Adult Care Nursing I: Cardiovascular Assessment

Adult Care Nursing I / Theory 2024-2025 Lectures 12-14

• Unit 6, Chapter 25: Assessment of Cardiovascular Function
• Objectives include describing the relationship between anatomy and physiology of the cardiovascular system, and discussing indications, patient preparation, nursing implications for common tests & procedures used to assess & diagnose cardiovascular disease.

Anatomy of the Heart

• Structures like superior vena cava, right pulmonary artery, interatrial septum, pulmonary veins, pulmonic valve, right atrium, tricuspid valve, inferior vena cava, right ventricle, aortic arch, left pulmonary artery, descending aorta, pulmonary veins, left atrium, aortic valve, mitral valve, left ventricle, chordae tendinae, papillary muscle, interventricular septum, endocardium, myocardium, epicardium, visceral pericardium, parietal pericardium, and pericardial space are key anatomical components.
• Diagrams illustrate the flow of oxygenated and deoxygenated blood.

Cardiac Conduction System: Electrophysiology

• The SA node (60-100), AV node (40-60), right bundle branch (20-40), left bundle branch (20-40), and Purkinje fibers are part of the system, which create electrical impulses to control the heartbeat.
• Diagrams illustrate the locations and connections of these components.

Pulmonary and Systemic Circulation

• Diagrams illustrate the flow of blood through the pulmonary and systemic circuits, including the heart, arteries, veins, and capillaries.
• Key vessels and structures (e.g., anterior vena cava, pulmonary artery, capillaries of the right lung, pulmonary vein, right atrium, right ventricle, posterior vena cava, aorta, capillaries of the left lung, pulmonary vein, left atrium, left ventricle, and capillaries of abdominal organs and hind limbs) are highlighted.

Cardiac Hemodynamics

• Stroke volume (SV): The amount of blood ejected with each heartbeat (60-130 mL at rest).
• Preload: The degree of stretch of cardiac muscle fibers at the end of diastole (EDV).
• Afterload: The resistance to ejection of blood from the ventricle.
• Ejection fraction: The percentage of end-diastolic volume ejected with each heartbeat (55%-65% for the left ventricle).
• Cardiac output (CO): The amount of blood pumped by the ventricle per minute (about 4 to 6 L/min at rest).
  • CO = SV × HR (L/min).

Assessment

• Health history: Includes family history, medications, nutrition, elimination, activity/exercise, sleep/rest, self-perception/self-concept, roles/relationships.
• Physical examination: Includes heart inspection, palpation, auscultation, vital signs, sexuality/reproduction, coping/stress tolerance, and prevention strategies.
• Risk factors: Modifiable and nonmodifiable risks.

Diagnostic Evaluation

• Laboratory tests: Include lipid profile, brain natriuretic peptide (BNP), C-reactive protein, homocysteine (atherosclerosis), blood chemistry, hematology, coagulation, & proteins.
• Cardiac biomarkers include creatine kinase (CK), CK isoenzymes (CK-MB), myoglobin, troponin T and I (indicative of cardiac damage).

Electrocardiography

• Techniques: 12-lead ECG, 15-lead ECG, 18-lead ECG, continuous monitoring (hardwire, telemetry, Holter monitor), cardiac event recorders, and cardiac implantable electronic devices (e.g., mobile cardiac telemetry).
• Cardiac Stress Testing: Pt walks on treadmill to measure heart response to added stress on heart (exercise stress test) or pharmacologic agents to mimic exercise.
• Echocardiography (noninvasive ultrasound): Used to measure ejection fraction and examine cardiac structures (e.g., valves, ventricular walls).
• Transthoracic or Transesophageal testing techniques.
• Radionuclide imaging (e.g., myocardial perfusion imaging, SPECT, PET): Used to assess ventricular function & wall motion.
• Additional imaging: Includes computed tomography (CT) scan and magnetic resonance angiography (MRA).

Cardiac Catheterization

• Invasive procedure for diagnosing structural & functional heart & great vessel diseases.
• Used to measure cardiac chamber pressures and assess coronary artery patency.
• Includes Right Heart Cath (evaluates right ventricle, tricuspid and pulmonary valves, pulmonary artery pressure, oxygen saturations), Left Heart Cath (evaluates aortic arch, major branches, coronary artery patency, mitral and aortic valves).

Nursing Interventions-Cardiac Cath

• Assessment: Health history, allergies, blood work, prior to and after the procedure. Post-procedure steps: Assess cath site for bleeding, hematoma and peripheral pulses, evaluate temp, color, and cap refill of the affected extremity, screen for dysrhythmias, impose activity restrictions, and monitor for complications including contrast-induced nephropathy.

Unit 6, Chapter 26: Management of Patients With Dysrhythmias & Conduction Problems

• Normal Electrical Conduction includes structures such as SA node, AV node, Bundle of His, and right & left bundle branches, Purkinje fibers. Depolarization (electrical stimulation) = Systole, and Repolarization (electrical relaxation) = Diastole

• Properties of cardiac muscle fibers include Autorhythmicity (ability to initiate a heart beat), Excitability (respond to strength on stimulus), Conductivity and Contractility.

