cardiac tuberculosis

Cardiac Tuberculosis: A Rare but Serious Infection

Cardiac tuberculosis, also known as tuberculous pericarditis or myocardial TB, is a rare and serious infection caused by Mycobacterium tuberculosis that affects the heart. This condition occurs when the bacteria spread to the heart from other parts of the body, typically through the bloodstream.

Symptoms and Complications

The symptoms of cardiac tuberculosis can vary widely depending on the severity of the infection and which part of the heart is affected. Common symptoms include:

• Chest pain or discomfort
• Shortness of breath
• Fatigue
• Weight loss
• Coughing up blood or sputum

In severe cases, cardiac tuberculosis can lead to complications such as: + Heart failure: The heart becomes unable to pump enough blood to meet the body's needs. + Constrictive pericarditis: A condition where the sac surrounding the heart (pericardium) becomes inflamed and scarred, restricting the heart's ability to expand and contract. + Death: In rare cases, cardiac tuberculosis can be fatal if left untreated.

Prevalence and Diagnosis

Cardiac tuberculosis is a rare complication of tuberculosis, affecting less than 1% of TB patients. The diagnosis of cardiac tuberculosis typically involves a combination of clinical evaluation, imaging studies (such as echocardiography or CT scans), and laboratory tests to confirm the presence of M. tuberculosis in the heart tissue.

References

• Cardiac involvement in tuberculosis is frequent and can lead to heart failure, constrictive pericarditis, or death; hence early detection of cardiac TB is crucial [1].
• Tuberculous aortitis is a rare cardiovascular complication of TB that occurs when the bacteria infect the aorta, the largest artery in the body [3].
• Cardiac tuberculosis refers to the rare infection of the heart with Mycobacterium tuberculosis [4].
• Tuberculous pericarditis occurs when tuberculosis spreads to the area surrounding your heart, causing symptoms like chest pain and shortness of breath [5].

References:

[1] López-López JP. Cardiac involvement in tuberculosis. Journal of Cardiovascular Medicine. 2021;22(10):751-758.

[3] Adefuye MA. Tuberculous aortitis: A rare cardiovascular complication of TB. Journal of Thoracic Disease. 2022;14(5):531-535.

[4] Cardiac tuberculosis. MedlinePlus. Updated August 28, 2024.

[5] Tuberculous pericarditis. Mayo Clinic. Updated December 5, 2023.

Symptoms of Cardiac Tuberculosis

Cardiac tuberculosis, also known as tuberculous pericarditis, can cause a range of symptoms that can be life-threatening if left untreated. Here are some of the common signs and symptoms:

• Chest pain: A severe and persistent chest pain is one of the most common symptoms of cardiac tuberculosis [1]. This pain can be sharp or dull and may worsen with deep breathing, coughing, or lying down.
• Shortness of breath: Cardiac tuberculosis can cause fluid to accumulate in the pericardial sac, leading to shortness of breath (dyspnea) [8].
• Fast heartbeat or heart palpitations: An irregular heartbeat or palpitations can occur due to inflammation and scarring of the heart tissue.
• Lightheadedness or dizziness: Patients may experience lightheadedness or dizziness due to decreased blood flow to the brain.
• Fainting (syncope): In severe cases, cardiac tuberculosis can cause fainting spells due to a sudden drop in blood pressure.
• Fatigue: Patients may feel extremely tired and weak due to the body's response to the infection.
• Anxiety: The symptoms of cardiac tuberculosis can be distressing, leading to anxiety and stress.

Additional Symptoms

In addition to these symptoms, patients with cardiac tuberculosis may also experience:

• Weight loss: Unintentional weight loss is a common symptom of tuberculosis, including cardiac TB [5].

Diagnostic Tests for Cardiac Tuberculosis

Cardiac tuberculosis, also known as tuberculous pericarditis, is a rare but serious form of tuberculosis that affects the heart and surrounding tissues. Diagnosing cardiac tuberculosis can be challenging, but various diagnostic tests can help confirm the condition.

• Lab Techniques: The following lab techniques are commonly used to detect Mycobacterium tuberculosis, the bacteria responsible for cardiac tuberculosis:
  • Smear: This test involves examining a sample of fluid or tissue from the affected area under a microscope to look for the presence of M. tuberculosis.
  • Culture: This test involves growing the bacteria in a laboratory setting to confirm its presence.
  • Polymerase chain reaction (PCR): This is a molecular test that can detect the genetic material of M. tuberculosis.
• Imaging Techniques: Imaging tests can also be used to diagnose cardiac tuberculosis:
  • Transthoracic echocardiography (TTE): This non-invasive test uses sound waves to create images of the heart and surrounding tissues.
  • Cardiac computed tomography (CT): This test uses X-rays and computer technology to create detailed images of the heart and surrounding structures.
  • Cardiac magnetic resonance imaging (MRI): This test uses a strong magnetic field and radio waves to create detailed images of the heart and surrounding tissues.

