3.2 INFECTIOUS DISEASES OF THE HEART

• 3.2.1.ENDOCARDITIS

• 3.2.2. MYOCARDITIS

• 3.2.3. PERICARDITIS

•Endocardium → Endocarditis•Myocardium → Myocarditis•Pericardium → Pericarditis

The Layers of the HeartEndocardium – membrane that lines inside the chambers of the heart and forms the surface of the valves.

Myocardium – muscular tissue of the heart

Pericardium – membrane enclosing the heart.

3.2.1. Endocarditis

• It is an inflammation of the inner layer of the Heart, the ENDOCARDIUM.• It usually involves the HEART VALVES.• Characterized by a lesion called

VEGETATION

Other structures which may be involved include the:• INTERVENTRICULAR SEPTUM • CHORDAE TENDINAE• MURAL ENDOCARDIUM• INTRACARDIAC DEVICES.

How does Endocarditis happen?This occurs when bacteria or other germs from another part of your body, such as your mouth, spread through your bloodstream and attach to damaged areas in your heart

Symptoms:• Fever and chills • A new or changed heart murmur• Fatigue• Aching joints and muscles• Night sweats• SOB

• Paleness• Persistent cough• Swelling on the

feet, legs and abdomen

• Unexplained weight loss

• Blood in the urine• Tenderness in the

spleen• Osler’s nodes• petechiae

Risk factors:• Artificial heart valves• Congenital heart defects• History of endocarditis• Damaged heart valves• History of intravenous (IV) illegal drug use

Complications:

• Stroke • Organ damage• Infections in other parts of the body• Heart failure

Tests and diagnosis• Blood tests• Transesophageal echocardiogram• Electrocardiogram• Chest X-ray• CT scan or MRI

Treatment:

• Antibiotics – first line of treatment in Endocarditis

• Surgery – If the infection damages your heart valves

– Sometimes needed to treat Endocarditis caused by a fungal infection.

Prevention:

Dental health

Avoid body piercings and tattoos.

Seek prompt medical attention if you develop any type of skin infection, open cuts or sores that don’t heal properly.

Preventive antibiotics

• Artificial or prosthetic heart valve• Previous endocarditis infection• Certain types of congenital heart defects• Heart transplant complicated by heart

valve problems

Antibiotics are recommended before the ff procedures:a)Dental procedures that cut through the

gum tissue or part of the teethb)Procedures involving the respiratory tract,

infected skin or tissue that connects muscle to bone

3.2.2. Myocarditis

• Inflammation of the middle layer of the heart wall, the MYOCARDIUM.

• It involves the heart’s MUSCLE CELLS and ELECTRICAL SYSTEM.• May be chronic or acute• It is usually of sudden onset.• Studies suggest that myocarditis is a major cause of sudden (20%),

unexpected death in adults less than 40 years of age

COMPARISON:

Myocarditis causes the heart muscle to become thick and swollenIf severe, the pumping action of the heart weakens, and the heart won’t be able to supply the rest of the body with enough blood.CLOTS could also form, leading to a stroke or a heart attack.

An infectio

us organis

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Triggers an

autoimmune ,

cellular or

humoral reaction

Local and

systemic

immunological inflamm

ation ensues

Inflammation leads to

hypertrophy, fibrosis and

inflammatory changes of

the myocardium

and conduction

system

Heart muscle weakens and

contractility is reduce

d

Heart muscl

es dilate

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Pinpoint

hemorrhages

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Pathophysiology of Myocarditis

EtiologyInfection:  • viruses : Cocksackie B, Echovirus, HIV, Adenovirus,

Cytomegalovirus, Epstein-Barr Virus, Varicella Zoster Virus and others  

• bacteria: Diptheria (in ¼ of Diptheria cases), in setting of endocarditis

• spirochetes: lyme (Borrelia bergdorferi) • fungi: Candida, Aspergillus, histo, cocci, crypto • parasites: Chagas (Trypanosoma cruzi), toxocara,

trichinosis

EtiologyDrugs/Toxins • hypersensitivity reactions: sulfa, PCN, NSAIDs, • chemo: doxorubicin • others: cocaine, Li, cyclophosphamide, EtOH Autoimmune diseases:•  SLE (Systemic Lupus Erythematosus), sarcoidosis, RA,

dermatomyositis • Other: radiation, Giant-Cell myocarditis

Clinical ManifestationPatients may be asymptomatic with an infection that resolves on its own. May develop mild to moderate symptoms such as:• Flu-like symptoms and tachycardia (most common)• Dyspnea• Palpitations• discomfort in chest and upper abdomen

