Sudden cardiac death and tuberculosis - how much do we know?

Area of Science:

• Cardiology
• Infectious Diseases
• Pathology

Background:

• Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a significant global health threat, primarily affecting the lungs.
• TB myocarditis, an inflammation of the heart muscle due to TB, is an underrecognized cause of sudden cardiac death (SCD), particularly in young, asymptomatic individuals.
• Unlike other causes of SCD, TB myocarditis lacks identifiable risk factors, complicating early detection and intervention.

Purpose of the Study:

• To highlight TB myocarditis as a cause of SCD.
• To review existing literature on TB myocarditis and SCD.
• To propose a unifying diagnostic framework for TB myocarditis.

Main Methods:

• Literature review of reported cases of TB myocarditis SCD.
• Analysis of autopsy findings in TB myocarditis SCD cases.
• Postulation of pathogenic mechanisms for TB myocarditis SCD.

Main Results:

• Few cases of TB myocarditis SCD reported since 1977, diagnosed predominantly at autopsy.
• Majority of cases show extensive myocardial TB infiltration without systemic symptoms.
• Hypothesized mechanisms include ventricular tachyarrhythmia (TB myocarditis) and cardiopulmonary collapse/bradycardia (pulmonary TB SCD).

Conclusions:

• TB myocarditis is a distinct entity causing SCD, often presenting without typical cardiac risk factors.
• Current anti-TB chemotherapy may not prevent SCD in TB myocarditis.
• A unifying diagnostic system incorporating molecular techniques is proposed, requiring further validation.