1Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. Chapter 35...

1Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.

Chapter 35

Cardiac Disorders


Learning Objectives

• Label the major parts of the heart.• Describe the flow of blood through the heart and

coronary vessels.• Name the elements of the heart’s conduction system.• State the order in which normal impulses are conducted

through the heart.• Explain the nursing considerations for patients having

procedures to detect or evaluate cardiac disorders.


Learning Objectives

• Identify nursing implications for common therapeuticmeasures, including drug, diet, or oxygen therapy; pacemakersand cardioverters; cardiac surgery; and cardiopulmonaryresuscitation.

• Explain the pathophysiology, risk factors, signs and symptoms,complications, and treatment for selected cardiacdisorders.

• List the data to be obtained in assessing the patient witha cardiac disorder.

• Assist in developing nursing care plans for patients withcardiac disorders.


Anatomy and Physiology of the Heart


Anatomy

• Chambers• Two upper atria (right and left)• Two lower ventricles (right and left)

• Muscle layers• Endocardium, myocardium, and epicardium

• Valves• Atrioventricular valves

• Mitral and tricuspid• Semilunar valves

• Aortic and pulmonic


Heart Sounds

• The first heart sound (S1), referred to as lub, occurs when the ventricles contract during systole and when the mitral and tricuspid valves close

• The second heart sound (S2), called dub, occurs during ventricular relaxation or diastole and is caused by the closing of the aortic and pulmonic valves


Figure 35-1


Coronary Blood Flow

• Left coronary artery and the right coronary artery• Left coronary artery branches into the left anterior

descending and circumflex arteries • Right coronary artery branches to supply the

sinoatrial (SA) and the atrioventricular (AV) nodes, the RA and RV, and the inferior part of the LV


Coronary Blood Flow

• Venous system parallels the arterial system: the great cardiac vein follows the left anterior descending artery and the small cardiac vein follows right coronary artery

• Veins meet to form the coronary sinus (largest coronary vein), which returns deoxygenated blood from the myocardium to the right atrium


Figure 35-2


Figure 35-3


Conduction

• SA node, called the pacemaker, initiates the impulse • The impulse is carried throughout the atria to the AV node,

located on the floor of the RA • Impulse is delayed in the AV node, then transmitted to the

ventricles through the bundle of His • The bundle is made up of Purkinje cells and is located where the

atrial and ventricular septa meet • Bundle of His divides into left and right bundle branches • Left branch divides into anterior and posterior branches: fascicles • Terminal ends of right and left branches: the Purkinje fibers • When impulse reaches Purkinje fibers, ventricles contract


Figure 35-4


Conduction

• Cardiac innervation• Heart innervated by sympathetic and

parasympathetic fibers of the autonomic nervous system

• Sympathetic fibers distributed throughout the heart • Sympathetic stimulation results in increased heart rate,

increased speed of conduction through the AV node, and more forceful contractions

• Parasympathetic fibers (part of the vagus nerve) found primarily in the SA and AV nodes and the atrial tissue

• Parasympathetic stimulation results in slowing of heart rate, slowing of conduction through the AV node, and decreased strength of contraction


Cardiac Function

• Cardiac cycle• Contraction and relaxation of the heart make up one

heartbeat

• Cardiac output• Amount of blood (in liters) ejected per minute • Factors that affect stroke volume: preload,

contractility, and afterload

• Myocardial oxygen consumption• Myocardial tissue routinely needs 70% to 75% of

the oxygen delivered to it by the coronary arteries


Age-Related Changes

• Heart• Increased density of connective tissue and

decreased elasticity • Number of pacemaker cells in the SA node

decreases, as does the number of nerve fibers in the ventricles

• Blood vessels• The number of pacemaker cells in the SA node

decreases, as does the number of nerve fibers in the ventricles


Nursing Assessment of Cardiac Function


Chief Complaint and History of Present Illness

• Symptoms related to cardiac disorders include fatigue, edema, palpitations, dyspnea, and pain

• Note when symptoms occur, what aggravates them, and what relieves them


Medical History

• Hypertension, kidney disease, pulmonary disease, stroke, rheumatic fever, streptococcal sore throat, and scarlet fever

• Document previous cardiac disorders and hospitalizations. List recent and current medications and note allergies in appropriate records


Family History

• Assess whether immediate relatives have had hypertension, coronary artery disease (CAD), other cardiac disorders, or diabetes mellitus


Review of Systems

• Systematically assess whether the patient has experienced the following: weight gain, fatigue, dyspnea (shortness of breath), cough, orthopnea (difficulty breathing in a supine position), paroxysmal nocturnal dyspnea (sudden dyspnea during sleep), palpitations, chest pain, syncope (fainting), concentrated urine, or leg edema


