What is Cardiac Abscess (Heart Infection)?
A cardiac abscess is an infected area within the heart’s muscles, inner lining, or tissues surrounding the heart’s valves. These infections can form naturally or on tissues surrounding an artificial heart valve. This can happen from either an infection spreading from another part of the body, like blood infection or sepsis, or from a pre-existing infection within the heart itself. A condition known as infective endocarditis, which is an inflammation of the inner layer of the heart, is often the main cause of a pre-existing heart infection.
The rate at which these cardiac abscesses occur is still being looked into. Still, it’s generally believed to be higher than what is currently reported in autopsies. Understanding the occurrence of cardiac abscesses is crucial because it helps predict patient outcomes and aids in planning treatment options. Most of the time, a single type of bacteria like Staphylococcus aureus or Escherichia coli causes these abscesses. However, in some cases, multiple types of bacteria might be involved.
Certain complications can arise from a cardiac abscess, such as irregular heartbeats noted on an electrocardiogram (ECG), a test that measures the electrical activity of your heart. Among patients with infective endocarditis, about 30% to 40% also have an abscess surrounding a heart valve, with the aortic valve being more susceptible than the mitral valve and the tissue ring that supports it. Particularly, these abscesses often occur near a weak area of the tissue ring close to a structure named the atrioventricular node (AV), explaining why heart blockage, a condition where the heart beats more slowly or irregularly, is a common result.
If artificial heart valves have been used in a patient, they’re at a higher risk for these abscesses. The infection often affects the tissue ring, rather than the leaflet (a heart’s valve flap), and the severity of electrical conduction disruption within the heart depends on how much the infection has spread within the heart’s internal electrical system. This is often observed in abscesses surrounding the aortic valve. The infection may also spread severely enough to press on or disintegrate the coronary arteries, potentially leading to acute coronary syndrome, a sudden reduction in blood flow to the heart. Some identified risk factors for these abscesses include aortic valve involvement and current intravenous drug use. All patients with a cardiac abscess have a higher risk for an embolism (an obstruction of a blood vessel from a blood clot or other foreign substance), increased illness, and death.
What Causes Cardiac Abscess (Heart Infection)?
Cardiac abscesses, which are pockets of pus in the heart, often occur due to an existing heart infection, such as infective endocarditis. This is an infection of the inner lining of your heart. Another cause could be bacteremia, which is the presence of bacteria in the blood. This could happen even without a known heart-related source.
Heart tissues that are susceptible after a heart attack, or in cases of artificial heart valve disease, usually alongside bacteremia, can also lead to a cardiac abscess.
Other less common reasons might include trauma or injury, penetrating wounds, severe burns, infections in the hearts of those who’ve received heart transplants, infected wound sites from chest surgery, pseudoaneurysm (a false aneurysm where blood collects outside a blood vessel, usually due to a leak or a hole), HIV, or parasitic infections.
Risk Factors and Frequency for Cardiac Abscess (Heart Infection)
Cardiac abscesses, which are uncommon in the United States, are often caused by a bacterium called Staphylococcus aureus. These abscesses typically affect the mitral valve, which is a part of the heart. According to a study in 2009, approximately 15% of patients with infective endocarditis, a type of heart infection, were found to have cardiac abscesses. When the infection affects artificial heart tissue or valves, it usually develops around the ring of the valve, penetrates the heart muscle, and may result in abscesses due to separation of the valve.
Here are the microorganisms that are usually associated with the formation of cardiac abscesses:
- Staphylococcus aureus
- Haemophilus species
- Enterococci
- Escherichia coli
- Beta-hemolytic streptococci
- Streptococcus pneumoniae
- Bacteroides species
- Parasitic organisms
- Hydatid cysts
Signs and Symptoms of Cardiac Abscess (Heart Infection)
The symptoms and physical signs of Infective Endocarditis (IE) can differ based on the severity (acute or subacute) and the location of the related infection in the heart. This condition is often associated with bacteremia, the presence of bacteria in the blood.
A patient’s personal health history can reveal various types of symptoms. Some people experience vague and often changing symptoms, which make the condition hard to diagnose. It’s possible for symptoms to be more severe and cause a toxic reaction in some cases, while others may experience less severe, lingering symptoms. Certain heart-related symptoms could also be present if the heart’s electrical signaling system, or conduction abnormality, is affected. Here are some symptoms that might be present:
- Fever, be it observed or reported by the patient
- Loss of appetite
- Muscle pain
- Headache
- Shortness of breath
- Joint pain
- Rashes
- Cough
- Chest pain
During a physical examination, there are several findings a doctor might consider. These signs are often related to IE, the most common cause of which is a bacterial infection. However, these signs are not specifically diagnostic for IE and their absence does not rule out the disease. Here are some common findings during a physical examination:
- Fever
- Signs and symptoms of heart failure, such as abnormal heart sounds, neck vein swelling, or breathing issues
- Signs and symptoms of valve insufficiency, where heart valves do not close properly, including typically unusual heart sounds related to the heart valves. This could be more common in patients with an artificial heart valve and other valve diseases.
