Atrial Fibrillation (AFib) Support Group
Atrial fibrillation (AF or afib) is an abnormal heart rhythm (cardiac arrhythmia) which involves the two small, upper heart chambers (the atria). Heart beats in a normal heart begin after electricity generated in the atria by the sinoatrial node spread through the heart and cause contraction of the heart muscle and pumping of blood.
This is my GUESS on the basics and limitations of the IPhone/Android Afib app, from the limited info appearing on the web. It may help some of you to decide whether you want to wait for it or get now a portable ecg like the Omron.
You put your finger on the phone camera, and the the app collects the distribution of your heart rate RR intervals (pulse-to-pulse times) over a 2 minutes test time. Same technology of a Finger Pulse Oxymeter.
The app normalizes the RR intervals by subtracting their mean value.
It computes the Root Mean Square of the normalized RR's, hence measuring their spread, i.e. the overall pulse rate irregularity.
It computes the Shannon Entropy of the intervals, hence measuring the unpredictability of the irregularity.
From these 2 numbers it obtains an overall Indicator of Afib, which has unpredictably irregular RR intervals.
Two numbers are returned: Afib Indicator and Average Pulse Rate. Only RR interval (pulse-to-pulse time) info is collected, no waveform data. This is a limitation vs the Omron ecg, that also provides waveform data via ecg traces. My guess is that this is due to basic bandwidth limitation of Oxymetry data collection technology.
You can get useful info from the app:
Whether you are in Afib or most likely in NSR.
If your occasional palpitations are due to Afib or some other irregularity such as PAC's or PVC's, but you can't tell the nature of the irregularity (is it a PAC?). You can with the Omron.
If you have a "regular" tachycardia that is not Afib. Examples are SVT (Supra Ventricular Tachicardia), Sinus Tachycardia, Aflutter with high heart rate. But you can't tell them apart. You can with the Omron. Note that Aflutter without high heart rate (I think it is rare) would look like good NSR, while the Omron should be able to tell them apart.
Summing up the Iphone app would give you good info, the Omron ecg would give a bit more.
But the IPhone app should be cheaper and easier to use. No specialized ecg device, you just put your finger for 2 minutes over the phone camera opening, start the measurement, and get the Afib Indicator and Pulse Rate.
Again all of the above is my guess from limited info, don't take me too seriously.
You put your finger on the phone camera, and the the app collects the distribution of your heart rate RR intervals (pulse-to-pulse times) over a 2 minutes test time. Same technology of a Finger Pulse Oxymeter.
The app normalizes the RR intervals by subtracting their mean value.
It computes the Root Mean Square of the normalized RR's, hence measuring their spread, i.e. the overall pulse rate irregularity.
It computes the Shannon Entropy of the intervals, hence measuring the unpredictability of the irregularity.
From these 2 numbers it obtains an overall Indicator of Afib, which has unpredictably irregular RR intervals.
Two numbers are returned: Afib Indicator and Average Pulse Rate. Only RR interval (pulse-to-pulse time) info is collected, no waveform data. This is a limitation vs the Omron ecg, that also provides waveform data via ecg traces. My guess is that this is due to basic bandwidth limitation of Oxymetry data collection technology.
You can get useful info from the app:
Whether you are in Afib or most likely in NSR.
If your occasional palpitations are due to Afib or some other irregularity such as PAC's or PVC's, but you can't tell the nature of the irregularity (is it a PAC?). You can with the Omron.
If you have a "regular" tachycardia that is not Afib. Examples are SVT (Supra Ventricular Tachicardia), Sinus Tachycardia, Aflutter with high heart rate. But you can't tell them apart. You can with the Omron. Note that Aflutter without high heart rate (I think it is rare) would look like good NSR, while the Omron should be able to tell them apart.
Summing up the Iphone app would give you good info, the Omron ecg would give a bit more.
But the IPhone app should be cheaper and easier to use. No specialized ecg device, you just put your finger for 2 minutes over the phone camera opening, start the measurement, and get the Afib Indicator and Pulse Rate.
Again all of the above is my guess from limited info, don't take me too seriously.
Here is how you work the OMRON Portable ECG:
Press the on button.
Wait a few seconds.
Grasp the unit (like a cell phone size).
Press the unit against your chest (the instructions tell you exactly where) with your index finger on the rounded part with metal conductor. (this is done with one hand (your right hand).
Press start.
Try not to move.
Wait.
When it is ready (it tells you your heart rate and if irregular rhythm), press the "select button" twice.
Sounds harder than it is. It is all done with one hand. Easier than texting.
OR WATCH THIS:
http://www.youtube.com/watch?v=Hk-5SYb3U6k
petey
There is an app called quik heart rate monitor. it works very well for me and I can tell from the display if I am in nsr or other. the priniples are the same as any app where you put your finger over the camera lens. Also I use a couple of other apps to validate readings. All seen pretty accurate.
Finally, I continue to look for devices and apps to capture ekg type data. I still consider buying an ekg machine off ebay.
Robert
PS: ablation 3 coming up I about a month
I agree, the Omron 801 is very easy to use. A minor advantage of the IPhone app is that you'll be able to check for Afib in all social environments, for instance during a business meeting.
I'll definitely keep using the Omron even after the IPhone app is available. The Omron provides more info about your problems via the ecg traces. Also the app identifies Afib by detecting an irregularly irregular rhythm. It would not work for Aflutter where the rhythm is regular. Most of my pre-ablation episodes were Aflutter.
http://www.jfponline.com/pdf%2F5502%2F5502JFP_AppliedEvidence2.pdf
It's nice to know that some low tech solutions are still reliable.
opsyn