Clinical Manifestation• Pericardial friction rub may be heard if associated with

pericarditis• Cardiomegaly (arrhythmia, edema)• pulsus alternans may be present (alternating strong and weak

pulses)• Murmurs of mitral or tricuspid regurgitation are common, s3

and s4 gallops may also be heard.• CHF symptoms may develop

Medical Management• Penicillin - for hemolytic streptococci• ACE Inhibitors - relax the blood vessels in the heart and help

blood flow more easily• Beta-blockers are avoided because it decreases the strength

of ventricular contraction (have a negative inotropic effect)• Anticongestive measures such as diuretics, inotropics,

oxygen, digoxin (use cautiously) IVIG (2g/kg over 24 hours) effective in some cases secondary to Kawasaki disease;

Nursing Management • Monitor for Digitalis toxicity (Dysrhythmia, anorexia, N/V, bradycardia,

headache, malaise)• Apply and instruct patient and family in use of elastic stockings and

active and passive exercises• Instruct patient to increase physical activity slowly and report symptoms

of rapid heart rate upon increasing activity.• Instruct patient to avoid competitive sports and alcohol• Promote bed rest• Continuous cardiac monitoring

Diagnostic Tests• ECG: Sinus tachycardia, decreased QRS voltage, ST-T wave

abnormalities, arrhythmias• CXR: Enlarged heart; pulmonary edema• 2D Echo: Cardiac chamber enlargement, impaired LV function• Labs: Cardiac troponin levels (Troponin-I and T) and

myocardial enzymes (CK-MB) elevated; confirmed by biopsy

Prevention:• Avoid people with viral or flu-like illnesses until they’ve

fully recovered.• Follow good hygiene.• Avoid risky behaviors.• Minimize exposure to ticks.• Get your vaccines, especially those that protect against

rubella and influenza – diseases that can cause Myocarditis.

Key points in Myocarditis• Myocarditis can be caused by viral, bacterial, spirochetal,

fungal, or parasitic infections, drugs/toxins, and autoimmune diseases. • EKG’s in myocarditis can have non-specific ST-T changes,

atrial or ventricular arrhythmias, or ST-elevation diffusely or focally. • Troponin I will be positive in 1/3 of cases of myocarditis. • Treatment is supportive, including exercise avoidance

3.2.3 Pericarditis• It is the swelling and irritation of the membranous sac

enveloping your heart called the PERICARDIUM. • May be ACUTE or CHRONIC.• Associated with a sharp chest pain (pericardium rub• Usually begins suddenly but doesn’t last long.

Acute pericard

ial effusion

The pressure

of the pericard

ial cavity

increases

FV (filling

volume) of the

ventricular

diastoledecreas

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SV (Strok

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ses

BP lowe

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Pathophysiology of Pericarditis

Etiology• Idiopathic/Viral: 75-80% of cases Infection:  • viral: coxsackie, echo, adeno, EBV, HIV, hepatitis B • bacterial: Staph, Strep, pneumococcus, H. flu, TB • fungal: histo (most common fungus), aspergillus, cocci • rickettsial, parasitic

Etiology• Radiation • Malignancy: lung, breast, lymphoma, melanoma, primary

cardiac (rhabdomyosarcoma) • Autoimmune: SLE, RA, systemic sclerosis, vasculitis, Behcet’s,

sarcoid • Drugs/toxins: procainamide, INH, hydralazine (lupus

syndrome), PCN, dilantin • Other: uremia, post-MI, post-CABG, trauma, amyloid

Clinical Manifestation/Physical Exam• Chest pain is the most common complaint

• sharp, pleuritic, retrosternal, radiating to L shoulder, relieved by sitting up

• can mimic angina/ischemic chest pain

• Can have fever, myalgias, fatigue • Heart failure is rare and indicates myocarditis •  Pericardial friction rub can be heard in up to 85% of

patients • scratchy or squeaking sound • classic 3 phase: atrial systole, ventricular systole, ventricular

diastole

• Look for evidence of Tamponade on exam

Types of acute pericarditis:

• Serous pericarditis• Fibrinous pericarditis• Purulent pericarditis• Hemorrhagic pericarditis

Serous pericarditis• Usually caused by non-infectious inflammatory diseases such

as RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS, SCRELORDERMA, TUMOR, UREMIA.

