Talk:Electrocardiography

Talking about QT_c, how about providing the references to Bazett's and Rautaharju's publications???
JFW | T@lk 11:15, 7 May 2004 (UTC)

Wilson's central terminal

I have added this sentence in brackets, as I did not understand the purpose of Wilson's central terminal was.

(recall that Wilson's central terminal is the average of the four limb leads. This will approximate ground)

I am only a lowly first year medical student, so if it is wrong, please correct it. M0rt (talk) 07:49, 13 May 2009 (UTC)

question

I didn't understand what is the "lead". Does it have anything to do with the chemical element?--132.66.16.12 08:44, 26 Aug 2004 (UTC)

A lead (rhymes with speed) is a recording electrode which measures voltage at a particular point in the body. It's not related to the chemical element, lead (rhymes with Fred). In EKG and related techniques, usually between 5-12 leads are placed on the limbs and ankles, and are used to record a profile of the electrical activity of the heart. --Diberri | Talk 14:49, Aug 26, 2004 (UTC)

In (probably) simpler words, a lead is a PAIR of electrodes, & any electrical disturbance created by the activity of the heart has to "do work" against the potential difference existing between the 2 electrodes. It is not explained in the article, but the electrodes function as if acting from the points of attachment of the limb to the body. Even though potential difference is a scalar, the leads have a direction. For instance, in lead I, the the electrode attached to the left upper limb is it at a higher potential than the opposite arm, so a positive electrical disturbance (generated from the heart) will have to do positive work in travelling from the left to the right side. Hence, this will be registered as a positive deflection. KC Panchal 11:10, 5 February 2007 (UTC)

Why do vawes start with the letter "P"? Why it does not start with, for example, "A"? Why does zero degree of the axis in frontal projection place at "03.00"?Simonnanlohy 17:28, 30 July 2007 (UTC)

J. Willis Hurst, MD, "Naming of the Waves in the ECG, With a Brief Account of Their Genesis," Circulation 1998;98:1937-1942

A zero degree axis in the frontal plane correlates to 3 o'clock by convention. Since the normal axis runs in a right shoulder to left leg direction, the normal quadrant (or left inferior quadrant) is 0 - 90 degrees (although it can extend leftward to (-30) and still be a normal variant). There is no other reason that I am aware of. MoodyGroove 18:43, 30 July 2007 (UTC)MoodyGroove

Requested move

move to electrocardiography?

like electroencephalography - Omegatron 18:20, Apr 19, 2005 (UTC)

That sounds like the right thing to do. Jonas Olson 21:49, 22 Apr 2005 (UTC)

It IS the right thing to do. Then there could be a discussion of invasive electrocardiography, which is an important procedure these days. Lou Sander 15:29, 14 January 2007 (UTC)

It's okay with me. MoodyGroove 00:47, 16 January 2007 (UTC)MoodyGroove

This definitely should be moved "To be consistent with EEG, EMG, EOG, ERG and any others. --83.146.15.165" (from Wikipedia:Requested moves). Since the discussion has been open for 4 years with no opposition, it should be non-controversial. Therefore, involvement of Wikipedia:Requested moves is not really necessary, and I added {{db-move}} to electrocardiography. --Scott Alter 01:11, 13 March 2009 (UTC)

jargon

"through the interventricular septum. Very wide and deep Q waves do not have a septal origin, but indicate myocardial infarction."

all these medical words (all over the article) need either linking or explanatory text in the article itself, for us laymen. - Omegatron 18:30, Apr 19, 2005 (UTC)

The Q-wave normally indicates the phase during which the septum depolarises. However, a similar change (but much more pronounced) is seen in the hours after the onset of a heart attack. JFW | T@lk 10:24, 20 Apr 2005 (UTC)

EKG-ECG

I've heard that electrocardiogram (ECG) is pronounced EKG so it would be easier to differentiate from EEG in speech, it's also phonetic, not because cardio- starts with K in german Prometheus235 14:27, 14 Jun 2005 (UTC)

Agree. Bart 12:29, 9 October 2007 (UTC)

This practice of pronouncing ECG as "EKG" is an American idiosyncrasy, not used where British English is spoken. NRPanikker (talk) 00:47, 13 June 2008 (UTC)

Einthoven article

The article on Willem Einthoven (Nobel Prize winner for his EKG work) is currently quite stubby. Could someone with expertise in this area expand his article a bit? Sayeth 21:21, 6 February 2006 (UTC)

Figure

The figure [[1]] labels the PQ segment as a PR segment. —Preceding unsigned comment added by 194.171.252.100 (talk • contribs) 19 Sep 2006

My understanding: The QRS complex may have one of Q, R, or S, or a combination or even another R (r'), but the segment is always called "PR" by convention. A-giau 09:53, 29 September 2006 (UTC)

