Understanding Heart Infection: Causes, Types, and Management
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
A heart infection is a condition where microbes like bacteria, viruses, or fungi infect the heart's muscle, valves, or surrounding membranes [1]. The infection leads to inflammation and can impair the heart's ability to pump blood effectively. The most common forms include endocarditis, myocarditis, and pericarditis, each affecting a different part of the heart's anatomy [1].
What the research says
Antibiotics before dental work lowered endocarditis risk, but only in high-risk people. A systematic review and meta-analysis of 30 studies (1,152,345 infective endocarditis cases) found that, in people at high risk, antibiotic prophylaxis was associated with a lower risk of endocarditis after invasive dental procedures (pooled relative risk 0.41, 95% CI 0.29–0.57), while no association was proven for people at low or unknown risk (Sperotto et al., JAMA Cardiology, 2024) [2].
Endocarditis complicated by shock carries a very high risk of death. Pooling seven observational studies, in-hospital mortality among adults with infective endocarditis and septic or cardiogenic shock was 62.3% (95% CI 48.3–74.5%), and Staphylococcus aureus was the most common pathogen in the available data (Pîrîianu-Masgras et al., Heart Failure Reviews, 2025) [3].
An aortic root abscess worsens outcomes after endocarditis surgery. In a meta-analysis of eight observational studies (2,266 patients; 637 with an aortic root abscess), in-hospital mortality was 15.7% with an abscess versus 12.8% without (risk ratio 1.65, 95% CI 1.28–2.13), and endocarditis recurrence was 10.6% versus 4.8% (Emara et al., Heart & Lung, 2026) [4].
Key Takeaways
Feature | Description |
Primary Types | Endocarditis, Myocarditis, and Pericarditis. |
Common Causes | Bacteria, viruses, fungi, and parasites [1]. |
High-Risk Groups | Adults over 65, individuals with prior heart surgery, and IV drug users [1]. |
Top Symptoms | Chest pain, fatigue, fever, and shortness of breath [1]. |
Diagnostic Tools | Blood tests, Chest X-rays, CT/MRI scans, and biopsies [1]. |
Main Treatments | Antibiotics, anti-inflammatories, and heart valve surgery [1]. |
What is a heart infection?
A heart infection develops when microbes or other irritants invade the heart's structure. These invaders most commonly include bacteria and viruses, though fungal infections can also occur, albeit less frequently [1]. The infection typically targets specific areas, such as the heart muscle (myocardium), the valves, the inner lining (endocardium), or the outer protective sac (pericardium) [1].
The Three Main Types
Heart infections are categorized based on the specific tissue affected:
Endocarditis: This is an infection of the inner lining of the heart chambers and valves [1]. It is often caused by bacteria entering the bloodstream [1].
Myocarditis: This involves inflammation of the heart muscle itself, which can weaken the heart and lead to heart failure or arrhythmias [1].
Pericarditis: This is the inflammation of the pericardium, the thin, two-layered sac that surrounds the heart [1].
Who is at Risk?
While serious heart infections are uncommon for the general public, certain factors increase vulnerability. Individuals over the age of 65, those who have undergone previous heart surgeries, and people who use injected recreational drugs are at a significantly higher risk [1].
What are the symptoms and warning signs of a heart infection?
Symptoms of a heart infection can vary widely depending on the type and severity of the condition. However, several common clinical signs often overlap across all three types.
Common Clinical Signs
Chest Pain and Shortness of Breath: Physical discomfort and difficulty breathing are primary indicators of heart stress [1].
Systemic Symptoms: Fever, fatigue, night sweats, and joint pain or body aches are common as the body fights the infection [1].
Physical Changes: Fluid buildup (edema) in the legs, ankles, feet, or abdomen is a sign of reduced heart efficiency [1].
Heart Rhythm Issues: A rapid heartbeat (arrhythmia) or pounding sensations (palpitations) may occur [1].
