Related Experiment Video
Updated: May 20, 2026

Cox-Maze IV Procedure Concomitant with Valvular Surgery In Situs Inversus Dextrocardia: A Single-Center Experience in China
Published on: February 11, 2022
Fatal Platypnea-Orthodeoxia Syndrome After Transcatheter Tricuspid Valve Replacement: When HALT Reverses the Shunt
S A F Streukens1, F E C M Peeters1, R A L J Theunissen2
1Department of Cardiology, Maastricht University Medical Center+, Maastricht, the Netherlands; Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, Maastricht, the Netherlands.
Background:
Hypoattenuated leaflet thickening (HALT) after transcatheter tricuspid valve replacement (TTVR) is increasingly recognized, but its clinical consequences remain incompletely characterized.
Case Summary:
A 63-year-old woman developed severe platypnea-orthodeoxia 5 days after TTVR with the Evoque system. Cardiac computed tomography confirmed HALT of all 3 leaflets. HALT-induced functional stenosis elevated right atrial pressure, reversing a preexisting left-to-right shunt across a secundum atrial septal defect. Low-dose thrombolysis improved oxygen saturation from 69% to 90%, but was complicated by fatal intracranial hemorrhage.
Discussion:
Although platypnea-orthodeoxia from bioprosthetic tricuspid valve stenosis with shunt reversal has been described after surgical valve replacement, this represents to our knowledge its first occurrence after TTVR. The case illustrates a previously unrecognized mechanism of hemodynamic compromise and raises the question whether interatrial communications should be considered a relative contraindication for TTVR.
Take-Home Messages:
Screening for interatrial communications before TTVR is warranted. Standardized antithrombotic protocols and HALT surveillance strategies are urgently needed.
Related Concept Videos
Aortic Regurgitation I: Introduction
Mitral Stenosis I: Introduction
Mitral Stenosis IV: Nursing Management
Mitral Regurgitation I: Introduction
Aortic Regurgitation III: Medical Management
Cardiomyopathy III: Hypertrophic Cardiomyopathy
