Unilateral pulmonary oedema caused by eccentric mitral regurgitation—multimodality evidence of mechanism and reversal after transcatheter edge-to-edge repair: a case report

Unilateral pulmonary oedema is uncommon and frequently misattributed to pneumonia, delaying appropriate heart-failure care. Mechanistic clarification and demonstration of reversibility in a single patient can sharpen diagnostic reasoning and guide management.

An 88-year-old man presented with fever, inflammatory markers, and a right-upper-lobe ground-glass opacity. While pneumonia was suspected, transthoracic echocardiography revealed decompensated heart failure with severe mitral regurgitation (MR). Three-dimensional transoesophageal echocardiography (3D TEE) and contrast-enhanced computed tomography (CT) localized an eccentric MR jet towards the right superior pulmonary vein (RSPV). Pulmonary vein Doppler showed a vein-specific reversed systolic wave with diastolic extension in the RSPV, whereas the forward diastolic wave was preserved in other veins. After defervescence and partial decongestion, perfusion scintigraphy demonstrated segmental hypoperfusion matching the RSPV territory. Given high surgical risk, transcatheter edge-to-edge repair (TEER) was performed and reduced MR. After TEER, PV Doppler converted to forward systolic/diastolic waves, the chest radiograph cleared, and perfusion improved.

This case triangulates mechanism and reversibility by aligning morphologic (3D TEE/CT), haemodynamic (PV Doppler), and functional (perfusion scintigraphy) evidence, each demonstrated pre- and post-TEER. The multimodality concordance and TEER-demonstrated reversal strengthen causality beyond PV-flow-only reports and provide an actionable pathway for cases with unilateral opacities.