- Specific neurological symptoms due to clots
- Back pain, linked with a certain type of bone infection
- Non-specific small red/purple spots
- Linear red-brown streaks under the nails
- Painful small lumps under the skin, particularly on the hands
- Non-painful spots on the palms or soles
- White-centred retinal haemorrhages
- An enlarged spleen
Testing for Cardiac Abscess (Heart Infection)
If your doctor suspects you might have a problem with one of the valves in your heart, they may order several tests. These could include measuring your blood and urine or taking blood cultures. Cultures are a way of analysing your blood under a microscope to look for disease. The blood and urine tests help check the overall health of your body.
Another test you might have is an echocardiography. There are two types – a transthoracic and a transesophageal (TEE). The TEE is typically the preferred choice as it’s more sensitive and provides a more detailed picture. It’s specifically recommended if your doctor thinks you might have a disease affecting your heart valves.
Continuous electrocardiographic monitoring might be used to check your heart’s electrical activity. If the results show a new change in your heart’s rhythm (known as an atrioventricular block), it could potentially suggest an abscess or pocket of pus in your heart. However, this result isn’t always accurate.
Lastly, it’s important to remember that sometimes tests can show negative results when there’s an abscess in the heart. For example, a person who initially had bacteria in their blood, but showed no signs of infection in their heart or changes in their heart rhythm, may have received treatment before further tests were conducted. Therefore, the tests may seem unreliable. Furthermore, if the tests weren’t done just right, this could also reduce the chances of getting accurate results.
Treatment Options for Cardiac Abscess (Heart Infection)
If you’re suspected of having infective endocarditis (IE) – an infection of the heart’s inner lining – or a cardiac abscess – a collection of pus around the heart, you’ll be treated right away with strong, broad-spectrum antibiotics. These antibiotics can kill a variety of bacteria, and you’ll get them intravenously (through your veins) until further tests pinpoint the exact type of bacteria causing your infection. You’ll need to take these antibiotics for at least six weeks to ensure the successful treatment of IE and a heart abscess.
Swift action for getting a surgery consultation is particularly important if you have a heart abscess because delaying surgery can increase the risk of serious illness or even death. The main aim of such surgery is to completely get rid of the infection and correct any issues with blood flow in your heart.
However, not everyone with a heart abscess or an infection that has spread around the heart needs surgery. You might not need surgery if:
- Your abscess is small (less than 1 cm)
- You’re not suffering from heart block, a condition where the electrical signals in the heart are delayed or blocked
- Your abscess isn’t getting worse during antibiotic treatment
- You don’t have a loose or leaky heart valve
If you don’t undergo surgery, your doctors will monitor you closely. They’ll use a procedure called a Transesophageal Echocardiogram (TEE) – a test that uses sound waves to create detailed pictures of your heart – at regular intervals (2 weeks, 4 weeks, and 8 weeks) after you’ve completed your course of antibiotics to make sure the infection is completely gone.
What else can Cardiac Abscess (Heart Infection) be?
When a cardiac abscess (an infection in the heart) is being diagnosed, there are a number of other conditions that doctors need to consider. These might present with similar symptoms but are distinctly different:
- Fever of unknown origin (FUO)
- First-degree atrioventricular block, a type of heart block
- Conditions following heart transplantation
- Conditions after a heart-lung transplantation
- Infections that occur after transplants of solid organs
- Infective endocarditis, an infection of the heart’s inner lining
- Mitral regurgitation, a leakage of blood backward through the mitral valve
- Myocardial infarction, commonly known as a heart attack
- Penetrating chest trauma, injury that pierces the skin and damages the heart
- Septic shock, a severe infection that affects the whole body
What to expect with Cardiac Abscess (Heart Infection)
If the condition is identified early and treatment is started right away, patients usually recover fast. However, without timely surgery, the patient’s chances of recovery generally aren’t as good.
Possible Complications When Diagnosed with Cardiac Abscess (Heart Infection)
Potential Complications:
- Heart block
- Arrhythmias, or irregular heart rhythms
- Congestive heart failure, which is a chronic condition where the heart doesn’t pump blood as it should
- Stroke, when the blood supply to part of your brain is interrupted or reduced
- Multiple organ failure, which is the failure of two or more organ systems
- Acute respiratory distress syndrome, a serious lung condition that causes low oxygen levels in the blood
- Death
Recovery from Cardiac Abscess (Heart Infection)
Patients typically require 6 to 8 weeks of antibiotics given through an injection. In addition, to prevent deep vein thrombosis (blood clots in the deep veins, usually in the legs), prophylaxis (preventative treatment) is needed. If a patient has a prosthetic valve, they may also require oral anticoagulants (blood thinners).
As these patients are very sick, providing them proper nutrition is necessary.
Furthermore, an exercise program can also help prevent the weakening of muscles and the formation of blood clots in the deep veins. So, regular physical activity is recommended.
Preventing Cardiac Abscess (Heart Infection)
It’s really important for patients to understand their illness. By understanding what’s going on in their body, they can play a key role in their own health. It’s also crucial that patients understand how significant prophylaxis, or preventative treatment, is in managing their condition. This can involve actions like taking medicines regularly, regular checkups, or lifestyle changes designed to prevent the illness from getting worse.
