ENDOCARDITIS

ENDOCARDITIS

Endocarditis is inflammation of the inside lining of the heart chambers and heart valves (endocardium). 

RHEUMATIC ENDOCARDITIS

Acute rheumatic fever follows group A beta-hemolytic streptococcal pharyngitis and is said to be auto immune (because it is caused by streptococcal protein produced by the organism which resemble proteins produced by the heart valve – myosin and M-protein) which initiates anti bodies reaction that form the .

Causative agent:

Although the bacteria are the causative agents, malnutrition, overcrowding, and lower socioeconomic status may predispose individuals to rheumatic fever. In most cases, people with rheumatic fever develop various degrees of rheumatic heart disease associated with valvular insufficiency, heart failure, and death. The disease also affects all bony joints, producing polyarthritis.

Pathophysiology

The heart damage and the joint lesions of rheumatic endocarditis are not infectious in the sense that these tissues are not invaded and directly damaged by destructive organisms; rather, they represent a sensitivity phenomenon or reaction occurring in response to hemolytic streptococci. Leukocytes accumulate in the affected tissues and form nodules, which eventually are replaced by scar tissue.

The myocardium is certain to be involved in this inflammatory process; rheumatic myocarditis develops, which temporarily weakens the contractile power of the heart. The pericardium also is affected, and rheumatic pericarditis occurs during the acute illness. These myocardial and pericardial complications usually occur without serious sequelae. Rheumatic endocarditis, however, results in permanent and often crippling side effects. It affects majorly the mitral valve, followed by aortic valve, pulmonic valve and pulmonic valve.

Clinical Manifestations

v Shortness of breath

v Crackles

v Wheezing sound in the lungs

v Tiny translucent vegetations or growths, which resemble pinhead-sized beads arranged in a row along the free margins of the valve flaps.

v Valvular regurgitation

v Valvular stenosis

v Stenoticvalvular orifice

v Dysrhythmias

v Pneumonia

v Heart failure

Usually, the myocardium can compensate for these valvular defects very well for a time. As long as the myocardium can compensate, the patient remains in apparently good health. With continued valvular alterations, the myocardium is unable to compensate thereby presenting symptoms of heart failure.

Complications

v Pancarditis (inflammation of the three layers of the heart)

v Pulmonary abscesses

v Hematuria

v Renal failure

v Myocardial infarction

v Stroke

Prevention

Rheumatic endocarditis is prevented through early and adequate treatment of streptococcal infections. A first-line approach in preventing initial attacks of rheumatic endocarditis is to recognize streptococcal infections, treat them adequately, and control epidemics in the community. Every nurse should be familiar with the signs and symptoms of streptococcal pharyngitis.

Medical Management

The objectives of medical management are to eradicate the causative organism and prevent additional complications, such as a thromboembolic event. Long-term antibiotic therapy is the recommended treatment, and penicillin administered parenterally remains the medication of choice.

Nursing Management

Teach patient about the disease, its treatment, and the preventive steps needed to avoid potential complications

INFECTIVE ENDOCARDITIS

Infective endocarditis is an infection of the valves and endothelial surface of the heart. Endocarditis usually develops in people with cardiac structural defects (e.g. valve disorders). Infective endocarditis is more common in older people, probably because of decreased immunologic response to infection and the metabolic alterations associated with aging.

Causes:

The cause is idiopathic but any Invasive procedures, particularly those involving mucosal surfaces, can cause a bacteremia. If a person has some anatomic cardiac defect, bacteremia can cause bacterial (infective) endocarditis.

High risk group

People at higher risk for infective endocarditis are those with:

v Prosthetic heart valves

v History of endocarditis

v Complex cyanotic congenital malformations

v Systemic or pulmonary shunts

v Conduits that were surgically constructed (e.g. saphenous vein grafts, internal mammary artery grafts).

v Rheumatic heart disease

v Mitral valve prolapse

Pathophysiology

Infective endocarditis is most often caused by direct invasion of the endocardium by a microbe (e.g. streptococci, enterococci, pneumococci, staphylococci, fungi and rickettsia). The infection usually causes deformity of the valve leaflets, but it may affect other cardiac structures such as the chordae tendineae.

Clinical Manifestations

Usually, the onset of infective endocarditis is insidious.

v Headache

v Vague complaints of malaise

v Anorexia, weight loss, cough,

v Back and joint pain

v Splinter hemorrhages (i.e. reddish-brown lines and streaks)

v Petechiae may appear in the conjunctiva and mucous membranes

v Small, painful nodules (Osler’s nodes) may be present in the pads of fingers or toes.

v Hemorrhages with pale centers (Roth’s spots) that may be seen in the fundi of the eyes are caused by emboli in the nerve fiber layer of the eye

v Heart murmurs (systolic and diastolic)

v Temporary or transient cerebral ischemia

v strokes

Diagnostic Findings

Blood culture: A definitive diagnosis is made when a microorganism is found in two separate blood cultures, in vegetation, or in an abscess.

Echocardiogram may assist in the diagnosis by demonstrating a moving mass on the valve, prosthetic valve, or supporting structures and by identification of vegetation, abscesses, new prosthetic valve dehiscence, or new regurgitation. An echocardiogram may also demonstrate the development of heart failure.

Prevention

Although rare, bacterial endocarditis may be life-threatening. Antibiotic prophylaxis is recommended for high risk patients immediately before and sometimes after the following procedures:

v Dental procedures that induce gingival or mucosal bleeding, including professional cleaning and placement of orthodontic bands (not brackets)

v Tonsillectomy or adenoidectomy

v Surgical procedures that involve intestinal or respiratory mucosa

v Bronchoscopy with a rigid bronchoscope

v Esophageal dilation

v Gallbladder surgery

v Cystoscopy

v Urethral dilation

v Urethral catheterization if urinary tract infection is present

v Urinary tract surgery if urinary tract infection is present

v Prostatic surgery

v Incision and drainage of infected tissue

v Vaginal hysterectomy

All catheters should be removed as soon as they are no longer needed or no longer function.

Complications

v Stroke

v Heart failure

v Valvular stenosis or regurgitation

v Mycotic (fungal) aneurysms

Medical Management

The objective of treatment is to eradicate the invading organism through adequate doses of an appropriate antimicrobial agent.

Pharmacologic Therapy

Antibiotic therapy is usually administered parenterally in a continuous intravenous infusion

v Penicillin is usually the medication of choice.

v Antifungal agent, such as amphotericin B (Abelect, Amphocin, Fungizone).

Surgical Management

After the patient recovers from the infectious process, seriously damaged valves may need to be replaced.

v Surgical valve replacement greatly improves the prognosis for patients with severe symptoms from damaged heart valves.

v Aortic or mitral valve excision and replacement are required for patients who develop congestive heart failure despite adequate medical treatment.

v Prosthetic valve endocarditis (i.e. infected prostheses) requires valve replacement.

Nursing Management

v Monitors body temperature

v Assess heart sounds

v Monitor for signs and symptoms of systemic embolization

v Monitor for signs and symptoms of pulmonary infarction and infiltrates.

v Assesses signs and symptoms of organ damage such as stroke (ie, cerebrovascular accident or brain attack).

v Direct patient care toward management of infection.

v Instruct the patient and family about the need for prophylactic antibiotics before, and possibly after, surgical procedures.

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