In simple words: Meningococcal heart disease is a rare but serious complication of meningococcal infection, a bacterial infection often affecting the brain and spinal cord. It can cause inflammation of the heart's lining, muscle, or surrounding sac, leading to various heart-related problems.

Meningococcal heart disease encompasses various cardiac complications stemming from meningococcal infection, including endocarditis (inflammation of the heart's inner lining), myocarditis (inflammation of the heart muscle), and pericarditis (inflammation of the sac surrounding the heart). These conditions can manifest with altered heart rate and rhythm, fluctuating blood pressure, breathing difficulties, fluid retention, chest pain, muscle and joint aches, and impaired circulation.

Example 1: A patient presents with chest pain, rapid heart rate, and difficulty breathing following a recent diagnosis of meningococcal meningitis. Further investigation reveals inflammation of the pericardium, confirming meningococcal pericarditis., An individual with a history of meningococcal septicemia develops heart failure symptoms. Diagnostic tests show impaired heart muscle function due to meningococcal myocarditis., A child experiencing fever, headache, and stiff neck is diagnosed with meningococcal infection. Echocardiography reveals inflammation of the heart's inner lining, indicating meningococcal endocarditis.

Documentation for A39.5 should include evidence of meningococcal infection (e.g., positive blood culture, cerebrospinal fluid analysis), along with specific diagnostic findings related to heart involvement, such as electrocardiogram abnormalities, echocardiographic findings of pericarditis, myocarditis, or endocarditis, and cardiac marker levels.