Endocarditis, infective endocarditis, bacterial endocarditis
What is this condition?
Inflammation of the heart lining is an infection of the endocardium, heart valves, or a valve prosthesis, resulting from bacteria or fungi.
The infection produces vegetative growths on the heart valves, the lining of a heart chamber, or the inside lining of a blood vessel that may embolize (break off and travel through the bloodstream) to the spleen, kidneys, central nervous system, and lungs.
In this disorder, fibrin and platelets aggregate on the valve tissue and engulf circulating bacteria or fungi that flourish and produce vegetations. Such vegetations may cover the valve surfaces, causing ulcers and necrosis (tissue death).
Untreated, inflammation of the heart lining is usually fatal, but with proper treatment, the recovery rate is 70%. The prognosis is poorest when the inflammation causes severe valve damage, leading to insufficiency and heart failure, or when it involves a prosthetic valve.
What causes it?
Most cases of inflammation of the heart lining occur in intravenous drug abusers, people with prosthetic heart valves, and those with mitral valve prolapse. Other predisposing conditions include rheumatic heart disease, coarctation of the aorta, tetralogy of Fallor, subaortic and aortic stenosis, ventricular septal defects, pulmonic stenosis, Marfan syndrome, and degenerative heart disease, especially calcific aortic stenosis. However, some people with an inflamed heart lining have no underlying heart disease.
What arethe Symptoms of Endocarditis?
Early symptoms include malaise, weakness, fatigue, weight loss, loss of appetite, joint pain, sweating during the night, chills, valvular insufficiency and, in 90% of cases, an intermittent fever that may recur for weeks. When examining the person with a stethoscope, the doctor may hear a loud heart murmur.
In about 30% of people with the disorder, embolization (release of material into the bloodstream) from vegetating lesions or diseased valve tissue may produce:
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pain in the left upper area of the stomach, radiating to the left shoulder
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blood or pus in the urine, flank pain, and decreased urine output
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partial paralysis, inability to speak, or other nervous system deficits
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chest pain, shortness of breath, and a cough that may produce blood
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numbness and tingling in an arm, leg, finger, or toe.
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Other signs may include an enlarged spleen, skin rash, and splinter hemorrhages under the nails.
How is it diagnosed?
Three or more blood cultures in a 24- to 48-hour period identify the causative organism in up to 90% of people. The remaining 10% may have negative blood cultures, possibly suggesting fungal infection or infections that are hard to diagnose, such as Haemophilus parainfluenzae.
Echocardiography (an ultrasound test of the heart) may identify valvular damage; an electrocardiogram may show atrial fibrillation and other irregular heart rhythms that accompany valvular disease.
How is it treated?
Treatment tries to kill the infecting organism. Antibiotics should start promptly and continue for 4 to 6 weeks.
Supportive treatment includes bed rest, aspirin for fever and aches, and sufficient fluids. Severe valve damage may require corrective surgery if heart failure develops or in cases requiring that an infected prosthetic valve be replaced.
What is this condition?
This disorder involves focal or diffuse inflammation of the cardiac muscle (myocardium). It may be acute or chronic and can occur at any age. Frequently, this disease fails to cause specific cardiovascular symptoms or electrocardiogram abnormalities, and recovery is usually spontaneous, without residual defects. Occasionally, its complicated by heart failure.
What causes it?
Inflammation of the heart muscle is caused by:
- viral injections, such as coxsackievirus A and B strains and, possibly, polio, influenza, measles, German measles, adenoviruses, and echoviruses (most common causes in the United States)
- bacterial injections, such as diphtheria, tuberculosis, typhoid fever, tetanus, and staphylococcal, pneumococcal, and gonococcal infections
- hypersensitive immune reactions, such as acute rheumatic fever and postcardiotomy syndrome
- radiation therapy from large doses of radiation to the chest in treating lung or breast cancer
- chemical poisons, as in chronic alcoholism
- parasitic injections, especially South American trypanosomlasis (Chagas disease) in infants and immunosuppressed adults, and toxoplasmosis
- injections caused by parasitic worms, such as trichinosis.
What are its symptoms?
Inflammation of the heart muscle usually causes nonspecific symptoms (such as fatigue, shortness of breath, palpitations, and fever) that reflect the accompanying infection. Occasionally, it may cause mild, continuous pressure or soreness in the chest.
How is it diagnosed?
The persons history commonly reveals recent febrile upper respiratory tract infection, viral pharyngitis, or tonsillitis. A physical exam detects irregular heart rhythms, abnormal heart sounds, and possibly a murmur.
An electrocardiogram typically shows abnormalities in heart rhythm. Stool and throat cultures may identifY bacteria.
How is Myocarditis Treated?
Myocarditis treatment includes antibiotics for bacterial infection, modified bed rest to decrease the hearts workload, and careful management of complications.
Heart failure requires restricted physical activiry to minimize myocardial oxygen consumption, supplemental oxygen therapy, restricted salt intake, diuretics to decrease fluid retention, and Lanoxin to increase myocardial contractility. However, Lanoxin must be used cautiously because some people with inflammation of the heart muscle may be sensitive to even small doses.
Irregular heart rhythms require prompt but cautious administration of antiarrhythmic drugs, such as Cardioquin or Pronestyl.