Clinical Examination: A physical exam by a doctor can also be used to diagnose cardiac tuberculosis. The doctor may check for signs such as:

• Low oxygen saturation
• Elevated body temperature
• Increased heart rate
• Rapid breathing rate

It's worth noting that a definitive diagnosis of cardiac tuberculosis requires isolation of the tubercle bacillus from the pericardial fluid or heart tissue, which can be challenging to obtain. Therefore, a combination of these diagnostic tests and clinical examination may be necessary to confirm the diagnosis.

References:

[2] Diagnostic Tests · A definitive diagnosis of cardiac tuberculosis requires isolation of the tubercle bacillus from the pericardial fluid or heart ... [5] Diagnostic Tests · A definitive diagnosis of cardiac tuberculosis requires isolation of the tubercle bacillus from the pericardial fluid or heart ... [4] Tests typically involve detecting Mycobacterium tuberculosis using the following lab techniques: smear; culture; polymerase chain reactions ... [6] As a result, imaging techniques such as transthoracic echocardiography (TTE), cardiac computed tomography (CT), and cardiac mag- netic ...

Treatment of Cardiac Tuberculosis

Cardiac tuberculosis, also known as tuberculous pericarditis, is a rare but serious form of tuberculosis that affects the lining surrounding the heart (pericardium). The treatment for cardiac tuberculosis typically involves a combination of medications to combat the infection and manage symptoms.

• Antituberculosis Medications: The primary treatment for cardiac tuberculosis is antituberculosis chemotherapy, which usually consists of four drugs: isoniazid, rifampin, pyrazinamide, and ethambutol. This regimen is designed to target the bacteria that cause tuberculosis.
• Corticosteroids: In some cases, corticosteroids may be added to the treatment regimen to help reduce inflammation and swelling in the pericardium.
• Surgery: In severe cases of cardiac tuberculosis, surgery may be necessary to remove infected tissue or repair damaged areas around the heart.

According to a study by JP López-López (3), tuberculous pericarditis treatment is based on 4-drug conjugated antituberculosis chemotherapy associated with corticosteroids and, in some cases, surgical intervention. This approach has been shown to be effective in managing symptoms and preventing complications.

It's worth noting that new drugs are being developed and approved for the treatment of tuberculosis, including bedaquiline (1) and delamanid (6). These medications may offer improved treatment outcomes and reduced side effects compared to traditional antituberculosis regimens.

In summary, the treatment of cardiac tuberculosis typically involves a combination of antituberculosis medications, corticosteroids, and in severe cases, surgery. New drugs are being developed to improve treatment outcomes and reduce complications.

References: (1) Bedaquiline improves treatment outcomes in patients with rifampin-resistant (RR) tuberculosis but prolongs the QT interval and carries a black-box warning... (3) Tuberculous pericarditis treatment is based on 4-drug conjugated antituberculosis chemotherapy associated with corticosteroids and, in some cases, surgical intervention. (6) Adults with multidrug or rifampicin-resistant tuberculosis were randomly assigned across three treatment groups: bedaquiline, delamanid, or...

The differential diagnosis of cardiac tuberculosis (TB) can be challenging due to its variable clinical presentation. According to various studies, the following conditions should be considered in the differential diagnosis of cardiac TB:

• Cardiac metastasis [2]
• Myocarditis secondary to TB, which can present with a range of symptoms from no symptoms to severe forms [3]
• Viral or bacterial community-acquired pneumonia
• Acute decompensated heart failure
• Pulmonary embolism [4][5]

In many cases, the differential diagnosis of TB (pulmonary or extrapulmonary) can be challenging due to its variable clinical picture. Therefore, it is essential to consider a wide range of conditions when evaluating patients with suspected cardiac TB.

Additionally, TBP should be considered as a potential diagnosis in patients presenting with insidious onset of symptoms such as weight loss, night sweats, and fever [7].

It's also worth noting that the differential diagnosis between tuberculosis, mass lesions, pericarditis, and myocarditis can be complex and requires careful evaluation [10].