Noninvasive Cardiac Output Measurements in Patients With Pulmonary Hypertension Undergoing Exercise Testing

Subjects in this study have been diagnosed with pulmonary hypertension and their doctors
have referred them for an exercise test as part of their normal, routine care. The exercise
test will either be a treadmill test or a 6 minute walk test. During a treadmill test, a
patient typically walks on a treadmill while their heart is monitored using an
electrocardiogram, which records the electrical activity of the heart through 10 small
electrode patches attached to the skin of the chest, arms and legs. Additionally, heart rate
and blood pressure are monitored throughout the test. A 6-Minute Walk test requires patients
to walk for up to 6 minutes to determine how far they can go in order to measure the heart
function related to exercise.

The purpose of this study is to measure internal heart pressures using a device called
Noninvasive Cardiac Output Monitoring (NICOM) during an exercise test. Normally heart
pressures are measured during invasive (meaning that doctors have to go inside the body
using a needle or surgery) heart procedures. The NICOM device is non-invasive which means
the investigators do not have to go inside the body to obtain the heart pressure
measurements. In this study, the investigators will evaluate the non-invasive measurements
provided by the NICOM device during the exercise test and see how it relates to information
from some of subjects' past heart procedures. This research is being done to devise better,
less invasive ways to assess disease severity, track disease progression and evaluate
response to therapy.

The NICOM device is approved by the US Food and Drug Administration (FDA) to measure heart
pressures. This device is usually used when a patient can't undergo a right heart
catheterization. In this study, the investigators are using the device to gather heart
pressure measurements for research during the exercise test that is scheduled as part of the
subjects' normal, routine care. The research data is being used to devise better, less
invasive ways to assess disease severity, track disease progression and evaluate response to
therapy. The NICOM device is made by Cheetah Medical.