Hereditary Hemorrhagic Telangiectasia Clinical Trials

The goal of this clinical trial is to learn how well the SONAS ultrasound device can detect right-to-left shunts of adults with hereditary hemorrhagic telangiectasia (HHT) who are already scheduled for a contrast bubble echocardiogram (TTCE). The main questions it aims to answer are: 1. How accurately does SONAS detect right-to-left shunts compared to the standard TTCE test? 2. Can SONAS results help tell the difference between shunts in the heart and shunts in the lungs? Participants will wear a headband with the SONAS device on the head while they undergo their routine TTCE bubble test. They will receive the usual contrast (agitated saline) through a vein, and both SONAS and TTCE signals will be recorded at the same time. There will be one examination in rest, and one during a breathing exercise (the Valsalva manoeuvre).