The investigators aim to correlate noninvasive pulmonary artery systolic pressure (PASP) measurements obtained with and without echocardiographic contrast (Optison) during transthoracic echocardiography (TTE) with those obtained invasively and simultaneously during right heart catheterization, as the gold standard.

In the United States, pulmonary hypertension (PHT) is an increasingly recognized cause of morbidity and mortality.

Echocardiography, due to its widespread use, versatility, portability, noninvasive nature, and safety, is routinely used as the primary method for diagnosis and evaluation of these patients. However, in this very cohort, its accuracy is frequently compromised by poor acoustic windows. The use of echocardiographic contrast (EC) in such patients may increase diagnostic accuracy, eliminate the need for performing more invasive, time-consuming, and expensive tests, and eliminate potential diagnostic and management errors.

Pulmonary Artery Systolic Pressure (PASP) is routinely measured noninvasively with transthoracic echocardiography (TTE) by obtaining the tricuspid regurgitant velocity (TRV) with continuous wave spectral Doppler and applying the modified Bernoulli equation.

The investigators aim to use the FDA approved perflutren-based EC agent Optison to augment inadequate TR CW spectral Doppler envelopes and determine if the TRV and PASP measurements obtained with the use of Optison correlate better with the invasive measurements obtained simultaneously during right heart catheterization as opposed to those measurements obtained without the use of EC.

Inclusion Criteria:

• consecutive patients (age ≥ 18 years old) undergoing right heart catheterization catheterization laboratory for various clinical indications as part of routine medical care;
• only patients with poor acoustic windows will be included (based on previous studies, body habitus);

Exclusion Criteria:

• atrial fibrillation or other irregular rhythms (bigeminy, frequent ectopy)
• pregnant women
• known allergy to perflutren, blood products, albumin
• patients who cannot receive blood products due to religious beliefs
• evidence of intracardiac right to left shunting

After obtaining informed written consent, investigators will enroll all consecutive patients (age ≥ 18 years old) undergoing right heart catheterization in the catheterization laboratory for various clinical indications as part of routine medical care.

This will be a prospective and multicenter study. The participating institutions are: North Shore University Hospital (Manhasset, NY), Long Island Jewish Medical Center (New Hyde Park, NY), and Mt Sinai Medical Center (NY, NY).