Copyright © 2008 Lippincott Williams & Wilkins. Chapter 26 Assessment of Cardiovascular Function

Copyright © 2008 Lippincott Williams & Wilkins. Overview of Anatomy and Physiology of the Heart Three layers of the heart: –Endocardium –Myocardium –Epicardium Four chambers Heart valves Coronary arteries Cardiac conduction system Cardiac hemodynamics

Copyright © 2008 Lippincott Williams & Wilkins. Structure of the Heart

Copyright © 2008 Lippincott Williams & Wilkins. Coronary Arteries

Copyright © 2008 Lippincott Williams & Wilkins. Cardiac Conduction System

Copyright © 2008 Lippincott Williams & Wilkins. Terms: Cardiac Action Potential Depolarization: electrical activation of a cell caused by the influx of sodium into the cell while potassium exits the cell Repolarization: return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits Refractory periods: –Effective refractory period: phase in which cells are incapable of depolarizing –Relative refractory period: phase in which cells require a stronger-than-normal stimulus to depolarize

Copyright © 2008 Lippincott Williams & Wilkins. Cardiac Action Potential

Copyright © 2008 Lippincott Williams & Wilkins. Great Vessel and Heart Chamber Pressures

Copyright © 2008 Lippincott Williams & Wilkins. Terms: Cardiac Output Stroke volume: the amount of blood ejected with each heartbeat Cardiac output: amount of blood pumped by the ventricle in liters per minute Preload: degree of stretch of the cardiac muscle fibers at the end of diastole Contractility: ability of the cardiac muscle to shorten in response to an electrical impulse Afterload: the resistance to ejection of blood from the ventricle Ejection fraction: the percent of end-diastolic volume ejected with each heartbeat

Copyright © 2008 Lippincott Williams & Wilkins. CO= SV x HR Control of heart rate –Autonomic nervous system and baroreceptors Control of strike volume –Preload: Frank-Starling law –Afterload: affected by systemic vascular resistance and pulmonary vascular resistance –Contractility increased by catecholamines, SNS, some medications and decreased by hypoxemia, acidosis, some medications

Copyright © 2008 Lippincott Williams & Wilkins. Assessment Health history –Demographic information –Family/genetic history –Cultural/social factors Risk factors See Chart 26-2 –Modifiable –Nonmodifiable

Copyright © 2008 Lippincott Williams & Wilkins. Most Common Clinical Manifestations Chest pain Dyspnea Peripheral edema and weight gain Fatigue Dizziness, syncope, changes in level of consciousness

Copyright © 2008 Lippincott Williams & Wilkins. Assessing Chest Pain

Copyright © 2008 Lippincott Williams & Wilkins. Assessment Nutrition Elimination Activity and exercise Sleep and rest Cognition and perception Self-perception and self-concept Roles and relationships Sex and reproduction Coping and stress

Copyright © 2008 Lippincott Williams & Wilkins. Health Promotion, Perception, and Management Questions Ask regarding health promotion and preventive practices. What type of health issues do you have? Are you able to identify any family history or behaviors that put you at risk for this health problem? What are your risk factors for heart disease? What do you do to stay healthy? How is your health? Have you noticed any changes? Do you have a cardiologist or primary health care provider? How often do you go for check-ups? Do you use tobacco or alcohol? What medications do you take?

Copyright © 2008 Lippincott Williams & Wilkins. Laboratory Tests Cardiac biomarkers CK and CK-MB Myoglobin Troponin T and I Lipid profile Brain (B-type) natriuretic peptide C-reactive protein Homocysteine

Copyright © 2008 Lippincott Williams & Wilkins. Electrocardiography 12-lead ECG Continuous monitoring: hardwire and telemetry Signal-averaged ECG Continuous ambulatory monitoring Transtelephonic monitoring Wireless mobile monitoring Cardiac stress testing –Exercise stress testing –Pharmacologic stress testing

Copyright © 2008 Lippincott Williams & Wilkins. Diagnostic Tests Chest x-ray and fluoroscopy Echocardiogram and transesophageal echocardiogram Radionuclide imaging Myocardial perfusion imaging Equilibrium radionuclide angiocardiography (ERNA or MUGA) CT scans PET scans Electrophysiologic testing (EPS)

Copyright © 2008 Lippincott Williams & Wilkins. Cardiac Catheterization Invasive procedure used to measure cardiac chamber pressures and assess patency of the coronary arteries Requires ECG and hemodynamic monitoring; emergency equipment must be available Assessment prior to test; allergies, blood work Assessment of patient after procedure: circulation, potential for bleeding, potential for dysrhythmias Activity restrictions Patient education before & after procedure See Chart 26-4

Copyright © 2008 Lippincott Williams & Wilkins. Hemodynamic Monitoring CVP Pulmonary artery pressure Intra-arterial BP monitoring

Copyright © 2008 Lippincott Williams & Wilkins. Phlebostatic Level

Copyright © 2008 Lippincott Williams & Wilkins. Pulmonary Artery Catheter

Copyright © 2008 Lippincott Williams & Wilkins. Pulmonary Artery Catheter and Pressure Monitoring System

Copyright © 2008 Lippincott Williams & Wilkins. Arterial Pressure Monitoring System