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24 votes
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ECG wave names origin

Interesting question! I searched briefly and came up with an answer from this short paper. I won't repeat all the details of the paper, but to be not a completely link-only answer I will give a brief ...
Bryan Krause's user avatar
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6 votes

ECG wave names origin

According to this site: http://www.ecglibrary.com/ecghist.html Originally the waves were designated as A,B,C& D but after correction they were termed as P,QRS, T. Why PQRST and not ABCDE? The ...
JM97's user avatar
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5 votes
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Why is the current flow shown to be flowing from the negative area towards the positive area?

By convention, positive current is assumed to be the direction of flow of positive charges. The trouble is that in many common situations (like this one), the current is actually carried by electrons ...
Charles E. Grant's user avatar
3 votes

Can a mathematical function be assigned to ECG diagram?

Yes a function could be assigned to an ECG diagram. I don't know if that would be helpful in any kind of research. Anyway I believe that from a mathematical point of view that if you manage to include ...
serax's user avatar
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3 votes
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Difference between Premature Atrial Contraction and Atrial Fibrillation

Atrial Fibrillation is a dysrhythmia while PAC is an early depolarization coming from the atria. An occasional PAC can be normal for some people. In that case their heart rhythm would be a sinus ...
Gantz 's user avatar
  • 46
2 votes

What does the 'V' stand for in ECG electrode names?

As a paramedic who does EKGs every day, I can tell you it stands for "VECTOR" meaning the direction the electrode monitors electricity from the heart. RA, LA, RL, and LL electrodes are ALL the ...
DFW333's user avatar
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2 votes

How to analyse an ECG?

Beautiful work! Whether the PR is prolonged depends on timescale om x axis (which i cannot find...). I didn't really get the scope of this task. If you are attempting to create a computer automated ...
Adam Robinsson's user avatar
2 votes

How long do the periods of systole and diastole last?

Systole lasts about 3/8 and diastole 5/8 of a cardiac cycle. Keep in mind though that such values vary with heart rate. The higher the heart rate, the shorter the fraction of diastolic time compared ...
user43012's user avatar
2 votes

Is there any case in which excitability increases with lowering the RMP?

A typical voltage-gated sodium channel has 3 gating states: open, closed, and inactivated. The third category is the important one here. Open channels are open: they let ions through. Closed ...
Bryan Krause's user avatar
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2 votes
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In the PR segment of an ECG, how come there's no current flowing?

I'd suggest reading the rest of the Wikipedia article on EKG rather than focusing on the particular cartoon you are using right now, because that cartoon does not depict the dipoles that are measured. ...
Bryan Krause's user avatar
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1 vote

Why are P and T waves curved and not straight (ECG)

P wave represents atrial depolarization (hence atrial contraction). Atrial depolarization takes only a split second, therefore its corresponding wave will be smooth and rounded. Variations from this ...
francesco's user avatar
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1 vote

ECG detection using minimal number of electrodes

First, let's talk about electrodes. Background What do the electrodes measure? When we talk about ECG signals, we generally talk about leads - that is, difference of electrical potential between two ...
sjaustirni's user avatar
1 vote

what is the difference between osciloscope and electrocardiograph?

I would say that electrocardiograph is a specific case of oscilloscope. The main difference, perhaps is that "oscilloscope" is a device for visualization on a display ("scope" from greek "look out"), ...
aaaaa says reinstate Monica's user avatar
1 vote
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why do sodium channels close with excessive extracellular potassium ions in cardiac myocytes?

Short Answer Depolarization block keeps sodium channels in a different state where they aren't available to open. Longer Answer The answer here applies equally to cardiac myocytes and neurons, and ...
Bryan Krause's user avatar
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1 vote

Electrocardiogram: Difference between Atrial Fibrillation and Atrial Flutter

A-Flutter will have discernible waves that can be counted, usually. The R-R interval will be regular or maybe slightly irregular if there's a variable conduction block in the AV Node. A-Fib will ...
DFW333's user avatar
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