How to Prevent Cardiac Complications from Infective Endocarditis

• Infective endocarditis is an inflammatory process that involves the heart’s inner lining. 
• Left untreated, infective endocarditis can cause many cardiac complications. 
• Recognizing the signs of infective endocarditis and making a diagnosis can help prevent those complications.

Have you ever wondered if a previous infection could cause another infection for your patient? Have you ever told your patients with valvular disorders how important it is to maintain oral hygiene? Do they know a minor dental procedure can become deadly for them in the long run?

These are questions to consider, especially if you treat patients with valvular disorder, IV drug abuse, or who have prosthetic valves. It’s essential to cure and prevent infections, as they can lead to infection of the heart, known as infective endocarditis. 

What is Infective Endocarditis?

Infective endocarditis, or bacterial endocarditis, is an inflammatory process involving the heart’s inner lining — the endocardium and the valves separating the four chambers, atrium, and ventricles. Bacteria primarily cause it, and it has many manifestations and sequelae.

Without early treatment and diagnosis, infective endocarditis can lead to cardiac complications. Therefore, a thorough history and physical examination are imperative and can help in early diagnosis and timely treatment, eventually lowering death rates.   

Acute endocarditis is rapidly destructive, occurs on standard heart valves, and, if left untreated, can be fatal. Subacute endocarditis occurs in already damaged heart valves because of acquired or congenital heart disease. If left untreated, it can take up to a year to cause death.

Causes of Infective Endocarditis

The most common cause of infective endocarditis since the 1960s is nosocomial infections that occur because of IV catheters, prosthetic valve endocarditis, and IV drug abuse. The disease can occur at the intravenous site, on the catheter, on another body site, or from the intravenous fluid administered.

The most common cause of acute infective endocarditis is a bacterial infection, primarily because of streptococcal and staphylococcal infections. 

Subacute infective endocarditis can occur in people with acquired cardiac lesions. Possible entry sources for the organism include lesions, skin abscesses, and gastrointestinal or genitourinary infections. Surgical procedures can also increase the risk of infective endocarditis. 

Other factors include:

• Congenital heart diseases, such as Fallot’s tetralogy, bicuspid aortic valve, ventricular septal defect
• Parenteral drug abuse
• Rheumatic heart disease
• Prosthetic valve surgery
• Mitral valve prolapse 
• Marfan’s syndrome
• History of endocarditis
• Intravascular placement of foreign objects such as dialysis shunts, pacemakers, intravenous catheters, and hyperalimentation catheters
• Asymmetrical septal hypertrophy
• Pulmonary, skin, and bone infections 

Signs & Symptoms of Infective Endocarditis

The symptoms of subacute bacterial endocarditis (SBE) are as follows:\

• Night sweats 
• Low-grade fever (< 39° C)
• Fatigue and malaise
• Weight loss
• Chills and arthralgia
• Tachycardia 

Often, the first clue for patients with SBE is valvular insufficiency. Initially, less than 15% of patients have a fever with a murmur; however, both symptoms develop as the condition progresses. 

Renal emboli can rarely lead to flank pain and gross hematuria. Splenic emboli may cause upper quadrant pain. Clubbing of fingers and toes or splenomegaly may also occur due to prolonged infection. 

The symptoms of acute bacterial endocarditis are far more aggressive and severe, causing stroke, renal failure, septic emboli, congestive heart failure, and sepsis.   

Diagnosing Infective Endocarditis 

Blood cultures, echocardiography, other imaging procedures, and clinical criteria can help diagnose the condition. Infective endocarditis is diagnosed using a combination of clinical, echocardiographic, microbiological, and pathologic characteristics evaluated with the Duke diagnostic criteria.

The primary blood culture criteria from the Duke diagnostic criteria include:

•  Two blood cultures positive for typical organisms of endocarditis
• Blood cultures persistently positive for one of these organisms from vultures drawn more than 12 hours apart
• Three or more times separate positive cultures obtained at least one hour apart

 The primary echocardiographic criteria from the Duke diagnostic criteria include:  

• Echocardiogram positive for infective endocarditis, documented with oscillating intracardiac mass on a heart valve or supporting structures, in the path of regurgitant jets, or on implanted material without another anatomic explanation  
• Cardiac abscess  
• Development of new partial dehiscence of a prosthetic valve  
• The onset of new valvular regurgitation 

The minor Duke diagnostic criteria include:  

• A predisposing heart condition or use of intravenous drug (IVDA)  
• Fever (100.4 degrees Fahrenheit or higher)  
• Vascular phenomena that include Janeway lesions or conjunctival hemorrhage, central arterial emboli, intracranial hemorrhage, mycotic aneurysm, and septic pulmonary infarcts  
• Immunologic phenomena that include rheumatoid factor, glomerulonephritis, Roth spots, or Osler nodes  
• Positive results of blood cultures but not meeting the significant criteria or serologic evidence of active infection with the organism consistent with infective endocarditis  
• Echocardiogram results indicate infective endocarditis but do not meet the significant echocardiographic Duke criteria for infective endocarditis. 

