Validation of Peripheral Pressure Volume Loops and Ultrasound-derived "Cardiac Power" by Comparison With Invasive Left Ventricular Pressure Volume Loops

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01750450
Recruitment Status : Completed
First Posted : December 17, 2012
Last Update Posted : May 1, 2014
Information provided by (Responsible Party):
University of Virginia

Brief Summary:
The investigators will generate pressure-flow loops and pressure-volume loops from aortic and left ventricular pressure waveforms and Doppler (desc. aorta) flow waveforms and compare left ventricular to arterial pressure-flow and pressure-volume loops as well as to cardiac power from the USCOM 1A device. The goal of this study is to test the hypothesis that non-invasive estimates of cardiac pressure-volume work (derived from ultrasound-based measurements) correlate with invasive estimates.

Condition or disease
Cardiovascular Disease

Detailed Description:

Extensive animal work by Suga et al. in the 1980s clearly demonstrate a relationship between left ventricular pressure volume area (PVA) and myocardial consumption of oxygen (MVO2).

PVA can be measured by combining radial artery pressures with ultrasound-derived estimates of aortic blood flow. Because the aorta and peripheral artery compartments are separated from the left ventricle by the aortic valve, the peripheral arterial pressures cannot perfectly approximate left ventricular pressures. However, because the majority of variation in the pressure volume loops is made up of changes in height and width (changes in the left ventricular end-diastolic curve are, by contrast, relatively small), both of which can be readily detected by changes in the peripheral arterial blood pressure tracing, this loss of information may be clinically insignificant.

USCOM, has developed a portable suprasternal Doppler probe (model 1A) capable of estimating left ventricular stroke volume; a unique feature of this device is its ability to utilize both stroke volume, heart rate, and mean arterial pressure in an attempt to measure cardiac power. This device has not been validated against invasive estimates of cardiac power.

Knowledge of MVO2 would be a useful clinical variable but is not widely available. The ability to non-invasively estimate MVO2 intraoperatively would give anesthesiologists the ability to measure the effect of hemodynamic interventions on myocardial consumption of oxygen and, when combined with stroke volume, estimate myocardial efficiency. Non-invasively estimates of MVO2 may also allow cardiologists a novel means of assessing the myocardium of patients with cardiovascular disease.

Study Type : Observational
Actual Enrollment : 65 participants
Observational Model: Cohort
Time Perspective: Prospective
Study Start Date : February 2013
Actual Primary Completion Date : March 2013
Actual Study Completion Date : June 2013

Elective left heart cath
Patients undergoing elective left heart catheterization will be consented for this study

Primary Outcome Measures :
  1. Correlation between left ventricular pressure volume area (PVA) and aortic PVA [ Time Frame: day of procedure ]
    The primary hypothesis of this study is that the slope of the regression line between left ventricular pressure volume area (PVA, as determined by simultaneous measurement of aortic outflow and left ventricular pressures) and aortic PVA (as determined by simultaneous measurement of aortic outflow and radial artery pressure) is not zero. The null hypothesis is that the probability that the slope of the regression line is different from a line with a slope of 0 is greater than 5%.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Adults 18 and over undergoing elective left heart catheterization

Inclusion Criteria:

  • Adult (18 or older)
  • Undergoing left heart catheterization

Exclusion Criteria:

  • Unable to visualize ascending aorta using ultrasound

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01750450

United States, Virginia
University of Virginia
Charlottesville, Virginia, United States, 22908
Sponsors and Collaborators
University of Virginia

Additional Information:
Responsible Party: University of Virginia Identifier: NCT01750450     History of Changes
Other Study ID Numbers: 16494
First Posted: December 17, 2012    Key Record Dates
Last Update Posted: May 1, 2014
Last Verified: April 2014

Keywords provided by University of Virginia:
Pressure Volume Area
Pressure Flow Area
Myocardial Work

Additional relevant MeSH terms:
Cardiovascular Diseases