5555555 (X) Feb 6, 2017:

Phase 0 Phase 0 is a very important clinical indicator. This is a fast depolarization of the cardiac muscles due to fast influx of sodium ions into the cells upon opening of the sodium channels.

Clinical significance of Phase 0 lies in the fact that it interferes with normal transmural depolarization and, thus it is arrhythmogenic.

When we look at QRS complex, we pay attention to J waves, notches, and slurs of the R slope. In addition, we look at the epsilon wave at the end of QRS that is significant of arrhythmogenic right ventricular dysplasia (ARVD).

This happens when action potential that moves from endo to epicardium is slowed down by Phase 0, which is originated by the myocardium isolated by the fatty tissue of by the fibrosis due to cardiomyopathy.

Phase 0 depolarization abnormalities that occur with the initial wave of activation include bundle branch blocks, myocardium damage or abnormalities and intraventicular delays. These can be due to electrical disturbances, myocardial hypertrophy, dilatation, damage or infiltrative disease.

This phase can be detected through the examination of the QRS complex.

Evgeni Kushch Feb 6, 2017:

Коллеги, я все равно не верю, что здесь фаза 0 :-) Здесь очевиден вполне перечень интервалов и в русском языке вряд ли стали бы сокращать фазу до такого вида, даже если бы использовали такой показатель. Фаза 0 — это всего лишь электрофизиологическая подоплека формирования комплекса QRS ЭКГ, но не используется в клиническом описании, как и, например, фаза плато, вход ионов и пр.

Вот например, еще описание краткого интервала QP:

There are 2 types of inverted P waves; the one is wider and more plump with almost fixed QP interval of 0.10 second (PB), and the other is rather diphasic with narrower downward deflection with variable PQ or QP interval (Pc). P7 and P12 which are of similar configuration to them, follow the QRS complexes with fixed QP intervals of 0.11 second, while P11 and P13 have the different contour and unfixed time relationship to QRS complexes.

https://www.jstage.jst.go.jp/article/ihj1960/3/3/3_3_284/_pd...

Хотя бы комментарий оставить нужно в переводе.

5555555 (X) Feb 3, 2017:

There is a possibility of PVC's (premature ventricular contractions). They usually don't happen in every beat, but once in a while. There is often a compensation period after a PVC. During PVC's peaks can come together very closely, almost juxtapose.

So if PVC's are mentioned in the source, then there is a possibility of a short QP intervals. They are mostly irregular. I apologize, no time to read the articles right now :).

Evgeni Kushch Feb 3, 2017:

Colleagues, look here as well (note figures also):

http://obmendoc.ru/files/users/andrey/80/view/285478-285525

- НЖТ с узкими комплексами QRS;
- ЧСС - 150-220 мин., чаще 180-200 мин.;
- зубец Р наслаивается на комплекс QRS или следует сразу после него ( QP < 0,09 с.);
- начинается и прекращается внезапно.

http://intranet.tdmu.edu.ua/data/kafedra/internal/nev_stan/c...

PQ длиннее QP, QP>70мс

http://docfv.narod.ru/ARCHIV/ECG_PED.htm

http://www.findpatent.ru/patent/255/2558973.html

And here:

https://www.health-ua.org/mc/kardiologiya/240/74/

Добрый день, подскажите, пожалуйста, что означает написанное в ЭКГ: Изменения по типу гипоксии в нижне-боковой стенке ЛЖ. Синусовый ритм нерегулярный с ЧСС 71-88 уд в минуту. PQ - 0,12 QP - 0,10 QT - 0,16 (не точно, цифры непонятно написаны) R-R 0,68-0,84 P - 0,10 Эл. ось не отклонена, вертикальная. Есть ли проблемы с сердцем? Мне предстоит операция под наркозом.

5555555 (X) Feb 3, 2017:

Yes, Eugene, there may be a very bad text quality. It just looks like the other values went through fine. Obviously, OP or QP cannot be the same as QRS. But I am trying to base my line of thought on clinical significance and what we do see here.

QRS complex is used to measure Phase 0, and it lies between 0.08 and 0.099. Phase 0 is a useful parameter for such abnormalities as bundle branch blocks, damage to the myocardium, and intraventricular delays.

Since the other values seem to match the normal ranges, I assume that 0.09 may be also clearly printed in the document. In which case QRS complex and the rapid depolarization phase make sense.

But, who knows. We don't have the source.

Evgeni Kushch Feb 3, 2017:

Kimberly, I am mentioning it because I am not sure if figures were OCR'ed/typed/written correctly as well (what if there for example could be 0.99 or 0.89 or 0.69). At the same time, PR, QRS and QT are quite distinct intervals to overlook them here...

Here QP is mentioned as well:

http://naukarus.com/novye-vozmozhnosti-ekg-pri-otsenke-reabi...

5555555 (X) Feb 3, 2017:

Eugene, I am afraid, it can't be a QP simply because the duration the interval in question is too short. It's only 0.09 sec. I thought about it, but it can't apply here.

Evgeni Kushch Feb 3, 2017:

QP is used very rare as far as I know, commonly for scientific and experimental purposes, I don't know it to be of importance in clinics.

It is an interval between Q and P waves

See here for example:

http://research.ijcaonline.org/volume33/number8/pxc3875979.p...

Olga and Igor Lukyanov (asker) Feb 3, 2017:

You both may be right but I cannot find the OP equivalent

Evgeni Kushch Feb 3, 2017:

There should be a problem with OCR

5555555 (X) Feb 3, 2017:

Could it be a poor resolution of the source scan? And it's Q instead of O?

Normal resting QT is 0.40 for women and 0.44 for men.
PQ is sometimes used instead of PR, and its normal resting value is between 0.12 and 0.20.
OP is puzzling. The normal value for QRS is about 0.09