holter calculated Qtc ... Wrong?

[LittleRamona]

Hi everyone.
Recently i had a holter monitor cause my constant palpitations and tachycardia.
Besides some pvs and pacs (which The Dr said were causing my symptoms) i noticed in The report, in The QT chart, a max qt 436, max qtc 476, with heart rate 62.  The % of max. Above 450 Qtc was 11.4%.
When asking my gp about that he took a calculator and with The info in The chart calculated The qtc and said the report was wrong and The max qtc was 443 ( wich i have read is long -=<440 ms-)
My question is, if this is posible, The report calculating it wrong. And what about The % number? Is The same but for a meassure of 443 ms?
Thanks for anyone who can help me

[alejandradr]

After some research i think used a formula called Bazzet to calculate The qtc.
Qtc=qt/√RR. RR=60/HR
A calculated and it was indeed 443 ms

[LittleRamona]

Thanks for your answer.
The Dr recalculated The qtc only whit The info i gave above: The qt and The heart rate.  At any moment he looked at The ekgs strips.

[Artaud]

After some searching on a topic I know nothing about, I found the following, which may explain your situation.

"The reliability of QT interval measurements may depend on the shape of the T wave......During 24 hour Holter ECG recordings, inaccuracies of the automatic measurements due to changes in T wave morphology....."

What made you ask to begin with? I'm not knowledgeable on this topic, but with a 24 hour holter, you may have had 100,000 heart beats or more. It seems to me that the doctor could calculate based only on the tiniest of sample of your EKG.

Maybe someone accustomed to this process would contribute, but I earnestly was curious to see if I could find an answer to a segment of your question, which I hopefully have.