That is correct. PR is used by convention because not all QRS complexes have a Q wave. Granted, not all QRS complexes have an R wave, but such complexes are generally labeled QS complexes, and the PR interval is the PQ interval. MoodyGroove 22:34, 22 January 2007 (UTC)MoodyGroove

ECG as Security Device

I am reading Fundamental Accounting Principles (18 edition, Wild, Larson, Chiapetta, www.mhhe.com/wildFAP18e McGraw-Hill Irwin) and on page 314 it says "There's a new security device -- a person's ECG (electrocardiogram) reading -- that is as unique as a fingerprint and a lot harder to lose or steal than a PIN. ECGs can be read through fingertip touches. An ECG also shows that a living person is actually there, whereas fingerprint and facial recognition software can be fooled." It would be interesting to add this information to the article, and if anyone has any more information reguarding this. I'm not sure how to reference it or where to put it, so if someone else could do it, that would work.

Sounds like a bit of a tall story to me. --John24601 11:49, 23 November 2006 (UTC)

Anything intended to be used as a personal identity mark has to be unique (which your source claims the ECG to be, but is hard to digest), but more than that, it has to be REPRODUCIBLE, which ECG, most certainly, is not. That's because, the tracing keeps on changing not just from minute-to-minute, but even with something as simple as breathing in (heart rate increases) or breathing out. So, I totally agree with John. KC Panchal 11:17, 5 February 2007 (UTC)

It is true that an EKG is probably better than a fingerprint in a given individual especially if they have a electrical birthmark (most folks do). Variability in lead placement would probably negate the admissability of this evidence in a court of law. Limb leads only may narrow the agreed upon signature. Invasive EP data seals the identity beyond question.--Lbeben (talk) 02:23, 8 August 2008 (UTC)

History

Oxford DNB credits Alexander Muirhead with using an electrocardiogram as early as 1872. I've credited him with this 'first' though others exploited it. Ephebi 16:10, 27 November 2006 (UTC)

There have been many developments in instrumentation, and they are not covered here at all. Today's ECG machines often provide computerized interpretation, for example. Lou Sander 13:30, 26 March 2007 (UTC)

Yes they do. In fact, the GE-Marquette 12SL ECG interpretive algorithm is the industry standard. It has an excellent specificity for acute myocardial infarction. MoodyGroove 02:30, 14 April 2007 (UTC)MoodyGroove

Pictures

Could we please get an image of an electrocardiograph from after a hundred years ago? I don't want people thinking doctors still use EK graphs that look like they were commissioned to be built by the tsar. VolatileChemical 10:55, 3 January 2007 (UTC)

Posterior Leads

Discussion of posterior leads needed.

There is a discussion of posterior leads in the electrocardiogram section.MoodyGroove 15:12, 14 February 2007 (UTC)MoodyGroove

I'm sorry, I got this confused with the myocardial infarction article. There is a discussion of posterior leads under the electrocardiogram section of the myocardial infarction article. I'm not sure whether or not this article would benefit from a discussion of posterior leads, since it's a rather obscure tactic for detecting myocardial ischemia in the distribution of the circumflex artery. At it stands right now, I'm okay with it being in the myocardial infarction article. If we're going to go that far here, then there are a great many other things that need to be included, and it seems to me that this article should be a general overview of electrocariography. That's not to say I would fight someone if they wrote a section for non-conventional leads, I just don't know that it's necessary for this article. MoodyGroove 17:23, 14 February 2007 (UTC)MoodyGroove

Gd afternoon sir,

---

What is the different between physical examination and clinical laboratory  ?

   < Physical examination : body temp.  , BP , 

   clinical laboratory : ECG , blood clotting  >

In physical examination , body temp. have to be used termometer , Blood pressure have to be used Sphygmomanometer .

Both of them are used equipment to approach. So i think that they should be grouped in the clinical laboratory such like ECG and blood clotting. But why they are grouped in Physical exam ?

thank you ,

protrude from sulcus limitans , k_pinyosamosorn@hotmail.com

Image:ECG Vector.svg

Hi, the above named image from this article needs to be changed as there is a slight mistake. The second arrow down is pointing the wrong way, so is identical to the diagram above it. The negative deflection on the ECG should be represented by current moving away from a positive electrode. Thanks. Djsilverspoon 16:01, 3 April 2007 (UTC)

Previous version of the image has been restored due to unintentional error in .svg image. MoodyGroove 02:26, 14 April 2007 (UTC)MoodyGroove

ST interval

I removed this section from the article:

The ST interval comprises the ST segment and the T wave. The fetal ST interval may be analyzed during labor (ST analysis) to identify fetuses at risk for asphyxia. Changes in the ST segment and increased T wave height (in relation to the QRS complex) are indications of fetuses at risk.

