Ultrasonographers attempted to acquire standard
echocardiography projections of parasternal (long axis and
short axis); subcostal; and apical 2-, 3-, and 4-chamber views
with PME (Vscan) before doing comprehensive TTE (Philips iE33
xMATRIX) with an echocardiograph system. Ultrasonographers
were encouraged to complete the PME examination in 5 minutes
or less to simulate the length of time a physician might use
the PME device as part of the physical examination. The color
flow function of the device was turned off to facilitate rapid
acquisition of images in keeping with a first-pass examination.
Two cardiology fellows with two months or less of basic
echocardiography training and two faculty cardiologists with
advanced training in echocardiography individually interpreted
PME images, which included measurements of the left
ventricular end-diastolic dimensions in the parasternal long-axis
view with electronic calipers built into the software of the PME
device. Color flow and mitral regurgitation were not assessed to
facilitate rapid acquisition of images consistent with a first-pass
Accuracy of interpretation of PME images by faculty and fellows
is detailed in Table 1 as shown. Physicians with less experience
disagreed with each other about what the PME images showed
more than physicians with more experience. The findings are
promising but suggest the device is not ready for general
heart assessment use by clinicians untrained in obtaining and
interpreting cardiac images.
Liebo, MD, M., Israel, MD, R., Lillie, PhD, E., Smith, MD, M., Rubenson, MD, D., & Topol, MD, E. (2011).
Is Pocket Mobile Echocardiography the Next-Generation Stethoscope? A Cross-sectional
Comparison of Rapidly Acquired Images With Standard Transthoracic Echocardiography.
Annals of Internal Medicine, 155(1), 33-38.
Eric J. Topol, MD
is a cardiologist at Scripps in La Jolla, California. He leads the flagship NIH supported Scripps Translational
Science Institute and is Professor of Genomics at The Scripps Research Institute. He also serves as Chief
Academic Officer of Scripps Health and is a co-founder of the West Wireless Health Institute. In 2012, he
was voted the most influential physician executive in the United States by Modern Healthcare. He was
elected to the Institute of Medicine of the National Academy of Sciences and is one of the top 10 most
cited researchers in medicine.
Table 1. Visualizability, Accuracy, and Variability of Readings of Images Obtained by Using Pocket Mobile Echocardiography
Abnormal, Visualized, True-Positive Plus True-Negative
Readings (Visualized/Total), %/%*
Overall Attendings Fellows Overall Attendings Fellows Overall
( 4 Raters)
( 2 Raters)
( 2 Raters)
14(low) 95 93 97 95/91 97/91 93/91 0.71 0.95 0.68
WMA† 13 83 85 81 89/74 90/77 87/71 0.72 0.90 0.47
LVEDD 15(enlarged)95 95 94 92/87 94/90 91/85 0.67 0.82 0.55
94 94 94 NA NA NA NA NA NA
6 82 86 80 96/79 97/83 95/76 0.76 0.84 0.75
7 90 90 90 85/77 88/79 82/74 0.35 0.59 0.29
IVCsize‡ 12 75 73 77 78/58 81/59 74/57 0.42 0.84 0.39
IVC inferior vena cava; LVEDD left ventricular end-diastolic dimension; NA not available; T TE transthoracic echocardiography; WMA wall-motionabnormality.
* T TE measurements were not visualized on every scan. The first estimate is the proportion of true-positive and true-negative readings among all scans in which the measurement was visualized
(number varies by measurement). The second estimate is the proportion of true-positive and true-negative readings in all patients (n = 97).
† TTE comparison image missing for WMA assessment in 1 patient.
‡ TTE comparison image missing for IVC size assessment in 2 patients.