Critical tricuspid regurgitation secondary to ruptured chordae tendineae mimicking a mass on the tricuspid valve in a newborn.

Tricuspid regurgitation (TR) due to chordal rupture is a rare condition in newborns. We present a newborn with critical TR. Cross-sectional echocardiography demonstrated a dense, mobile mass localized at the tricuspid valve and resembling an atrial thrombus or myxoma. At operation, ruptured chordae tendineae of the tricuspid valve were found, forming a tangled mass. Histopathologic examination revealed collagen degeneration and calcification in the ruptured chordae, producing the hyperechoic image. It should be emphasized that ruptured chordae of the tricuspid valve might mimic a tricuspid valve myxoma or a thrombus on cross-sectional echocardiography.