48 µl of Sonazoid microbubbles (GE Healthcare, Oslo, Norway) will be co-infused at a rate of 0.024 µl/kg body weight/minute together with a 0.9% sodium chloride solution infused at a rate of at least 2 ml/min.

Whenever a patient undergoes cardiac catheterization, which routinely includes intracardiac pressure monitoring using a pressure catheter, as part of their standard clinical care and agrees to participate in the study, we will acquire research data. With Sonazoid infusion, SHAPE algorithm will be initiated to determine optimum acoustic pressure. Then, at the optimum acoustic pressure, SHAPE specific data will be acquired from the cardiac chambers and aorta synchronously with the pressures recorded by the catheter (as a part of the patient's standard of care). After acquiring the ultrasound imaging data, the remainder of the heart catheterization will be completed by the attending cardiologist according to the patients' standard of care.

The Pearson correlation coefficient was computed between the simultaneously acquired subharmonic signal and pressure catheter data (i.e., waveforms) for each participant. The Pearson correlation coefficient was used for comparing waveforms given the underlying data and pressure values used for comparisons followed a normal distribution. Values reported will be the mean Pearson correlation coefficient values between the subharmonic waveforms and pressure catheter waveforms obtained.

Based on the distribution of the differences in cardiac pressure values obtained using the SHAPE technique and the clinical pressure catheter, either a two-tailed paired t test (normal distribution) or Wilcoxon signed rank test (nonnormal distribution) was used to compare the SHAPE technique to the reference standard. Bonferroni corrections were used for multiple comparisons

48 µl of Sonazoid microbubbles (GE Healthcare, Oslo, Norway) will be co-infused at a rate of 0.024 µl/kg body weight/minute together with a 0.9% sodium chloride solution infused at a rate of at least 2 ml/min.

Sonazoid: Whenever a patient undergoes cardiac catheterization, which routinely includes intracardiac pressure monitoring using a pressure catheter, as part of their standard clinical care and agrees to participate in the study, we will acquire research data. With Sonazoid infusion, SHAPE algorithm will be initiated to determine optimum acoustic pressure. Then, at the optimum acoustic pressure, SHAPE specific data will be acquired from the cardiac chambers and aorta synchronously with the pressures recorded by the catheter (as a part of the patient's standard of care). After acquiring the ultrasound imaging data, the remainder of the heart catheterization will be completed by the attending cardiologist according to the patients' standard of care.

The Pearson correlation coefficient was computed between the simultaneously acquired subharmonic signal and pressure catheter data (i.e., waveforms) for each participant. The Pearson correlation coefficient was used for comparing waveforms given the underlying data and pressure values used for comparisons followed a normal distribution. Values reported will be the mean Pearson correlation coefficient values between the subharmonic waveforms and pressure catheter waveforms obtained.

Data was not acquired in all the enrolled patients due to health concerns during the catheterization procedure, software and/or hardware issues related to the data acquisition process, patient scheduling and/or arrival of emergency cases, and withdrawn consent before the procedure.

48 µl of Sonazoid microbubbles (GE Healthcare, Oslo, Norway) will be co-infused at a rate of 0.024 µl/kg body weight/minute together with a 0.9% sodium chloride solution infused at a rate of at least 2 ml/min.

Sonazoid: Whenever a patient undergoes cardiac catheterization, which routinely includes intracardiac pressure monitoring using a pressure catheter, as part of their standard clinical care and agrees to participate in the study, we will acquire research data. With Sonazoid infusion, SHAPE algorithm will be initiated to determine optimum acoustic pressure. Then, at the optimum acoustic pressure, SHAPE specific data will be acquired from the cardiac chambers and aorta synchronously with the pressures recorded by the catheter (as a part of the patient's standard of care). After acquiring the ultrasound imaging data, the remainder of the heart catheterization will be completed by the attending cardiologist according to the patients' standard of care.