In my opinion, this gives the concept of an 'ST interval' undue weight. It's an obscure, minority concept in electrocardiography, and not particularly notable. I've heard it referred to as the JT interval (J point to end of the T wave) which is a more precise description. The JT interval is used to estimate the QTc for patients with a baseline intraventricular conduction defect. But no one talks about an ST interval (or JT interval) in common practice. I'd like to see more references to prove this measurement is notable. MoodyGroove 20:31, 10 April 2007 (UTC)MoodyGroove

Deploarisation wavefront and postivive electrode diagram

Should the middle image in this diagram not feature the depolarisation moving away from the positive electrode to cause a negatively deflected wave? richard —The preceding unsigned comment was added by 81.129.83.203 (talk) 09:35, 13 April 2007 (UTC).

Yes it should. The old version of the image is correct. MoodyGroove 15:07, 13 April 2007 (UTC)MoodyGroove

The old image has been restored until such time as the .svg image is corrected. MoodyGroove 02:27, 14 April 2007 (UTC)MoodyGroove

article assessment

I would like to suggest that this article be assessed by an expert for Good Article status. (Reason that I am not adding this directly to WP:GA/N is that I specifically request that the evaluation be done by an expert.) 69.140.164.142 04:48, 19 April 2007 (UTC)

ECG innovation and ETG

While working with the Electrotridoshagraphy technology [2], which is an Ayurvedic whole body scan and is also used for status quantification of the Ayurvedic basic principles, the inventer of the ETG technology Dr. Desh Bandhu Bajpai have innovated presently ECG machine, which is an advance level achievement of the Electrocardiography. Conventional ECG machine can diagnose whether the sick person is suffering from cardiac disorders or not. But this innovative machine [3]is able to diagnose, if the complaints are due to Thyroid, pulmonary circulation, Muscular or neurogical problems, epigastritis, Pancreatitis, renal problems etc. user:debbe,28 April 2007,11:19 PM IST.

Unfortunately, you cannot reference your own blog for such extraordinary claims. As I noted on your talk page, it appears as though you have a direct conflict of interest concerning this device, and even if you didn't, your claims would need to be appropriately sourced because original research is not allowed on the Wikipedia. Good luck! MoodyGroove 17:56, 28 April 2007 (UTC)MoodyGroove

Who makes treatment decisions

I removed this comment from the article:

Due to the inherent subtleties in interpretation only paramedics and qualified physicians should make treatment decisions based on rhythm analysis.

This is inflammatory, and it simply isn't true. MoodyGroove 21:47, 2 May 2007 (UTC)MoodyGroove

confusing

Moved this section to the bottom of talk page per talk page guidelines. MoodyGroove 02:42, 5 May 2007 (UTC)MoodyGroove

This whole page is confusing except for the history! And I'm a brand new med student too... —Preceding unsigned comment added by Flashpoint145 (talk • contribs) 23:19, 11 April 2007

I don't find it confusing at all. I'm removing the tag until you can give a more detailed explanation of what the problem is. Saying the "whole page except for the history" is confusing isn't helpful. It also isn't reasonable. In my opinion, useless tags do nothing but clutter up the Wikipedia. It's better to light one candle than curse the darkness. MoodyGroove 15:15, 13 April 2007 (UTC)MoodyGroove

Why don't YOU find it confusing? Because you thoroughly understand the topic? I've always thought of Wikipedia to be a great source of education. It is difficult to learn something if you do not understand what is being said. If the medical terms and jargon were to be dumbed down to a middle or high school level, the article would be much easier for the general public to comprehend. Imagine a middle school student having to do a science project on EKG's. Would that student find this article easy to read? Put yourself in the shoes of others. What I'm trying to say here is that the wording of the article is too technical and needs to be fixed in such a way that the article can be understood by people outside of the medical field. With that said, I'm re-tagging the article due to the vocabulary and terminology in these sections:

1) Precordial

2) Ground

3) Entire section on Waves & Intervals

4) Clinical Lead Groups

Flashpoint145 18:32, 4 May 2007 (UTC)

I do thoroughly understand the topic, Flashpoint145. But that's after 10 years of study, which included many different books, dozens of journal artilces, and hundreds of real life case studies. I don't think it's reasonable to expect that a middle school (or high school) student should be able to grasp a topic this technical from reading one encyclopedia article. Most textbooks on electrocardiography are hundreds of pages long, with dozens upon dozens (if not hundreds) of example ECGs. I actually think this article gives a decent overview, all things considered. It's just been rated B-class on the assessment scale, and it's well on its way to being a good article, in my opinion. It could be expanded a bit (axis will need to be a separate article), but certain topics are sufficiently technical that they will contain a certain amount of esoteric terminology (certainly many medical and computer articles will be this way). A review of your contributions suggests that you tag a lot of articles for being confusing.[4][5][6][7][8][9] I don't necessarily have a problem with that, if that's how you choose to contribute to the Wikipedia, but I think you yourself might benefit from putting yourself in the shoes of the editors who create content. I still don't think tagging the entire article is reasonable, but I will defer to the judgment of other editors in this matter. I'd actually prefer the "too technical for a general audience" tag to the "some readers may find this confusing" tag. You can't always help what some readers find confusing. MoodyGroove 02:32, 5 May 2007 (UTC)MoodyGroove

I do appreciate it. Confusing may have been the wrong word and technical may have been the correct one. Thank you.

