Stopped: Low recruitment
This is a non-invasive study using a standard doppler echocardiographic transducer which records signals emanating from the lungs (TPD). These signals are caused by pulsation of blood vessels in the lung tissue. The innovations in this study are: 1. The software processing of the reflected ultra-sound waves from the lung rendering a reproducible, clear and strong signal in sync with the cardiac cycle, 2. The observation based on pilot studies that blowing hard against resistance during recording (something called a Valsalva maneuver), affects the lung signal weakening it and even obliterating it as the pressure rises. The investigators hypothesis is that since the signal comes from the blood vessels in the lung, the pressure at which the recorded signal disappears during the Valsalva maneuver represents the blood pressure in the lungs.
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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Reaching target enrollment number
Timeframe: 1-2 years