Functional Assessment

• Determine how this illness has affected the patient’s ability to carry out usual activities

• Activity and rest patterns and usual diet • Ask about sources of stress and coping

strategies


Physical Examination

• Vital signs• Blood pressure, pulses, and respirations

• Skin• Heart sounds

• Heart murmurs

• Extremities


Figure 35-5


Diagnostic Tests and Procedures

• Electrocardiogram (ECG) • Ambulatory ECG (Holter monitor)• Implantable loop monitor/recorder (ILR)• Echocardiogram (heart sonogram)• Transesophageal echocardiogram (TEE) • Magnetic resonance imaging (MRI) • Multiple-gated acquisition scan


Diagnostic Tests and Procedures

• Stress test (exercise tolerance test)• Perfusion imaging• Thallium imaging• Ultrafast computed tomography• Cardiac catheterization • Electrophysiology study (EPS)


Figure 35-6


Laboratory Tests

• Arterial blood gases• Pulse oximetry• Cardiac enzymes• Creatine phosphokinase• Cardiac protein markers• Complete blood count• Lipid profile• B-type natriuretic peptide (BNP)• C-reactive protein (CRP)


Figure 35-7


Drug Therapy

• Cardiac glycosides• Antianginals• Antidysrhythmics• Angiotensin-converting enzyme (ACE)

inhibitors (ACEIs)• Diuretics• Anticoagulants


Drug Therapy

• Heparin• Low-molecular-weight heparin (LMWH)• Warfarin• Antiplatelet agents• Fibrinolytic agents (also called thrombolytics)• Lipid-lowering agents• Analgesics


Diet Therapy

• Low-fat, high-fiber diet • Well-balanced diet

• Emphasis on fruits, vegetables, grains, and proteins low in fat (fish, legumes, poultry, lean meats)

• Cholesterol intake should be limited to

200 mg/day; foods with trans fatty acids, limited to 8

• Exercise program may help achieve optimal weight


Diet Therapy

• Sodium• A diet containing sodium 2 g/day most often

prescribed

• Potassium• Patients taking potassium-wasting diuretics need

adequate potassium in the diet


Other Therapeutic Measures

• Oxygen therapy• Pacemakers

• Temporary• Permanent

• Cardioversion


Cardiac Surgery

• Common surgical procedures • Pacemaker insertion• Repair or replace valves or septa or remove tumors• Coronary artery bypass surgery


Cardiac Surgery

• Preoperative nursing care• Interventions

• Fear and Anxiety


Cardiac Surgery

• Postoperative nursing care• Interventions

• Ineffective Breathing Pattern• Pain• Ineffective Thermoregulation• Decreased Cardiac Output• Risk for Infection• Anxiety


Cardiac Disorders


Coronary Artery Disease (CAD)

• Arteriosclerosis • Abnormal thickening, hardening, loss of elasticity of arterial walls

• Atherosclerosis• Form of arteriosclerosis; inflammatory disease that begins with

endothelial injury and progresses to the complicated lesion seen in advanced stages of the disease process

• Progression of lesions• Fatty streak • Fibrous plaque• Complicated lesions

• Collateral circulation• Branches grow from existing arteries; provide increased blood flow


Coronary Artery Disease (CAD)

• Risk factors• Nonmodifiable

• Age, gender, heredity, and race

• Modifiable• Increased serum lipids, high blood pressure, cigarette

smoking (nicotine), diabetes mellitus with elevated blood glucose, obesity, sedentary lifestyle

• Other factors• Stress, sex hormones, birth control pills, excessive alcohol

intake, high homocysteine levels


Angina Pectoris

• The most common symptom of CAD• Demand for oxygen by myocardial cells exceeds

supply • Stable angina

• Occurs with exercise or activity and usually subsides with rest

• Unstable angina • Pain more severe, occurs at rest or with minimal exertion, is

often not relieved by NTG or requires more frequent NTG administration, and is not predictable

• Variant angina • Caused by coronary artery spasm; may not be associated with

CAD• Unpredictable and often occurs at rest


Angina Pectoris

• Medical treatment• Initial therapy for patients with angina

• A Aspirin and antianginal therapy• B Beta-blocker and blood pressure• C Cigarette smoking and cholesterol• D Diet and diabetes• E Education and exercise


Acute Myocardial Infarction

• Risk factors for AMI • Obesity, smoking, a high-fat diet, hypertension,

family history, male gender, diabetes mellitus, sedentary lifestyle, and excessive stress