Type-Specific Indicators
Endocarditis is uniquely associated with a heart murmur, which is a specific sound heard by providers as blood flows through the heart [1]. Other less common signs of endocarditis include:
What causes and triggers a heart infection?
The cause of a heart infection depends heavily on the specific type of inflammation present.
Endocarditis Triggers
Bacteria typically enter the bloodstream through:
Pericarditis and Myocarditis Triggers
These conditions are often triggered by:
Infections: Viruses like SARS-CoV-2 (COVID-19), coxsackievirus, and adenovirus are common culprits [1]. Bacterial, fungal, and parasitic infections can also be responsible [1].
Autoimmune Conditions: Diseases such as lupus, rheumatoid arthritis, and scleroderma can cause the immune system to attack heart tissue [1].
Other Factors: Chest injuries, kidney failure, tumors, and certain medications or radiation treatments can lead to inflammation [1].
How is a heart infection diagnosed and tested?
Healthcare providers use a combination of physical exams and advanced technology to diagnose heart infections. A stethoscope is first used to check for heart murmurs [1], followed by more detailed tests. For suspected endocarditis, these usually include blood cultures to find germs in the blood and an echocardiogram (ultrasound of the heart) to look at the valves.
Test Type | Purpose |
Blood Tests | Check for inflammatory proteins, antibodies, and white blood cell counts [1]. |
Chest X-ray | Observe changes in the heart's shape, size, and potential fluid buildup [1]. |
CT or MRI Scan | Provide detailed images to look for inflammation or tissue thickening [1]. |
Heart Biopsy | Extract a small tissue sample to identify specific microbes or inflammation [1]. |
How is a heart infection managed and treated?
Treatment strategies are tailored to the underlying cause and the severity of the patient's symptoms.
Medical Therapies
Medication is the first line of defense for most heart infections. Common prescriptions include:
Surgical Intervention
In severe cases where medication is insufficient, surgery may be required. This can include heart valve surgery to repair or replace damaged valves, or in the most extreme instances, a heart transplant [1].
What is the outlook for a heart infection, and can it be prevented?
The prognosis for a heart infection varies depending on the specific disease and its severity [1]. Prompt care is critical to avoiding long-term complications [1]. Call 911 or your local emergency number right away for chest pain, severe shortness of breath, fainting, or sudden weakness or trouble speaking.
Potential Complications
If left untreated, heart infections can lead to life-threatening issues, including:
Learn more about heart infections from Cleveland Clinic.
Conclusion
Heart infections are serious conditions that require immediate medical attention. By understanding the different types—endocarditis, myocarditis, and pericarditis—patients can better recognize the warning signs and seek life-saving treatment. Whether managed through targeted medication or advanced surgery, the goal is always to reduce inflammation and protect long-term cardiac health.
Frequently Asked Questions (FAQ)
What is a heart infection?
It is an invasion of heart tissue by microbes like bacteria or viruses.
What are the three main types?
Endocarditis, myocarditis, and pericarditis.
What is endocarditis?
An infection of the heart's inner lining and valves.
What is myocarditis?
Inflammation of the heart muscle.
What is pericarditis?
Inflammation of the sac surrounding the heart.
Are heart infections common?
No, they are relatively rare for most people.
Who is at highest risk?
People over 65, those with heart surgery history, and IV drug users.
Can bacteria cause heart infections?
Yes, bacterial infections are a common cause of endocarditis.
Can viruses cause heart infections?
Yes, viruses like COVID-19 can lead to myocarditis or pericarditis.
Can fungi cause heart infections?
Yes, though it is less common than bacterial or viral causes.
What are the most common symptoms?
Chest pain, fatigue, fever, and shortness of breath.
Does heart infection cause chest pain?
Yes, it is a very common symptom.
Can heart infections cause swelling?
Yes, fluid buildup (edema) in the legs and abdomen can occur.
What is a heart murmur?
A sound heard via stethoscope that can indicate endocarditis.
What are Janeway lesions?
Red spots on the palms or soles associated with endocarditis.
What are Osler’s nodes?
