• support@fourthfrontier.com
  • Profile picture of Robbie_tar

    Robbie_tar

    3 years, 7 months ago

    Good morning all,
    I am a new owner/user of the Frontier X and as a data nut, I am very enthused about it so far.
    I’m a 78 year old male with frequent PVC’s that do not seem to cause any issues.
    I’ve had 4 Stress tests since 2012 and all after the first have been clean.
    My Cardioligist has offered bata blockers but I have declined.
    My resting HR is ~ 50 and my 2 minute HRR is somewhere around 40 beats.
    I hope to use the Frontier X to gather information and keep track of the PVC-s for any changes as well as the other info that the device provides.

    My one question concerns QTc.
    Mine seem to all be reporting higher than I expect from previous research.
    I have attached a screen clip of a recent report.
    I have chosen a period where the HR is 60 just to eliminate any confusion about the correction formula, but applying the Bazett formula to many other points with HR as high as 130, they all show the same level over what I expect to see.
    The attached shows a QTc of 511 at a HR of 60.
    Counting small squares from any of the normal traces shown, I come up with 10 Small Squares or 440.
    (The odd trace is a PVC)
    Can anyone help me understand where I may be wrong in my thinking?
    Thanks for any help you can give.
    Its been interesting and informative reading through the posts.

    QTc Question 1.jpg
    334.17 KB
    Download
    1 Comment
    • Hello, I’m a retired cardiovascular safety pharmacologist. You are not wrong in your thinking, but exactly correct. The upper trace is, as you note, at a cycle length of ~ 1 sec (970 ms to be exact). The associated QT for the first and second beats on the upper trace are 433 ms each, exactly as you measured. You shouldn’t include beats associated with arrhythmias. Make sure to choose beats preceded by several seconds of normal sinus rhythm. I see no data on these traces that support a QT of 511 ms. Perhaps the folks at First Frontier can further explain the results to you. /Hank

Media