Cardiovascular Health: Comprehensive Overview
Unit Objectives
Review anatomy and physiology of cardiovascular system, age-related changes, risk factors for cardiovascular problems.
Discuss diagnostic tests related to cardiovascular system.
Identify normal ECG complexes and dysrhythmias.
Nursing assessment and management: atherosclerosis, coronary artery disease, angina pectoris, myocardial infarction, congestive heart failure, and hypertension.
Compare nursing assessment of myocardial ischemia, injury, and infarction.
Examine nursing implications of medications used to manage cardiovascular conditions.
Formulate a teaching plan and discuss legal/ethical issues, including DNR orders.
Cardiac Anatomy and Physiology
The heart is a four-chambered pump:
Composed of three layers:
Endocardium: thin inner layer.
Myocardium: muscular middle layer, responsible for cardiac contractions.
Epicardium: outer protective layer.
Surrounded by pericardium, providing protection and lubrication.
Blood Flow through the Heart:
Superior vena cava (SVC) and Inferior vena cava (IVC) pump deoxygenated blood to the right atrium.
From the right atrium, blood flows through the tricuspid valve to the right ventricle.
The right ventricle pumps blood through the pulmonary valve to the lungs.
Oxygenated blood returns via pulmonary veins to the left atrium, then through the mitral valve to the left ventricle.
Finally, the left ventricle pumps oxygen-rich blood through the aortic valve into the aorta.
Heart Valves
Four main valves:
Tricuspid valve: right atrium to right ventricle.
Mitral valve: left atrium to left ventricle.
Pulmonic valve: exits the right ventricle into the pulmonary artery.
Aortic valve: exits the left ventricle into the aorta.
Chordae tendineae: attach valves to the ventricular walls, preventing backflow during contraction.
Coronary Arteries and Blood Supply
Major Coronary Arteries:
Left Coronary Artery:
Supplies blood to the left side of the heart, divided into:
Left anterior descending artery
Left circumflex artery
Right Coronary Artery:
Supplies blood to the right side of the heart, divided into:
Right marginal artery
Posterior descending artery
Coronary sinus collects venous blood from heart muscle and drains into the right atrium.
Cardiac Conduction System
SA Node (Sinoatrial Node): Primary pacemaker of the heart, initiates the electrical impulse causing atrial depolarization.
AV Node (Atrioventricular Node): Delays the impulse before it spreads to the ventricles to allow for filling.
Bundle of His and Purkinje Fibers: Conduct impulses to ventricles, causing contraction.
Normal Electrocardiogram (ECG) Components:
P Wave: atrial depolarization.
QRS Complex: ventricular depolarization.
T Wave: ventricular repolarization.
PR Interval: time between atrial and ventricular depolarization.
QT Interval: duration of ventricular depolarization and repolarization.
Age-Related Changes in Cardiovascular Health
Aging increases risk for cardiovascular disease (CVD).
Changes include:
Thickening and stiffness of heart valves.
Decreased number of conduction cells and beta adrenergic receptors.
Arteries and veins thicken, narrowing, leading to decreased responsiveness to hormones.
Diagnostic Tests for CV Problems
Electrocardiogram (ECG): 12-lead for comprehensive cardiac electrical activity.
Echocardiogram: Visualizes heart structures and measures ejection fraction.
Cardiac Biomarkers: Troponins and CK-MB levels indicate myocardial injury.
Stress Testing: Evaluates heart's response to increased activity levels.
Cardiac Catheterization: Assesses coronary artery blockages using contrast dye.
Nursing Assessment and Management
Atherosclerosis
Pathophysiology of lipid deposits within arteries leading to narrowing and blockage.
Coronary Artery Disease (CAD)
Risk factors: age, gender, genetics, hypertension, and lifestyle factors such as smoking and obesity.
Management: lifestyle changes, risk screening, and possibly medications.
Angina Pectoris and Myocardial Infarction
Angina: chest pain due to myocardial ischemia, often triggered by exertion, relieved by rest.
Myocardial Infarction: results from complete blockage; emergency intervention needed.
Understanding Dysrhythmias
Types of Dysrhythmias:
Bradycardia: Slow heart rate (<60 bpm).
Tachycardia: Fast heart rate (>100 bpm).
Atrial Fibrillation: Irregular and often rapid heart rate.
Ventricular Tachycardia/Ventricular Fibrillation: Life-threatening conditions requiring immediate intervention.
Medications for CV Conditions
Calcium Channel Blockers: Decrease heart rate and dilate arteries.
Beta Blockers: Lower heart rate and blood pressure, blocking renin system.
ACE Inhibitors: Promote vasodilation, reduce cardiac workload.
Nitrates: Relieve chest pain by dilating blood vessels.
Anticoagulants and Antiplatelet Agents: Prevent thrombus formation and manage CAD.
Diuretics: Reduce fluid overload and lower blood pressure.
Nursing Implications and Patient Education
Monitor for and address medication side effects, ensuring adherence to therapeutic regimens.
Educate patients on lifestyle modifications, symptom recognition, and management strategies for acute episodes.
Review anatomy and physiology of the cardiovascular system, including the structure of the heart, its chambers, and major blood vessels, as well as age-related changes that affect cardiovascular function, potential risk factors such as diabetes, hypertension, and lifestyle habits that contribute to cardiovascular problems.
Discuss various diagnostic tests related to the cardiovascular system, including their indications, procedures, and interpretation of results for conditions like heart disease and arrhythmias.
Identify normal ECG complexes and dysrhythmias, understanding their clinical significance, how to interpret them, and the implications they have for patient care.
Conduct comprehensive nursing assessments and management of cardiovascular conditions including but not limited to atherosclerosis, coronary artery disease, angina pectoris, myocardial infarction, congestive heart failure, and hypertension, incorporating evidence-based practices and guidelines.
Compare the nursing assessment of myocardial ischemia, injury, and infarction to develop appropriate nursing diagnoses and interventions, considering patient history and presenting symptoms.
Examine nursing implications for medications used in the management of cardiovascular conditions, including their mechanisms of action, contraindications, potential side effects, and the importance of patient education regarding adherence.
Formulate thorough teaching plans addressing risk reduction strategies, medication adherence, and discuss legal/ethical issues in patient care, such as Do Not Resuscitate (DNR) orders and the importance of patient autonomy in treatment decisions.