Causes, incidence, and risk factors

Endocarditis can involve the heart muscle, heart valves, or lining of the heart. Most people who develop endocarditis have have some abnormality of a heart valve.

Risk factors for developing endocarditis include:

• Injection drug use

• Permanent central venous access lines

• Prior valve surgery

• Recent dental surgery

• Weakened valves

Bacterial infection is the most common source of endocarditis. However, it can also be caused by fungi. In some cases, no cause can be identified.

Symptoms

• Abnormal urine color

• Chills (common)

• Excessive sweating (common)

• Fatigue

• Fever (common)

• Joint pain

• Muscle aches and pains

• Night sweats

• Nail abnormalities (splinter hemorrhages under the nails)

• Paleness

• Red, painless skin spots on the palms and soles (Janeway lesions)

• Red, painful nodes in the pads of the fingers and toes (Osler's nodes)

• Shortness of breath with activity

• Swelling of feet, legs, abdomen

• Weakness

• Weight loss

Note: Endocarditis symptoms can develop slowly (subacute) or suddenly (acute).

Signs and tests

Doctors might suspect endocarditis in people with a history of:

• Congenital heart disease

• Intravenous drug use

• Recent dental work

• Rheumatic fever

The health care provider may detect a new heart murmur, or a change in a previous heart murmur. Examination of the nails may show splinter hemorrhages.

An eye exam may show bleeding in the retina a central area of clearing. This is known as Roth's spots. There may be small, pinpoint hemorrhages (petechiae) in the conjunctiva. The fingertips may be enlarged, and the nails may appear curved. This is called clubbing.

Tests:

• Blood culture

• Complete blood count (CBC)

• Chest x-ray

• C-reactive protein (CRP)

• Echocardiogram

• ECG

• Erythrocyte sedimentation rate (ESR)

• Serology

• Transesophageal echocardiogram

Treatment

People with this condition will often need to be hospitalized at first to receive antibiotics through a vein (intravenously). Long-term antibiotic therapy is needed to get the bacteria out of the heart chambers and valves.

Patients will usually have therapy for 4-6 weeks. The antibiotic must be specific for the organism causing the condition. This is determined by the blood culture and the sensitivity tests.

Surgery to replace the heart valve is usually needed when:

• The infection is breaking off in little pieces, resulting in a series of strokes

• The person develops heart failure as a result of damaged heart valves

• There is evidence of organ damage

Expectations (prognosis)

Early treatment of endocarditis improves the chances of a good outcome. However, valve destruction or strokes can result in death.

Complications

• Arrhythmias such as atrial fibrillation

• Blood clots or an infected clot that travels other organs, causing infection and severe damage

• Brain abscess

• Brain or nervous system changes

• Congestive heart failure

• Glomerulonephritis

• Jaundice

• Severe heart valve damage

• Stroke

Calling your health care provider

Call your health care provider if you notice the following symptoms during or after treatment:

• Blood in urine

• Chest pain

• Fatigue

• Fever

• Numbness

• Weakness

• Weight loss without change in diet

Prevention

The American Heart Association recommends preventive antibiotics for people at risk for infectious endocarditis before:

• Certain dental procedures

• Surgeries on respiratory tract or infected skin, skin structures, or musculoskeletal tissue

Antibiotics are more likely to be recommended those with the following risk factors:

• Artificial heart valves

• Certain congenital heart defects, both before or possibly after repair

• History of infective endocarditis

• Valve problems after a heart transplant

Continued medical follow-up is recommended for people with a previous history of infectious endocarditis.

Persons who use intravenous drugs should seek treatment for addiction. If this is not possible, use a new needle for each injection, avoid sharing any injection-related paraphernalia, and use alcohol pads before injecting to reduce risk.