Abstract 17227: A New Noninvasive iPhone Application to Monitor Left Ventricle Ejection Fraction in Heart Failure Patients
Introduction: Health care systems have expended major effort on monitoring heart failure (HF) status in outpatients, with a focus on reducing re-admission for decompensated heart failure and adjusting out-patient treatment. Here we present a noninvasive technique to monitor left ventricle ejection fraction (LVEF) that requires only a standard iPhone and an iPhone application. Our method is based on a new mathematical method called intrinsic frequency (IF) that views the left ventricle-arterial system as a coupled dynamic system.
Methods: A custom smart phone application was written to collect noninvasive carotid pulse waveforms using an Apple iPhone 5S. LVEF was computed from these waveforms using intrinsic frequencies. A General Electric 1.5 Tesla clinical scanner was used for cardiac MRI exam. The iPhone waveforms were collected at the same session and at the same location as the cardiac MRI. The major end-point of analysis was comparison of LVEF obtained with IF methods (EFiPhone) vs. LVEF measured from short axis cardiac MRI images (EFMRI).
Results: A total of seventy-two adult volunteer subjects ranging in age from 20-92 years participated in this study. On the basis of examination by a cardiologist, eleven subjects were diagnosed with HF with reduced ejection fraction (HFrEF). The correlation between EFiPhone and EFMRI was 0.74 (r=0.74, P<0.0001) among all subjects. The correlation between EFiPhone and EFMRI was very strong among HF patients (r=0.94, p<0.0001 ). The regression line in HF subgroup was EFMRI=0.48*(EFiPhone)+6.1 (Fig 1).
Conclusions: These results suggest that a noninvasive technique using an iPhone application and standard iPhone can be used to calculate LVEF values close to those obtained using MRI. These observations have important clinical implications for tracking cardiac function in HF patients.
Author Disclosures: N.M. Pahlevan: Research Grant; Modest; Postdoctoral Fellowship, Western States Affiliate, American Heart Association. D. Rinderknecht: None. P. Tavallali: None. M. Razavi: None. T.T. Tran: None. M. Fong: None. R.A. Kloner: None. M. Csete: None. M. Gharib: None.
- © 2016 by American Heart Association, Inc.