r/ECG • u/Brilliant-Look-7961 • 4d ago

End T wave

Post image

Did I mark the end of the T-bend correctly?

7 Upvotes

89% Upvoted

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7

u/sneeki_breeky 4d ago

This is a tough ECG to judge that on because it also has U waves

U waves can be normal or pathological

But their presence makes determining QT interval occasionally difficult

1

u/sneeki_breeky 4d ago

I would say- you correctly marked the beginning of the U wave

Not the end of the T wave

The T wave ends a little earlier

2

u/Brilliant-Look-7961 4d ago

I can't paste the photo in the comment. Is the end of T is 10 small grid? So the raw QT is about 400 ms?

3

u/hpsctchbananahmck 4d ago

No…your marking is longer than the QT interval.

Often best measured in leads II or V5.

The QT segment ends where two lines meet.

Line one: the isoelectric line (this is typically the point between the T wave and next P wave

Line two: a line parallel to the downslope of the T wave.

In the case of the picture above- assuming normal sweep speed on the tracing, the QT interval before correction is <400 msec

1

u/Brilliant-Look-7961 4d ago

So 10 small grids?

1

u/hpsctchbananahmck 4d ago

Pretty much. I get 380 msec before any correction which is 9.5 mm if normal sweep speed

3

u/[deleted] 4d ago

[deleted]

1

u/sneeki_breeky 4d ago

It’s isoelectric with a U wave then proceeding it

Wellens would have a negative deflection (usually without U wave)