NR 507 - EDAPT - Week 2: Cardiovascular
Disorders Cardiovascular disorders - ANSWER Cardiovascular disorders are prevalent in primary care. Many of the disorders develop over several years, due to the risk factors to which individuals have been exposed. For each disorder covered in this unit, a discussion of risk factors will be included. For the concepts covered below, clinical application of each disease will be provided so that students can understand the importance of pathophysiology in diagnosing and treating the disease.
Prerequisite knowledge:
For this content, you should have a basic knowledge of cardiac anatomy; know the differences between the right and left sides of the heart, in terms of structure and function. You should also possess solid knowledge of the unidirectional blood flow through the heart. For example, deoxygenated blood arrives to the right side of the heart, travels to the pulmonary arteries to release CO2 and pick up oxygen. At this point, the oxygenated blood is carried from the lungs through the pulmonary veins to the left side of the heart where it eventually reaches the aorta to carry oxygenated blood out to the body organs. The cellular physiology related to cardiac contraction is another important basic concept to know, as electrolytes (sodium, potassium and calcium) play a major role in muscle contraction. Finally, the concepts of preload, afterload, and contractility are essential to understand, as all of these can be affected in some way when a person has cardiovascular disease.What is Coronary Artery Disease (CAD)? - ANSWER CAD is considered the leading cause of death in the United States (U.S.). It is the result of longstanding atherosclerosis.Atherosclerosis begins with damage to the endothelium. It is the endothelium, under normal functioning that maintains balance between the vasoconstrictive and vasodilation actions, prevents platelets from aggregating and control of the production of fibrin. When the endothelium becomes damaged, our familiar inflammatory processes occur. Macrophages 1 / 2
attach to the endothelium, setting up phagocytosis; plaque formation and vasoconstriction also occurs marking the beginning of atherosclerosis. The plaque lesions located in the vessels become enlarged which allows the plaque to progress within the enlarged vessel lumen. The plaque lesion disrupts normal blood flow and causes thrombus formation which can be triggered by cardiac risk factors such as elevated LDL, cholesterol, smoking and diabetes.So, why is this a problem?Well, the plaque takes decades to develop in the coronary arteries. With mild disease, blood flow can get through the arteries and the patient is asymptomatic. Overtime, this build up can lead to narrowing which results in decreased oxygen supply. When atherosclerosis reaches a clinically significant level, the patient will begin to experience angina. Further progression of the disease will result in acute coronary syndrome (ACS), formerly known as myocardial infarction (MI).The major risk factor for the development of CAD - ANSWER The major risk factor for the development of CAD is family history. There is a 50% higher risk for individuals to develop heart disease if they have a first degree relative (especially father) or sibling who has suffered from ACS or premature cardiac death (< age 55 years). Lifestyle also impacts risk, especially tobacco use and even secondhand smoke exposure. It is always important for the NP to stress smoking cessation with all patients who smoke tobacco, in order to decrease the patient's risk for CAD.Sedentary lifestyle will also increase one's risk for developing CAD. Physical inactivity can lead to overweight (BMI 25-29.9) or obesity (BMI 30 and above). Male gender, hypertension, Elevated total cholesterol, elevated low-density lipoprotein (LDL), and/or decreased high-density lipoprotein (HDL) are also risk factors, as well as diabetes mellitus.Myocardial ischemia - ANSWER Myocardial ischemia is the cause of his chest pain.Ischemia occurs when the heart's oxygen demand exceeds supply. For this patient, he experienced his chest pain during exercise. Ischemia occurred because of the narrowing of at least one coronary artery by atherosclerotic plaques. The result is the narrowing of the diameter of the coronary artery. This reduces oxygenated blood flow through the artery that leads to an insufficient oxygen supply to the heart. Adenosine is also released that stimulates
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