Alivecor

[dmac4646]

I must say that I am getting pretty frustrated with it - I don't use it a lot but almost always it is now unclassified readings - yet when I pay the £5 for analysis it comes back normal ( thankfully) - anyone else have this problem ?

[Finvola]

The only time I get unclassified readings is when I have several ectopics in a 30 second trace. Setting for a longer trace usually gets a normal report.

[booboo73]

Anything under 50bpm I get unclassified x

[PeterWh]

FYI - I am in persistent AF. I have an iPhone 5S and I have the specific AliveCor in iPhone 5S holder permanently attached to the phone.

I agree that setting a longer time (I use 2 minutes) is key. Also making sure there are no extermnal influences (ie manily noise) because the AliveCor used the phone microphone. probably exacerbated if you don't use a specific case and hold it close to your device. Key is to hold AliveCor it STEDAY as close as you can to your smart phone or tablet.

A few months after buying my AliveCor I did a number of readings suing all the different timescales (30 secs, 1, 2, 3, 4, 5 mins). Because I took the ECG at the different times you can not compare exactly the ones for say 1 minute with that for two minutes because I am in persistent AF they are different.

I then compared the graphs and for instance compared the HR for all 1 to 5 mins for the first minute. Then looked at 2 to 5 minutes over 2 minutes. Then I looked at averages for each time over each whole minute (ie for the 5 minute one I looked at HR for 0 to 1 min; then 1 to 2 mins; then 2 to 3 mins; etc.

From this I concluded that the optimum time for me was to set the time duration at 2 minutes and then this gives a truer baseline HR from reading to reading, day to day to make comparisons much more meaningful. This also reduced the errors and false readings (18 months ago they did not have the same classifications as now).

One thing that I started doing a months ago was to write into the notes feature what the minimum and the maximum rate that is shown on the screen as I am taking the reading. This has produces some interesting results, probably because I am in persistent AF). So for instance the 2 min average was 88 but the minimum average during the reading was 81 and the highest average was 106. I have yet to do an analysis to see patterns.

Another thing that I have found is that if my AF is "more" active this generates an unclassified analysis on the device but if I repeat the test a few minutes later when my heart has calmed down a bit the analysis shows up as AF (which in theory it always should). This could either be because of ectopics or the AF is firing away in the veins.

I have noticed that often the first 5 seconds is erratic (ie a settling down period). If someone has a 10 second burst of ectopics during a 30 second recording that would represent 33% of the total time and that in itself could (because of the programming ranges) lead to an unclassified reading. However that 10 second run only represents 8% of a 2 minute recording.

Also watch out for external interference. It can be simple things like sitting too close to a computer, TV, radio, music, etc, running water, etc (I have proved al those). However it usually is a specific rather than general (with the exception of the computer). So for instance it can be the specific sound from the TV at the time of the reading, not the TV itself.

I have also turned off the newish feature of voice recording and I type my notes in.

[jan-ran in reply to PeterWh]

Just a thought for those who have an alivecor that doesn't fit your phone. Mine fitted iPhone 4, now I have a 5. To ascertain steadiness, I just rest my phone on top of the device with my fingers underneath as usual, resting on the table. Jan.

[dmac4646]

60/68