acids (or fibrates)​ - Bile acid sequestrants (or resins)​ - Cholesterol absorption inhibitors​ - must know these medications, how they act, why theyre prescribed, and the side effects to monitor for. - TABLE IN BOOK!!! https://www.youtube.com/watch?v=fTA5HOa87pM​

Clinical manifestations of Coronary Atherosclerosis

- most patients are asymptomatic until a major cardiac event happens (MI, heart failure, sudden cardiac death) - Symptoms and complications are related to the location (in the coronary vessels) and degree of vessel obstruction​ (atherosclerosis, thrombus). - if one of the larger vessels person is going to be more symptomatic than if its one of the smaller vessels. - if total occlusion (70% or greater in the vessel) they will be more symptomatic than people that have partial occlusions. - Most common manifestation is angina pectoris, which is chest pain related to myocardial ischemia.​ - Myocardial ischemia occurs when blood flow to the heart muscle is obstructed by a partial or complete blockage of the coronary artery by a buildup of plaque. - Other symptoms: (especially in elderly patients, diabetic patients, or female patients): epigastric distress, pain that radiates to jaw or left arm, SOB, atypical symptoms in women.​ - Major cardiac event​ - Myocardial infarction​ - Heart failure​ - Sudden cardiac death ​

12-Lead ECG (EKG)

- not many lab tests that are going to diagnose atherosclerosis/ more about risk factors and lifestyle - most physicians will do 12- lead ECG, looks at the heart in 12 different views - each lead gives us a different view of the heart, which helps figure out where the problem/blockage may be.

Coronary Artery Disease

- plaque build up in the coronary arteries. - CAD can be prevented and 3 million of deaths each year are in people younger than 60 - access to healthcare and prevention can determine outcome

Metabolic Syndrome

3 or more of the following six conditions - WE WANT HIGH LEVELS OF HDL AND LOW LEVELS OF LDL - if BP is persistently greater than 130/85 it will harden the vessels which will make them less elastic and less stretchy, makes it more likely to have inflammation/problems in our veins - proinflammatory state= high levels of C-reactive proteins which means inflammation. - High fibrinogen level/ Prothrombin state

Cardiac Assessment

Asses Risk Factors​ Ax with CAD - Circulation: High Blood pressure, Heart rate (is it regular, fast, slow, are there any extra sounds?), skin color, capillary refill, pulse oximetry ​ - Heart sounds: murmurs or bruits​ that may indicate stenosis - Juglar venous distention: - Breath sounds - Do they have clear lungs? or do they have enough of a blockage that their blood is backing up into their lungs. ​ - Swelling in legs or feet ​ that may suggest edema/HF - Chest discomfort or other associated symptoms (nausea, shortness of breath, epigastric discomfort, numbness)​- When did the symptoms start? - same cardiac assessment no matter if youre doing coronary atherosclerosis, angina pectoris, or an acute myocardial infarction.

HMG-CoA Reductase Inhibitors (Statins)

Atorvastatin (Lipitor) Simvastatin (Zocor) Therapeutic effects: ↓ Total cholesterol ↓ LDL ↑ HDL ↓ TGs - Inhibit enzyme involved in lipid synthesis (HMG-CoA) - Favorable effects on vascular endothelium, including anti-inflammatory and antithrombotic effects Considerations: - Frequently given as initial therapy for significantly elevated cholesterol and LDL levels - Myalgia and arthralgia are common adverse effects - Myopathy and possible rhabdomyolysis are potential serious effects - Monitor liver function tests - Contraindicated in liver disease - Check for drug interactions - Indication for use now includes ACS and stroke - Administer in evening

Bile Acid Sequestrants

Cholestyramine (Questran) Colestipol (Colestid) Therapeutic effects: - ↓ LDL - Slight ↑ HDL - Oxidize cholesterol into bile acids, which ↓ fat absorption Considerations - Most often used as adjunct therapy when statins alone have not been effective in controlling lipid levels Side effects include constipation, abdominal pain, GI bleeding - May decrease absorption of other drugs -Taken before meals

Cholesterol Absorption Inhibitor

Ezetimibe (Zetia) Therapeutic action ↓ LDL Inhibits absorption of cholesterol in small intestine Considerations: Better tolerated than bile acid sequestrants Used in combination with other agents, such as statins Side effects include abdominal pain, arthralgia, myalgia Contraindicated in liver disease

Fibric Acids (Fibrates)

Fenofibrate (TriCor) Gemfibrozil (Lopid) Therapeutic effects: ↑ HDL ↓ TGs ↓ Synthesis of TGs and other lipids Considerations: - Adverse effects include diarrhea, flatulence, rash, myalgia - Serious adverse effects include pancreatitis, hepatotoxicity, and rhabdomyolysis - Contraindicated in severe renal and liver disease - Use with caution in patients who are also taking statins

Omega-3-Acid Ethyl Esters

Fish oil capsules Therapeutic action: ↓ TGs Inhibit TG production in liver Considerations: May be used alone or in combination with other agents Side effects include GI distress, taste perversion, rash, and back pain

Comprehensive Metabolic Panel

Glucose​ Electrolytes and fluid balance (Sodium, Potassium, Carbon Dioxide, Calcium, Chloride)​ Kidney function (Creatinine, Blood Urea Nitrogen)​ Liver function (Albumin, Globulin, Total Protein, Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST)) - lipid panel may also be used to evaluate the lipid levels

Cholesterol Levels

Low-density lipoprotein (LDL) cholesterol​ Bad cholesterol ​ Makes up most of your body's cholesterol ​ Makes up most of your body's cholesterol ​ High-density lipoprotein (HDL) cholesterol ​ Good cholesterol​ - Absorbs cholesterol and carries back to liver where it is flushed from the body​ - we want high levels of HDL and low levels of LDL!!! Triglycerides ​ Type of fat in your blood that is used for energy ​ Total Cholesterol ​ Total amount of cholesterol in your blood based LDL, HDL, and triglyceride levels ​ - lipid panel is very helpful as we know that LDL cholesterol started the atherosclerosis process.

Risk Factors for Coronary Artery Disease

Non-modifiable- things that can not be changed - Family Hx of CAD​ - Increasing age​ - Gender​ - Race - lower socioeconomic classes/lower income countries= higher risk for cardiovascular disease. - patients that have insurance that are getting their stress tests/echoes every year are more likely to discover problems early on Vs. Patients with no healthcare that do no seek preventative services, may not discover problem until major event occurs. Modifiable- lifestyle choices that can be altered - Hyperlipidemia​ - Cigarette/tobacco use​ - Hypertension​ - Diabetes​ - Metabolic Syndrome​ - Obesity​ - Physical inactivity - all risk factors that are associated with inflammation and hardening of the vessel walls. - Preventative focus is important before a sudden cardiac event occurs.

Pathophysiology of CAD

REVIEW KAHN ACADEMY VID

coronary arteries

exhibits blood flow to the heart - right coronary artery and left coronary artery - each artery has smaller branches that come off of it. - this is how the heart receives oxygen rich blood supply and if there are blockages in one of the main coronary arteries, if higher up= more heart muscle damage. if in one of the smaller branches= less damage. - blockages in. the larger arteries tend to be full thickness myocardial infactions, those that are in the smaller branching areas would be a partial wall thickness MI (transmural thickness)