• Pathophysiology• Begins with occlusion of a coronary artery • Over 4-6 hours, ischemia, injury, infarction develop • Ischemia results from a lack of blood and oxygen to

a portion of the heart muscle • If ischemia is not reversed, injury occurs • Deprived of blood and oxygen, the affected tissue

becomes soft and loses its normal color • Continued ischemia: infarction of myocardial tissue • Ischemia lasting 20 minutes or more is sufficient to

produce irreversible tissue damage



• Complications• Heart failure, cardiogenic shock, thromboembolism,

and ventricular aneurysm/rupture• Signs and symptoms

• Pain • Heavy or constrictive pain located below or behind sternum• May radiate to the arms, back, neck, or jaw

• Patient becomes diaphoretic and lightheaded and may experience nausea, vomiting, and dyspnea

• The skin is frequently cold and clammy • Patient experiences great anxiety; feeling of

impending doom



• Medical diagnosis• History and the physical signs and symptoms• Laboratory evidence and ECG changes

• Cardiac markers• Troponin, myoglobin, and cardiac enzymes

• Electrocardiogram • Ischemia: ST segment depressed; T wave is inverted• If there has been total occlusion of a coronary artery, the

ECG will show ST elevation (STEMI) • Following infarction, another change often seen on the ECG

waveforms is a significant Q wave


Figure 35-8



• Medical treatment• Drug therapy

• Sublingual or intravenous nitroglycerin • Morphine or Demerol• Oxygen • Fibrinolytic therapy • Aspirin and beta-adrenergic blockers

• Percutaneous coronary intervention (PCI)• Intracoronary stents• Coronary atherectomy • Laser angioplasty • Radiation therapy

• Coronary artery bypass graft surgery


Figure 35-9


Figure 35-10


Figure 35-11



• Assessment• Ask patient to describe the pain, including type,

location, duration, and severity

• Interventions• Pain• Decreased cardiac output• Anxiety

• Cardiac rehabilitation


Heart Failure

• Etiology and risk factors• Two types

• Disorders that increase the workload of the heart • Disorders that interfere with heart’s pumping ability

• Patients at risk for HF: those with CAD, AMI, cardiomyopathy, hypertension, COPD, pulmonary hypertension, anemia, disease of the heart valves, and fluid volume overload


Heart Failure

• Pathophysiology• The LV, RV, or both fail as pumps • Usually left side of heart fails first; right side fails as

a result of the left-sided failure

• Compensation• Sympathetic compensation • Renal compensation • Natriuretic peptides • Ventricular hypertrophy


Heart Failure: Signs and Symptoms

• Left-sided heart failure • Anxious, pale, and tachycardic • Consecutive blood pressure readings may show a

downward trend • Auscultation of the lung fields reveals crackles,

wheezes, dyspnea, and cough

• S3 and S4 heart sounds heard


Heart Failure: Signs and Symptoms

• Right-sided heart failure • Increased central venous pressure, jugular venous

distention, abdominal engorgement, and dependent edema

• Anorexia, nausea, and vomiting from the abdominal engorgement

• Fatigue, weight gain, decreased urinary output


Heart Failure

• Medical diagnosis• History, physical examination, radiographs, and

laboratory test results


Heart Failure

• Medical treatment• Drug therapy

• ACE inhibitors, diuretics, beta-adrenergic blockers, inotropic agents, cardiac glycosides, and nitrates. In addition, certain patients will benefit from B-type natriuretic peptide

• Intra-aortic balloon pump (IABP)• Ventricular assist devices (VADs) • Biventricular pacing • Surgery

• Coronary artery bypass grafting, valve repair or replacement, partial left ventriculectomy, and cardiac transplantation


Heart Failure

• Assessment• Heart sounds, rate, and rhythm • Jugular vein distention • Baseline respiratory assessment of rate, rhythm,

and breath sounds is vital • Measure weight and blood pressure accurately • Inspect skin and palpate for turgor and edema • Intake and output records and daily weights


Heart Failure

• Interventions• Decreased Cardiac Output• Impaired Gas Exchange• Fluid Volume Excess• Activity Intolerance• Anxiety


Infective Endocarditis

• Etiology and risk factors• Primarily affect the valves• Incidence has decreased with the use of antibiotics,

but there has been a resurgence of the problem in intravenous drug abusers

• Patients with valvular disease also at risk



• Pathophysiology• Pathogens, usually bacteria, enter the bloodstream

by any of the previously mentioned means • The pathogen accumulates on the heart valves

and/or the endocardium and forms vegetations



• Complications• Heart failure and embolization

• Signs and symptoms• Fever, chills, malaise, fatigue, and weight loss • Chest or abdominal pain; may indicate embolization • Petechiae inside the mouth and on the ankles, feet,

and antecubital areas • Osler’s nodes on the patient’s fingertips or toes



• Medical diagnosis• History, physical examination, results of lab studies • Echocardiography • Serial blood cultures; elevated WBC

