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

## TL;DR

A case report shows how unilateral pulmonary oedema from heart failure was reversed using a minimally invasive heart procedure.

## Contribution

The study provides multimodal evidence of mechanism and reversal of unilateral pulmonary oedema after TEER in a high-risk patient.

## Key findings

- Eccentric mitral regurgitation was localized to the right superior pulmonary vein using 3D TEE and CT.
- Pulmonary vein Doppler and perfusion scintigraphy confirmed reversed flow and hypoperfusion before TEER.
- TEER reversed the condition, restoring normal flow and clearing lung opacities.

## Abstract

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.