The purpose of this study is to build a repository of heart signals from eligible subjects. The experimental part of this study is the collection of the participant's heart signals using a device similar to a heart monitor called the Phase Signal Acquisition System. The signals will be electronically sent to a storage center, then compared to the results of the participant's heart catheterization and saved for future research and development activities sponsored by Analytics 4 Life. The study will include up to 2500 participants at up to 20 research sites in the United States and will require approximately one hour of the subject's time. There are no follow-up visits.

This study is for patients who have heart failure with pulmonary hypertension. Heart failure means that the heart cannot pump blood as well as normal. Pulmonary hypertension happens when the pressure in the blood vessels leading from the heart to the lungs is too high, blood flowing through the lungs is limited, and the pressure in the lungs increases when you are physically active, causing symptoms of shortness of breath and tiredness.

The study uses the Gradient device to see if can help treat heart failure with pulmonary hypertension. This device and therapy is still investigational, which means it is currently not approved by a regulatory agency (such as U.S Food and Drug Administration) for regular hospital use and it includes only individuals who choose to take part. Risks in this study include those for standard cardiac catheterization techniques and the administration of anesthesia including allergic reactions, low blood pressure, skin rash, or difficulty breathing; however, all of the risks may not be known. The study will last approximately 3 years and includes the following visits: Baseline/Screening, Procedure, Discharge, 1 month, 6 months and visits annually for 3 years. Study related procedures include a physical exam, blood testing, 6 minute walk test, echocardiogram, CT scan and a Right heart catheterization.