• BACTERIAL PLEURITIS may cause sufficient irritation of the pericardium.

• VIRAL INFECTION antedates pericarditis.• Morphology: inflammatory reaction with few neutrophils,

lymphocytes and histiocytes.

Fibrinous pericarditis• Most common type of pericarditis• It is an exudative inflammation.• The epicardium is infiltrated by the fibrinous exudate.• Common causes include: ACUTE MYOCARDIAL

INFARCTION, POSTINFARCTION (incl. Dressler syndrome), UREMIA, RADIATION and TRAUMA.

Purulent or suppurative pericarditis• Red, granular surface coated with pus, lots of subsurface

neutrophils, up to 500ml exudate in the pericardium.• Immunosuppression facilitates this condition.• Commonly seen in patients with empyema, mediastinitis,

endocarditis, burn, and post pericardiodectomy.• Diagnosis: ECG, echocardiography, Gallium67 scan with

SPECT, Gallium67 and TC99 scan.

Hemorrhagic pericarditis• Blood mixed with a fibrinous or suppurative effusion• Most commonly caused by TUBERCULOSIS or DIRECT

NEOPLASTIC INVASION.• Can also occur in severe bacterial infections• Also common after surgery and may cause tamponade• Clinical significance is similar to suppurative pericarditis

Type of chronic pericarditis:

• Adhesive mediastino pericarditis• Constricitive pericarditis

Adhesive mediastino pericarditis• Follows suppurative pericarditis, cardiac surgery or

irradiation. • The pericardial potential space is obliterated• Adhesion of the external surface to the surrounding

structures occurs• Clinically, systolic contraction of ribcage and

diaphragm may be observed• ↑ workload may cause massive cardiac hypertrophy

and dilatation

Constrictive pericarditis

• Usually caused by hemorhhagic, suppurative or caseous pericarditis

• Heart becomes encased in a layer of scar or calcification

• Usually 0.5cm to 1cm thick, resembling a plaster mold

Clinical Management• Treatment depends on the cause• Analgesics and NSAIDS• Corticosteroid• Antibiotic• Pericariocentesis• Surgical treatment

Nursing Management• Stress the importance of bed rest,• Assist the patient with bathing if necessary.• Provide a bedside commode because this method puts

less stress on the heart rather than using a bed pan.• Place the patient in upright position to relieve

dyspnea and chest pain.• Provide analgesics to relieve pain and oxygen to

prevent tissue hypoxia.

Nursing Management• Assess the patient’s cardiovascular status frequently,

watching for signs of cardiac tamponade.• Monitor the patient’s pain level and the effectiveness of

analgesics.• Explain all tests and treatments to the patient.• Before giving antibiotics, obtain a patient history for

allergy.• Tell the patient to resume his daily activities slowly and

to schedule rest periods into his daily routine for a while.

Diagnostic Tests• Labs/EKG/ECHO • Troponin I positive in up to 49% of patients •  EKG shows diffuse ST elevations and PR depression • Look for PR elevation in lead aVR (“knuckle sign”) • Can be followed by diffuse T-wave inversions • No Q waves or reciprocal ST-changes (unlike acute MI) • Echo typically shows small accumulation of fluid w/o tamponade

and nl LV fxn

Key Points • Acute pericarditis is most commonly

viral/idiopathic but can be caused by infection, radiation, malignancy, autoimmune disease, drugs, and uremia.• Classic presentation is pleuritic chest pain w/

associated friction rub. • EKG shows diffuse ST elevation and PR

depression w/ PR elevation in lead aVR.

Rosemarie C. ReyesBSN III

NCM 103 – LectureMr. Rafael Salinas