Establishing a Non-invasive Method to Measure Your Heart's Performance

Establishing a Non-invasive Method to Measure Heart Performance

The purpose of the study is to evaluate a new way to examine cardiac function, using software developed at Caltech. The experimental device is software loaded on an iPhone. The iPhone is used to capture a pulse (waveform) by simply placing the iPhone lightly over the neck where the carotid pulse can be felt. In this study the information collected from the iPhone app is compared to cardiac function data obtained from the current gold standard for measuring cardiac function, cardiac magnetic resonance imaging (MRI). Subjects referred from cardiologists will also generally have echocardiography information available for comparison with the iPhone app. For the study, subjects will have completely non-invasive studies done in one setting: The iPhone app to capture the waveforms (over carotid and radial (wrist) arteries), tonometry (another non-invasive method using a modified stethoscope), standard pulse oximetry, followed by a 30 minute MRI examination of the heart. A second complete study will be done about 6 months after the first. The complete study session takes about 1.5 hours.

Study Overview

• Status: Completed
• Conditions: Heart Failure
• Intervention / Treatment: Device: cardiac MRI

Detailed Description

Investigators at Caltech have developed an iPhone-based application that allows them to capture an arterial waveform using the iPhone camera held over the skin. Then based on the captured waveform and previous laboratory experiments and models, the investigators are able to calculate ejection fraction, the percentage of blood that goes out of the heart into the circulation with each beat. Previous studies suggested that the iPhone app measurements of ejection fraction were similar to those obtained with traditional cardiac echocardiography. In the current study the iPhone app measures are being compared to ejection fraction obtained using cardiac MRI. The iPhone also measures other physical properties of the heart and aorta that the investigators call "intrinsic frequencies". Using healthy subjects they have established the normal pattern/range of intrinsic frequencies, and in this study, a more diverse population of subjects (some with heart disease) will be studied, to determine how intrinsic frequency measures compare to traditional clinical measures of cardiac function.

• Study Type: Observational
• Enrollment (Actual): 72

Contacts and Locations

Study Locations

• United States
  • California
    • Pasadena, California, United States, 91105
      • Avicena LLC
    • Pasadena, California, United States, 91105
      • Huntington Medical Research Institutes MR Imaging Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adults with normal and abnormal cardiac function will be studied.

Description

Inclusion Criteria:

• Adult age 18-90, outpatients

Exclusion Criteria:

• Inability to lie flat for 30 minutes with periodic breath holding
• Metal implants or other standard contraindications to MRI
• Acute cardiac decompensation (active chest pain, shortness of breath)
• Hypotension (SBP<90 mm Hg)
• Claustrophobia
• Patient too large to fit in closed MRI

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adults able to undergo cardiac MRI exam; Adults able to undergo cardiac MRI	Device: cardiac MRI; cardiac MRI

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Magnetic resonance measures of cardiac function	Standard end-points of cardiac function such as chamber size and relaxation.	Within 1 month of study

Collaborators and Investigators

• Sponsor: Marie Csete MD, PhD
• Collaborators: University of Southern California; California Institute of Technology
• Investigators: Study Chair: Marie Csete, MD, PhD, Avicena LLC; Principal Investigator: Niema Pahlevan, PhD, University of Southern California

Publications and helpful links

General Publications

• Pahlevan NM, Tavallali P, Rinderknecht DG, Petrasek D, Matthews RV, Hou TY, Gharib M. Intrinsic frequency for a systems approach to haemodynamic waveform analysis with clinical applications. J R Soc Interface. 2014 Sep 6;11(98):20140617. doi: 10.1098/rsif.2014.0617.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2014
• Primary Completion (Actual): May 1, 2019
• Study Completion (Actual): May 1, 2019

Study Registration Dates

• First Submitted: September 12, 2014
• First Submitted That Met QC Criteria: September 15, 2014
• First Posted (Estimate): September 16, 2014

Study Record Updates

• Last Update Posted (Actual): May 14, 2019
• Last Update Submitted That Met QC Criteria: May 10, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Keywords: echocardiography; cardiac magnetic resonance imaging; arterial waveform; intrinsic frequency measures of cardiac function
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Heart Failure
• Other Study ID Numbers: HMRI-10Pico-1; CIT2014 (Other Identifier: California Institute of Technology Boswell Fellowship)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: A manuscript was submitted in February 2016 reporting results of the study. In editorial process.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No