Lyme Myopericarditis With Effusive-Constrictive Physiology

BACKGROUND: Lyme cardiac involvement typically presents with atrioventricular (AV) conduction disease. Pericardial involvement with effusive-constrictive physiology is uncommon. Distinguishing inflammatory from fixed constriction has important management implications. CASE SUMMARY: A 45-year-old man developed progressive pleuritic chest pain and dyspnea 4 months after a tick bite. An electrocardiogram showed diffuse ST-segment elevation with PR-segment depression without atrioventricular block, and he was treated for acute pericarditis. Persistent symptoms prompted echocardiography demonstrating moderate pericardial effusion and new left ventricular systolic dysfunction (left ventricular ejection fraction 35%-40%). Lyme serology showed IgG Western blot reactivity (10/10 bands), consistent with late disseminated Lyme disease. Cardiac magnetic resonance demonstrated diffuse pericardial thickening/enhancement with pericardial T2 edema, loculated effusion, right ventricular tethering, and ventricular interdependence. Right-heart catheterization confirmed effusive-constrictive physiology. He was treated medically, with recovery of left ventricular function without pericardiectomy. DISCUSSION: Serial cardiac magnetic resonance and invasive hemodynamics identified a reversible inflammatory phenotype supporting conservative therapy. TAKE-HOME MESSAGE: Multimodality imaging can identify a reversible inflammatory phenotype and guide therapy in effusive-constrictive pericarditis.