Noninvasive measurement of ejection fraction with an iPhone app is possible and very accurate. When this becomes publicly available, it will be a game changer. See this fascinating interview with the lead author.
Why this matters?
Normally I try to cover articles that can change practice immediately. This app is not yet publicly available but is hopefully coming soon. It was so accurate that anyone could measure LV EF anytime they want. It could be like a 6th vital sign along with pulse oximetry. Imagine being able to pull out your phone in a shocky patient and noninvasively measure EF in a matter of seconds.
There's an app for this
This app used the iPhone's unmodified camera to detect hidden oscillations in the carotid artery waveform and mathematically calculate the LV ejection fraction. The gold standard for comparison was cardiac MRI, the most accurate measure of EF. The correlation coefficient was 0.74, which was very strong, as good as 2D echo. This was a pilot study, but it was so fascinating I had to share a glimpse into the future with you. Of note, CHF from diastolic dysfunction would not be apparent with this app.
Noninvasive iPhone Measurement of Left Ventricular Ejection Fraction Using Intrinsic Frequency Methodology. Crit Care Med. 2017 Jul;45(7):1115-1120. doi: 10.1097/CCM.0000000000002459.
Peer reviewed by Thomas Davis, MD.