• Medical treatment• Antimicrobials, rest, limitation of activities• Prophylactic anticoagulants • Surgery to replace an infected prosthetic valve



• Assessment• Review patient’s history for risk factors, recent

invasive procedures, pathologic cardiac conditions, and onset of symptoms

• Assess for temperature elevation, heart murmur, evidence of HF (cough, peripheral edema), and embolization



• Interventions• Administer prescribed antibiotics • Assess cardiac output and monitor for complications • Teach patient about the medications prescribed and

any restrictions imposed• Encourage adequate rest


Pericarditis

• Etiology and risk factors• Inflammation of the pericardium • May be primary disease or associated with another

inflammatory process • The disease may be acute or chronic

• Acute pericarditis caused by viruses, bacteria, fungi, chemotherapy, or AMI (Dressler’s syndrome)

• Chronic pericarditis caused by tuberculosis, radiation, or metastases


Pericarditis

• Pathophysiology• In acute pericarditis, inflammatory process

increases amount of pericardial fluid and inflammation of the pericardial membranes

• In chronic pericarditis, scarring of the pericardium fuses the visceral and parietal pericardia together

• Loss of elasticity results from the scarring • Constrictive process prevents adequate ventricular

filling


Pericarditis

• Complications• Pericardial effusion or accumulation of fluid in the

pericardial space • May lead to cardiac tamponade

• Signs and symptoms• Chest pain

• Most severe on inspiration • Sharp and stabbing but may be described as dull or

burning • Relieved by sitting up and leaning forward

• Dyspnea, chills, and fever


Pericarditis

• Medical diagnosis• Serial ECGs • Echocardiogram • CPK-MB • Blood cultures

• Medical treatment• Analgesics, antipyretics, anti-inflammatory agents,

and antibiotics • Surgical creation of a pericardial window for chronic

pericarditis with effusion


Pericarditis

• Assessment• Assessment of heart sounds especially important

• Interventions• Rest and reduction of activity • Administer and teach patient about medications • Emotional support • Vital signs; auscultate for pericardial friction rub • Note pain characteristics and response to

analgesics and anti-inflammatory agents • Monitor the ECG for dysrhythmias


Cardiomyopathy

• Disease of the heart muscle • Cause often unknown; may be secondary to another

disease process • Usually leads to heart failure • Three types: dilated, hypertrophic, and restrictive• Risk factors with dilated CMP are excessive use of

alcohol, pregnancy, and infections • Hypertrophic CMP: common in younger individuals• Amyloidosis, sarcoidosis, and other

immunosuppressive disorders may predispose individuals to restrictive cardiomyopathy


Figure 35-12


Cardiomyopathy

• Pathophysiology• Dilated cardiomyopathy: dilation of the ventricle and

severely impaired systolic function• Hypertrophic cardiomyopathy: LV hypertrophies and

there is thickening of the ventricular septum• Restrictive cardiomyopathy: the myocardium

becomes rigid and noncompliant


Cardiomyopathy

• Signs and symptoms• Dilated cardiomyopathy: dyspnea, fatigue, left-sided

heart failure, and moderate-to-severe cardiomegaly • Hypertrophic cardiomyopathy: dyspnea, orthopnea,

angina, fatigue, syncope, palpitations, ankle edema, and S4 sounds

• Restrictive cardiomyopathy: dyspnea, fatigue, right-sided HF, S3 and S4 sounds, and mitral valve regurgitation


Cardiomyopathy

• Medical diagnosis • Echocardiography • Chest radiography


Cardiomyopathy

• Medical treatment• Dilated cardiomyopathy: positive inotropic drugs,

diuretics, ACE inhibitors and vasodilators; heart transplant

• Hypertrophic cardiomyopathy: antidysrhythmics, antibiotics, anticoagulants, calcium channel blockers, beta-blockers; surgical interventions; implantable cardioverter-defibrillator

• Restrictive cardiomyopathy: similar to that of HF therapy. Heart transplantation may be considered


Cardiomyopathy

• Assessment• Primarily for heart failure • Be alert for dyspnea, cough, edema, dysrhythmias,

and decreased cardiac output

• Interventions• Similar to that of patients with HF • A hopeful atmosphere and careful explanation of

care requirements • Encourage the family to support the patient • Guide the patient to make lifestyle changes • Encourage patient to make decisions and choices


