Non-atrial/non-ventricular functional tricuspid valve regurgitation: a case report

Functional tricuspid regurgitation (fTR) is usually caused by annular dilation and leaflet tethering secondary to right atrial (RA) or right ventricular (RV) remodelling. Rarely, extrinsic factors may impair annular motion.

We report a 83-year-old woman with constrictive pericarditis who presented with right-sided heart failure and moderate tricuspid regurgitation. Multimodality imaging revealed a thickened pericardium, preserved RA and RV size, and a non-dilated, saddle-shaped annulus with markedly reduced motion. Following pericardiectomy, tricuspid annular mobility normalized, right-sided pressures decreased, and TR improved from moderate to mild. We introduce the term non-atrial/non-ventricular functional tricuspid regurgitation to describe this rare mechanism of isolated annular dysfunction caused by pericardial tethering.

This case highlights a novel, distinct, and reversible form of fTR caused by pericardial constraint rather than chamber remodelling. We propose the term non-atrial/non-ventricular fTR to describe this mechanism. Recognizing this entity may guide surgical decision-making and avoid unnecessary tricuspid valve intervention.