Myocardial tuberculosis (TB) is a rare manifestation of tuberculosis affecting the heart muscle, known as the myocardium. It's infrequently diagnosed before death.
Myocardial TB is uncommon because the heart muscle's constant movement and rich blood supply make it relatively resistant to TB infection compared to other organs. When it does occur, it's usually secondary to the spread of TB from another site in the body through the bloodstream (hematogenous spread).
Characteristics of Myocardial TB:
- Rarity: It accounts for less than 0.1% of tuberculosis-related deaths based on postmortem studies.
- Secondary Infection: Most cases arise from the spread of TB from other locations in the body, such as the lungs, lymph nodes, or other organs.
- Diagnostic Challenges: Antemortem diagnosis is difficult due to its non-specific symptoms and the challenges in obtaining myocardial tissue for analysis.
Diagnosis
Diagnosis of myocardial TB typically requires a high index of suspicion, especially in patients with known TB elsewhere. Diagnostic tools may include:
- Imaging: Echocardiography, cardiac MRI, and CT scans can help visualize myocardial abnormalities.
- Biopsy: Endomyocardial biopsy is the gold standard for confirming the diagnosis, although it is invasive and not always feasible.
- Clinical Context: Considering the patient's history of TB or exposure to TB is crucial.
Symptoms
Symptoms of myocardial TB can be varied and non-specific, including:
- Heart failure: Shortness of breath, swelling in the legs.
- Arrhythmias: Irregular heartbeats.
- Pericarditis: Inflammation of the sac surrounding the heart, which can cause chest pain.
- Sudden death: Although rare, myocardial TB can lead to sudden cardiac arrest.
Treatment
Treatment for myocardial TB involves standard anti-tuberculosis medications. The duration of treatment is typically longer than for pulmonary TB, often lasting at least 6-9 months. Supportive care, such as medications for heart failure or arrhythmias, may also be necessary.
In summary, myocardial TB is a rare but serious condition involving TB infection of the heart muscle, usually as a result of TB spreading from another location in the body. Diagnosis is often challenging, and treatment involves anti-TB drugs along with supportive care.