According to the modified Duke criteria, two primary criteria, one major and three minor criteria, or five minor criteria, should be met for the definitive diagnosis of endocarditis. 

Assessment Tips for Suspect Patients with Infective Endocarditis 

Detailed History: Ask patients with pre-existing cardiac abnormalities about recent dental procedures in the past three to six months. If they had any dental procedures, then ask which procedure and if bleeding occurred after it. Often, patients with acute infective endocarditis have a continuous complaint of fever, ranging from 103F to 104F. However, the patient gets a low-grade fever from 99F to 102F in subacute bacterial endocarditis. 

Ask the patient about the presence of other symptoms such as fatigue, malaise, anorexia, night sweats, and weight loss. 

Physical Examination  

Patients with infective endocarditis appear acutely ill. Check their body temperature, dry mucus membranes, and diaphoresis. The conjunctivae, mucus membranes, and the upper extremities should be inspected for the presence of petechiae. Check their nail beds, fingers, and toes to rule out splinter hemorrhages and Osler nodes. 

In patients with infective endocarditis, splenomegaly is common, so palpate the abdomen to check for it. Lastly, auscultate the heart to know about murmurs and tachycardia. In most patients with subacute infective endocarditis, a heart murmur is present, commonly mitral and aortic regurgitation. In contrast, it is typically absent in patients with acute infective endocarditis. 

The Nurse’s Role in Treating Infective Endocarditis Patients

Most people at increased risk of infective endocarditis receive antibiotic therapy before, after, and during invasive procedures to avoid the occurrence of bacteremia. Tell them to complete the course as the physician prescribes and not to stop taking it before completion. 

The risk of endocarditis is linked with procedures that involve teeth and gum manipulation, leading to bleeding, or procedures involving the gastrointestinal or genitourinary systems. Encourage them to report bleeding with any procedure, especially if they have valvular heart disease or prosthetic valves. 

Patients who have developed congestive heart failure with infective endocarditis need supportive oxygen therapy, and management of acute renal failure with dialysis may be required. Counsel the patient for that, as it may be overwhelming for them to cope with the situation.  

Refer the patient to the appropriate rehabilitation program and addiction consultation clinic if they have developed endocarditis due to IV drug abuse. Patients who do not respond to antibiotics or those who have developed infective endocarditis in a prosthetic valve may need to get the infected valve replaced surgically.

Treatment of Infective Endocarditis

Antibiotics are given depending on the causative organism to treat infective endocarditis. The following drugs are commonly used to treat infective endocarditis:

• Penicillin G is given as 2 million units IV q hours for four weeks. It helps treat penicillin-susceptible streptococcal infections in patients with subacute bacterial endocarditis. Patients allergic to penicillin can receive vancomycin.  
• Other commonly used antibiotics are oxacillin, gentamicin, vancomycin, or tobramycin, given as 2g IV q hours, up to 5 mg/kg per day IV q 8 hours. They help treat acute bacterial endocarditis commonly caused by S.aureus and gram-negative bacilli.   
• Acetaminophen is given at 650 mg every 4 to 6 hours to treat fever, joint pain, and muscle aches. 

Discharge and Home Healthcare Guidelines 

Patients should be educated about early detection and prevention tips to prevent the occurrence of infective endocarditis. Tell them to maintain oral hygiene and encourage them to inform healthcare providers, including dentists, about their endocarditis history. Patients should also take antibiotics properly as prescribed by the physician to prevent the subsequent occurrence of endocarditis.

Ensure that patients and their caregivers understand all medications, including their dose, action, route, adverse effects, and precautions. Explain that completing the antibiotic course is imperative as stopping can lead to antibiotic resistance, making the condition even worse and difficult to treat. Educate them about the common side effects of antibiotic therapy, such as yeast infection, gastrointestinal distress, skin rash, and sun sensitivity. Encourage them to seek medical attention promptly if they encounter any side effects.

Inform them about proper IV catheter site care and signs of infiltration.

Compel your patients to take their body temperature daily at the same time and take antipyretics as directed by the physician. Patients should report any signs of heart failure and embolization along with chills, fatigue, fever, weight loss, or malaise.   

The Bottom Line

Untreated infective endocarditis can be fatal, but even with treatment, the chances of death remain high. The healthy outcome is generally poor in people who have large vegetations, an underlying disorder, aortic or multiple valve involvement, infection with the resistant organism, prosthetic valve infections, valve ring infections, large vegetations, a long delay in treatment, major embolic events, mycotic aneurysms, and polymicrobial bacteremia. 

Diagnosing and managing infective endocarditis can be a prolonged and complex process. But early involvement of a professional team can lead to safe patient care.

Most cases of infective endocarditis are treated with antibiotics alone. However, intracardiac complications or evidence of peripheral embolization, might require surgical intervention.

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