Atrio-Ventricular Block by Legionella Disease.

Area of Science:

• Infectious Diseases
• Cardiology

Background:

• Legionnaires' disease primarily affects the lungs but can present with systemic manifestations, including rare cardiac involvement such as endocarditis, myocarditis, pericarditis, and pericardial effusion.
• The COVID-19 pandemic created a challenging diagnostic environment, potentially masking or mimicking other infections.

Observation:

• A 72-year-old male presented with symptoms suggestive of respiratory infection (cough, fever) during the COVID-19 pandemic.
• Initial investigations revealed COVID-19-like chest X-ray findings and Mobitz type II atrio-ventricular block on electrocardiogram, despite negative serial COVID-19 PCR tests.
• A positive urinary Legionella antigen test was crucial for diagnosis.

Findings:

• The patient's bradycardia and heart block significantly improved following treatment with amoxicillin/clavulanic acid and clarithromycin, indicating Legionella as the likely cause.
• Despite clinical improvement with antibiotics, the patient required implantation of a permanent pacemaker due to persistent Mobitz type II atrio-ventricular block.

Implications:

• This case highlights the importance of considering Legionnaires' disease in patients presenting with cardiac conduction abnormalities, even during pandemics.
• Early diagnosis and appropriate antibiotic therapy are critical for managing cardiac manifestations of Legionnaires' disease.
• Persistent atrio-ventricular block may necessitate long-term cardiac pacing, underscoring the potential severity of systemic Legionella infections.