Red spots under the skin of fingers or toes.
Can heart infections cause night sweats?
Yes, this is a systemic sign of infection.
How do providers diagnose heart infections?
Through blood tests, imaging (X-ray/MRI), and biopsies.
What do blood tests show?
Levels of inflammatory proteins and white blood cell counts.
Is a heart biopsy always necessary?
No, it is used in specific instances to identify inflammation.
How is endocarditis treated?
Typically with antibiotics or valve surgery.
What medications treat pericarditis?
Anti-inflammatories like NSAIDs or colchicine.
Can heart infections be treated at home?
Most require medical supervision and prescription drugs.
Is surgery required for all heart infections?
No, only for serious or unresponsive cases.
What is heart valve surgery?
A procedure to repair or replace infected heart valves.
Can a heart infection lead to a transplant?
Yes, in the most severe cases.
Can dental hygiene affect the heart?
Yes, poor hygiene can allow bacteria into the bloodstream.
Are dental procedures a risk?
Yes, they can introduce bacteria if the gums are cut.
What is the risk of IV drug use?
It is a major cause of bacterial endocarditis.
Can autoimmune diseases cause heart inflammation?
Yes, lupus and RA are known triggers.
Can COVID-19 affect the heart?
Yes, it can cause myocarditis.
What is a pulmonary embolism?
A blood clot in the lung artery, a possible complication.
Can heart infections cause a stroke?
Yes, as a potential complication of the disease.
Can heart infections lead to heart failure?
Yes, if the muscle or valves are severely damaged.
What is sudden cardiac death?
A potential fatal complication of untreated heart infection.
Can children get heart infections?
Yes. Heart infections can affect people of any age, although serious cases are rare for most people.
Is pericarditis the same as a heart attack?
No, but it can cause similar chest pain.
How long does treatment take?
It varies depending on the infection's severity.
Can heart infections recur?
Yes, especially if the underlying risk factors aren't managed.
Does a fever always mean a heart infection?
No, but it is a common symptom when combined with chest pain.
What are petechiae?
Small red or purple spots on the skin or eyes.
Can kidney failure cause heart issues?
Yes, it can lead to uremic pericarditis.
Are parasites a cause?
Yes, though more common in specific geographic regions.
Can radiation cause heart inflammation?
Yes, it is a less common cause of myocarditis.
What is colchicine?
An anti-inflammatory drug used for pericarditis.
What are corticosteroids?
Medications used to reduce severe inflammation.
Can a chest injury affect the heart?
Yes, traumatic pericarditis can occur after an accident.
Is myocarditis contagious?
The underlying virus may be, but the heart inflammation itself is not.
Can heart infections cause weight loss?
Yes, unexplained weight loss is a sign of endocarditis.
What is the best way to prevent heart infection?
Good dental hygiene and avoiding IV drug use.
References
Cleveland Clinic. Heart Infection. Cleveland Clinic. Last updated November 8, 2021. https://my.clevelandclinic.org/health/diseases/22054-heart-infection
Sperotto F, France K, Gobbo M, et al. Antibiotic prophylaxis and infective endocarditis incidence following invasive dental procedures: a systematic review and meta-analysis. JAMA Cardiology. 2024;9(7):599-610. PMID 38581643. https://doi.org/10.1001/jamacardio.2024.0873
Pîrîianu-Masgras RB, Mebazaa A, Savarese G, et al. Infective endocarditis complicated by shock: a systematic review and meta-analysis. Heart Failure Reviews. 2025;30(6):1377-1395. PMID 40884710. https://doi.org/10.1007/s10741-025-10556-5
Emara A, Emara M, Aldemerdash MA, et al. Impact of aortic root abscess on outcomes in infective endocarditis and predictors of in-hospital mortality: a meta-analysis. Heart & Lung. 2026;75:337-346. PMID 41172899. https://doi.org/10.1016/j.hrtlng.2025.10.009
Disclaimer
The information provided in this article is for educational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional for diagnosis and treatment of any health condition.
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