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NUR 212 Cardiac Disorders 2025 BS
Cardiac Disorders Overview
Definition and Significance of Cardiac Disorders
Cardiac disorders refer to a range of conditions affecting the heart's ability to function properly. These disorders are significant because they are a leading cause of morbidity and mortality worldwide, impacting the quality of life for millions, and necessitating comprehensive healthcare resources to manage and treat.
Anatomy of the Heart
Key Structures of the Heart:
Right Pulmonary Arteries: Carry deoxygenated blood from the right ventricle to the lungs.
Superior Vena Cava: Transports deoxygenated blood from the upper body to the right atrium.
Aorta: The largest artery in the body, carries oxygenated blood from the left ventricle to the systemic circulation.
Right Atrium: Receives deoxygenated blood; plays a crucial role in blood flow management.
Pulmonary Semilunar Valve: Prevents backflow into the right ventricle during diastole.
Left Pulmonary Arteries: Deliver deoxygenated blood to the lungs for oxygenation.
Left Atrium: Receives oxygenated blood from the pulmonary veins, essential for proper oxygenation of blood.
Cusp of Left AV (Bicuspid) Valve: Controls blood flow between the left atrium and ventricle.
Chordae Tendineae: Fibrous cords that connect the AV valves to the papillary muscles, preventing valves from inverting.
Cusp of Right AV (Tricuspid) Valve: Ensures unidirectional blood flow from right atrium to right ventricle.
Right Ventricle: The muscular chamber that pumps deoxygenated blood to the lungs.
Inferior Vena Cava: Carries deoxygenated blood from the lower body back to the heart.
Papillary Muscles: Contract to provide tension on chordae tendineae, crucial for valve function.
Left Ventricle: The strongest heart chamber, it pumps oxygenated blood to the entire body.
Descending Aorta: Supplies blood to the lower regions of the body.
Coronary Arteries: Supply blood to the heart muscle, critical for heart health.
Main Coronary Arteries:
Right Coronary Artery: Supplies the right side of the heart and parts of the left ventricle.
Left Anterior Descending Coronary Artery (LAD): Supplies the front and bottom of the left ventricle and the front of the septum.
Circumflex Coronary Artery: Supplies blood to the left atrium and the side and back of the left ventricle.
Left Main Coronary Artery: Bifurcates into the LAD and circumflex arteries, crucial for heart perfusion.
Physiology of Blood Flow
Circulation Process:
Deoxygenated blood enters the right atrium from the superior and inferior vena cava.
Blood moves through the tricuspid valve into the right ventricle.
The right ventricle pumps blood through the pulmonic valve to the lungs for reoxygenation.
Oxygenated blood returns to the left atrium, flows through the mitral valve into the left ventricle.
The left ventricle pumps oxygenated blood through the aortic valve into the systemic circulation.
Cardiac Electrical Conduction System
Components Include:
Sinoatrial (SA) Node: The heart's natural pacemaker that initiates electrical impulses.
Atrioventricular (AV) Node: Delays impulses before passing them to the ventricles, ensuring coordinate contractions.
Bundle of His: Transmits impulses from the AV node to the ventricles.
Bundle Branches (Left & Right): Conduct electrical impulses to the left and right ventricles.
Purkinje Fibers: Spread electrical impulses throughout the ventricles for coordinated contraction.
Hypertension (HTN) Overview
Prevalence:
Affects approximately 45% of adults in the United States.
71% of these individuals do not have controlled blood pressure levels.
Associated with severe health risks such as myocardial infarction (MI), heart failure, stroke, and renal disease.
Management:
Imposes the need for lifestyle modifications such as diet, exercise, and weight management, alongside pharmacological interventions.
Collaboration with organizations like the American Heart Association (AHA) and** American College of Cardiology (ACC)** for setting target management goals is essential.
Social Determinants of Health
Disparities in Hypertension Prevalence:
Blacks: Exhibit a higher prevalence of hypertension, earlier onset, greater resistance to treatment, and increased risk of end-organ damage.
Hispanics: Often show lower rates of awareness and treatment for hypertension compared to other demographics.
Blood Pressure (BP) Regulation
Normal Regulation of BP:
Involves mechanisms that control cardiac output (CO) and systemic vascular resistance (SVR).
Factors Influencing BP:
Cardiac Factors: Heart rate, contractility, and conductive properties of cardiac tissue.
Nervous System Factors: Sympathetic nervous system stimulation leads to vasoconstriction and increases cardiac output, while parasympathetic stimulation causes vasodilation.
Local Regulation: Factors such as nitric oxide act as vasodilators while endothelin serves as a vasoconstrictor.
Long-term Regulation
Renal and hormonal mechanisms such as the renin-angiotensin-aldosterone system (RAAS) play a pivotal role in maintaining fluid volume and systemic pressure.
Coronary Artery Disease (CAD) Overview
Definition:
The most prevalent form of cardiovascular disease, CAD can lead to chronic stable angina or acute coronary syndrome (ACS), including unstable angina and myocardial infarction.
Perfusion Dependency:
Proper myocardial perfusion hinges on the heart's ability to maintain adequate cardiac output.
Pathophysiology of Atherosclerosis
Etiology:
Begins with endothelial injury leading to lipid accumulation within the arterial walls, resulting in plaque formation.
Lesion Development:
Fatty streaks can progress into complex lesions requiring aggressive management strategies to mitigate plaque growth.
Collateral Circulation:
May develop to compensate for obstructions, providing alternative routes of blood flow to nourish the myocardium.
Risk Factors for CAD
Non-Modifiable Risk Factors:
Age: Risk increases with age.
Gender: Men typically have a higher risk.
Ethnicity: Certain ethnic groups are at increased risk.
Family History: A familial predisposition to heart disease exists.