Figure 35-13


Sudden Cardiac Death

• When heart activity and respirations cease abruptly • Most common reason is coronary heart disease • Often preceded by ventricular tachycardia or

ventricular fibrillation and occasionally by severe bradydysrhythmias

• Sudden cardiac death may be the first indication of CAD

• Other causes: left ventricular dysfunction, cardiomyopathy, hypokalemia, antidysrhythmics, liquid protein diets, and high alcohol consumption

• Those who survive sudden cardiac death need extensive testing to determine its nature and cause


Sudden Cardiac Death

• Implantable cardioverter/defibrillator • For patients with life-threatening recurrent

ventricular fibrillation who are unresponsive to medications or pacemakers

• The device senses heart rate, diagnoses rhythm changes, and treats ventricular dysrhythmias


Nursing Care

• Promote psychosocial adaptation • Body image change and a fear of shocks

• Patients and families need teaching and support

• Family instructed in CPR • ID bracelet and a card with instructions about

the ICD setting carried at all times • Advise to avoid strong magnetic fields


Valvular Disease

• Mitral stenosis: narrowing of the opening in the mitral valve that impedes blood flow from the LA into the LV

• Mitral regurgitation: allows blood to flow back into the LA during diastole

• Mitral valve prolapse: one or both leaflets enlarges and protrudes into the LA during systole

• Aortic stenosis: valve cusps become fibrotic and calcify • Aortic regurgitation: fibrosis and thickening of the aortic

cusps progress until the valve no longer maintains unidirectional blood flow


Cardiac Transplantation

• The first heart transplantation was performed in 1967 in South Africa by Dr. Christiaan Barnard

• Today in the United States, approximately 2500 are done annually for end-stage heart disease

• Donor must meet the criteria for brain death, have no malignancies outside the central nervous system, be free of infection, and not have experienced severe chest trauma



• Donor and recipient organs carefully matched • Recipient must be free of infection at the time

of transplantation • Patient prepped as any open-heart procedure • Cardiopulmonary bypass initiated; recipient’s heart

is removed except for the posterior portions of the atria

• Donor heart trimmed and anastomosed to the remaining native heart

• Patient removed from bypass, heart restarted, and chest is closed



• Aftercare similar to that of coronary artery bypass surgery • Hemodynamic monitoring, ventilation, cardiac

assessment, care of chest tubes, and accurate intake and output measurements are vital

• Modified protective isolation used • Patients and families taught sign/symptoms of

infection, to avoid crowds and others with infections

• Lifelong immunosuppression• Rejection monitored by endomyocardial

biopsies


Electrocardiogram Monitoring

• 12-lead electrocardiogram• Looks at heart from 12 directions or perspectives • Permits more precise evaluation of the heart’s

electrical activity

• Continuous ECG monitoring • Most units that perform continuous monitoring use

the five-lead system with four limb electrodes and a chest electrode


Figure 35-15



• Interpretation of electrocardiograms• Heart’s electrical activity represented by deflections,

positive and negative, from the baseline • P wave, QRS complex, and T wave

• Criteria for interpreting electrocardiograms• Rate calculation• Rhythm • P waves• PR interval • QRS complex• T waves• QT interval



• Interpretation of electrocardiograms• Normal sinus rhythm

• The most common cardiac rhythm is sinus in origin because the impulse originates in the SA node; is conducted normally

• Common dysrhythmias (rhythm disturbance from problem in the conduction system)

• Atrial dysrhythmias • Junctional or escape rhythms • Ventricular dysrhythmias


Figure 35-17


Figure 35-18


Figure 35-19


Figure 35-20


Figure 35-21


Figure 35-22


Figure 35-23


Figure 35-24


Figure 35-25


Figure 35-26


Figure 35-27


Figure 35-28


Figure 35-29


Figure 35-30


Hemodynamic Monitoring

• Central venous catheter• Placed through the skin, into a venous access

(brachial, femoral, subclavian, or jugular sites), and threaded into the RA

• Catheter may have 1 to 3 lumens • Mixed venous oxygen saturation



• Pulmonary artery catheter• Swan-Ganz catheter• Longer than the central venous catheter • Inserted like the central venous catheter and is

threaded through the RA, tricuspid valve, RV, pulmonic valve, and into pulmonary artery

• Cardiac output• Measured continuously or by thermodilution



• Arterial line• Provides a direct measurement of systolic and

diastolic blood pressures

1Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. Chapter 35...

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