• The Electrocardiogram (ECG) reflects the electrical activity of the heart, electrode placement and adhesion are key for interpreting the ECG.

• Types of ECG include 12, 15 or 18 lead ECG, Hardware monitoring, telemetry and Holter monitor. Components of an ECG include, P wave, QRS complex, T wave, U wave, PR interval, ST segment, QT interval, TP interval, and PP interval, and 12-Lead ECG placement diagrams.

• Measurements of components from the ECG include time and rate and amplitude. Time and rate measurements are on the horizontal axis and the amplitude is on the vertical axises. Deflection is positive when moved upward and negative when moved downwards on the paper.

• Diagrams of P wave and QRS complex, QRS complex, T wave and U wave.

Dysrhythmias

• Disorders in heart's electrical impulses, including rate or rhythm.
• Can have life-threatening consequences and affect rate, rhythm, or both.
• May alter blood flow, causing hemodynamic changes (decrease cardiac output & blood pressure).
• Diagnosed by analyzing ECG waveform interpretations (i.e. normal rhythms or abnormal rhythms)

Consequences of Dysrhythmias

• Interfere with the heart’s pumping ability.
• Bradycardic rhythms (impacts blood flow)
• Tachycardic rhythms (shortened diastolic filling time)
• Atrial dysrhythmias reduce cardiac output.
• Ventricular dysrhythmias dramatically reduce diastolic filling leading to low cardiac output, absence of pulse, and hypotension

Etiology (causes) of Dysrhythmias

• Hypoxia, Shock, Poisoning, Drug ingestion, Myocardial Infarction(MI), Congestive Heart Failure (CHF)
• Pulmonary disorders, Electrolyte imbalances (e.g. hypokalemia), Metabolic imbalances
• Mechanisms associated with Atrial Fibrillation (AF) include atrial scar, atrial stretch/hypertrophy, mitral stenosis/regurgitation, arterial stenosis/regurgitation, myocardial degeration, advanced age, tachycardia, etc)
• Manifestations (symptoms) of dysrhythmias include irregular rate/rhythm, palpitations, chest/neck/shoulder/arm pain, dizziness, dyspnea, extreme restlessness, decreased level of consciousness, weakness, fatigue, numbness of arms/legs, cold skin, nausea, and vomiting, decreased BP, and low oxygen saturation.
• Normal Sinus Rhythm (NSR): Normal electrical impulses, with ventricular & atrial rate of 60-100 beats/min, regular rhythm, normal QRS shape & duration less than 0.12 sec, consistent shape of P-wave, before QRS, consistent PR interval (0.12-0.20 seconds), and P:QRS ratio of 1:1.
• Types/causes of Sinus Node Dysrhythmias, Atrial Dysrhythmias, Junctional Dysrhythmias, and Ventricular Dysrhythmias are given.
• Examples of some types of dysrhythmias include sinus bradycardia, sinus tachycardia, and sinus arrhythmia, atrial flutter, atrial fibrillation (AF), premature atrial complexes (PACS), junctional dysrhythmias and ventricular tachycardia (VT), ventricular fibrillation (VF), and Ventricular asystole.

Nursing Process: Dysrhythmia Assessment

• Causes, contributing factors
• Assessment of cardiac output and oxygenation
• Review of prior occurrences & possible causes of the dysrhythmia
• Psychosocial assessment: (patient's perception) of dysrhythmia
• Physical Assessment: vital signs, signs of fluid retention (jugular venous distension, lung auscultation), signs of decreased cardiac output (altered LOC), heart sounds, blood pressure/pulse pressure.

Nursing Diagnoses

• Decreased cardiac output related to inadequate ventricular filling or altered heart rate
• Anxiety related to fear of the unknown outcome of altered health state
• Deficient knowledge about the dysrhythmia and its treatment

Collaborative Problems/Potential Complications

• Cardiac arrest
• Heart Failure (HF)
• Thromboembolic event (especially with AF)

Nursing Interventions

• Monitor and manage the dysrhythmia, minimize anxiety, promote home & community-based care, educate the patient about self-care and continuing care
• Assessments include assessing vital signs, light-headedness, dizziness, fainting, 12-lead ECG, continuous monitoring, rhythm strips periodically.
• Minimize anxiety: Stay with patient, maintain safety and security, discuss emotional response, help patient develop a system for identifying contributing factors, maximize patient control.
• Educate the patient on treatment options, therapeutic medication levels, pulse monitoring before medication administration, recognizing symptoms, measures to decrease recurrence, and plans of action for emergencies (CPR).
• Address adjunctive modalities (Pacemakers, Cardioversion, Defibrillation), and their medical management. These are used when medication alone is not effective
• Patient safety measures during cardioversion/defibrillation (e.g., good contact, conductive medium pressure, synchronizer).