Modifiable Risk Factors:
High serum lipids: Elevated cholesterol levels.
Hypertension: Increases workload on the heart.
Tobacco Use: Damages blood vessels and contributes to atherosclerosis.
Diabetes: Metabolic condition that significantly raises cardiovascular risk.
Obesity: Associated with higher rates of hypertension and diabetes.
Sedentary Lifestyle: Lack of physical activity contributes to numerous cardiovascular risk factors.
Interprofessional and Nursing Care for CAD
Goals:
To identify high-risk patients and implement strategies to manage and mitigate their risks effectively.
Lifestyle Changes:
Encouraging healthful diet adjustments and increased physical activity can significantly lower CAD risk.
Medication Management:
Implementation of statins for cholesterol management is critical for reducing CAD risk along with antihypertensive and antidiabetic medications as needed.
Nutrition and Lifestyle Interventions
Recommendations:
Focus on heart-healthy diets rich in fruits, vegetables, whole grains, and lean proteins, while reducing saturated fats and cholesterol intake. Increasing physical activity levels is also paramount for reducing CAD risk effectively.
Patient Education
Importance:
Patient education enhances understanding of disease processes, facilitates medication adherence, and encourages positive lifestyle changes critical for effective risk management.
Chronic Stable Angina
Characteristics:
Intermittent chest pain linked to myocardial ischemia, often triggered by exertion and relieved by rest.
Management Strategies:
Acute Care:
Position patient comfortably, provide supplemental oxygen, and monitor vital signs closely.
Long-term Management:
Advocate for regular physical activity, implementation of effective stress management techniques, and adherence to medications.
Diagnosis of Acute Coronary Syndrome (ACS)
Unstable Angina: Chest pain at rest or with minimal exertion, indicating suboptimal blood flow to the heart without evidence of myocardial infarction.
ST-Elevation Myocardial Infarction (STEMI): Characterized by prolonged ischemia that results in myocardial cell death, identifiable by elevated ST segments on an ECG and elevated cardiac biomarkers.
Non-ST-Elevation Myocardial Infarction (NSTEMI): Similar to STEMI, but without the classic ST elevation on the ECG; coronary artery blockage is present, confirmed by elevated cardiac biomarkers.
Definition:
A term encompassing a range of conditions resulting from insufficient blood flow to the heart muscle, including unstable angina and myocardial infarction.
Management:
May necessitate urgent intervention techniques such as
Percutaneous Coronary Intervention (PCI)
Definition: PCI is a non-surgical procedure used to treat narrowing (stenosis) or blockages in the coronary arteries that supply blood to the heart muscle. It is also known as coronary angioplasty.
Procedure Overview:
Preparation: Patients are typically administered local anesthesia and may receive sedatives to keep them comfortable during the procedure.
Access Site: The catheter is usually inserted through the femoral artery in the groin or the radial artery in the wrist.
Catheter Insertion: A thin, flexible tube (catheter) is guided through the blood vessels to the site of the blockage using fluoroscopy (live X-ray).
Dilation: Once positioned, a small balloon at the tip of the catheter is inflated to expand the narrowed artery, which restores blood flow.
Stenting: Following balloon inflation, a stent (a small mesh tube) may be placed in the artery to keep it open and reduce the risk of future blockages. Stents can be bare metal or drug-eluting, the latter of which releases medication to help prevent restenosis (re-narrowing).
Completion: After the stent is in place, the catheter is removed, and pressure is applied to the insertion site to prevent bleeding.
Indications for PCI:
Significant coronary artery disease (CAD) where lifestyle modifications or medications alone haven't improved symptoms.
Acute coronary syndromes (ACS), including unstable angina or ST-elevation myocardial infarction (STEMI), where rapid restoration of blood flow is critical.
Benefits:
Minimally Invasive: PCI is less invasive than open-heart surgery, resulting in shorter recovery times, reduced pain, and less hospital stay.
Rapid Symptom Relief: Patients often experience immediate relief of chest pain and other symptoms following the procedure.
Lower Mortality Rates: PCI is associated with reduced mortality in patients with significant coronary artery blockages compared to those treated with medication alone.
Risks and Complications: While PCI is generally safe, potential risks include:
Bleeding or bruising at the catheter insertion site.
Allergic reactions to contrast dye used for imaging.
Blood vessel damage or closure.
Risk of acute myocardial infarction (MI) or need for emergency bypass surgery if complications arise.
Post-Procedure Care:
Patients are monitored for several hours for any signs of complications and are advised to maintain a heart-healthy lifestyle post-procedure.
Medications such as antiplatelet agents (e.g., aspirin, clopidogrel) may be prescribed to prevent stent thrombosis and improve long-term outcomes.
Conclusion: PCI is a valuable intervention for patients with symptomatic or life-threatening coronary artery disease. Regular follow-up with healthcare providers is essential to manage risk factors and improve overall cardiac health.
(PCI) or thrombolytic therapy, dictated by patient presentation and severity.
Diagnostic Studies:
Utilize tools such as electrocardiography (ECG), cardiac biomarkers, and coronary angiography to assess the presence and severity of coronary blockages.
Nursing Management Goals:
Focus on ensuring pain relief, monitoring for possible complications, and providing emotional support throughout hospitalization.
Sudden Cardiac Death (SCD)
Definition:
Refers to unexpected death arising from cardiac causes, frequently associated with coronary artery disease.
Risk Factors:
Include previous myocardial infarction, history of dysrhythmias, and existing structural heart disease, necessitating careful monitoring in high-risk populations.
Conclusion
Key Takeaways:
Continuous education, proactive management strategies, and lifestyle modifications are essential for patients at risk of cardiac disorders, emphasizing the importance of early detection and intervention to optimize health outcomes.