72.40.44.83 11:02, 5 May 2007 (UTC)

You're welcome. I placed the history section up near the top per suggestion from article assessment and changed the "confusing" tag to the "technical" tag (starting at the graph paper section) pending further comments from other editors who may wish to comment. Best, MoodyGroove 17:12, 5 May 2007 (UTC)MoodyGroove

The section on "axis" is confusing.

69.140.164.142 05:24, 19 April 2007 (UTC)

I'll grant you that. It's a difficult topic, even for medical students. I started the hexaxial reference system article (very stubby) to help explain it, but it needs a lot of work. MoodyGroove 21:13, 19 April 2007 (UTC)MoodyGroove

My question is: What is the significance of the elevated and depressed ST segment? Apparently it refers to a myocardial infarction, and that seems to be a leading cause of cardiac related death - so should it not have its own sub-heading and discussion? Nitric Oxide 19:32, 14 August 2007 (UTC)

It may or may not refer to myocardial infarction, but the significance of ST segment elevation is explored fully in the electrocardiogram section of the myocardial infarction article. MoodyGroove 19:59, 14 August 2007 (UTC)MoodyGroove

Language is too technical

I was reading the chapter in Harrison's on electrocardiography and I wanted to review it in an article on the level of the general reader (which is what Wikipedia is supposed to be).

This entry has a lot of interesting background, particularly the history, but it's pretty difficult reading, for all the reasons people have already given.

I think of a prototypical reader of Wikipedia as a technical person who may not know much about medicine but who just had a diagnosis of heart disease and wanted to understand his EKG. Or it could be an intelligent high school student (or anybody) who's curious. Such a person couldn't understand this article.

For example, if I didn't know what a depolarization vector was, I couldn't figure it out from reading this article. The sections on the limb leads and precordial leads don't clearly explain what the purpose of those leads are (to identify the direction of the vector in the frontal and horizontal plane, respectively, as Harrison's explained it).

The curious thing about this article is that it starts off to explain something, and then goes off on a digression. The section on limb leads starts to explain what they are, and then goes off about Einthoven's buckets of salt water. I realize this is interesting to you (and to me), but an ordinary reader can't follow this if you keep interrupting with historical footnotes.

Richard Feynmann (and others) said that, if you can't explain something to a 12-year-old, you don't understand it yourself. An intelligent high school science student could get through the Harrison's chapter. And there's the idiot's guide to EKGs, Dale Durbin's "Rapid Interpretation of EKG's". It's not an inherently difficult subject. Nbauman (talk) 00:54, 20 January 2008 (UTC)

Introduction

(I'm moving this from my user page.)

Hi. With regard to your recent edits, the heart does not create electrical waves when it pumps. Rather, it pumps in response to the electrical waves it creates. It is electrodes that are connected to the skin. The electrocardiogram does not give information about the strength or weakness of cardiac muscle. The fascicles in the electrical conduction system are not nerves. I would not substitute the word 'salt' for 'electrolyte' and potassium is more important than calcium. As a stand alone comment, it is false that the ECG measures the pumping action of the heart. Overall, with regret, I would have to say that you did more harm than good to the article. I would prefer that you revert the changes, post your changes to the talk pages, and take comments. The lede simply isn't accurate anymore. It needs to be as simple as possible, but not more so. Best, MoodyGroove (talk) 03:35, 22 January 2008 (UTC)MoodyGroove

OK, thanks for your comments. Let's work on this.

But first I'll remind you of what the Nobel laureate Francois Jacob said: "In describing genetic mechanisms, there is a choice between being inexact and incomprehensible." Or, as Sven Gard rephrased it, "as inexact as conscience permits." Nobel I'll also remind you of a review in Science of Al Gore's "An Inconvenient Truth." The reviewer said that (while it was basically accurate) "we scientists" wouldn't have oversimplified it like that, "we scientists" have been trying unsuccessfully to get the public's attention for 10 years, until Gore produced an award-winning movie that educated millions of people.

I want to break up your comments into separate headings, so we can discuss them one at a time. I've interviewed hundreds of doctors for publication, and we go through a negotiating process. The statements have to be accurate, but they also have to be comprehensible to a layman. (I enjoy this process, because it helps me understand things accurately.) It's not a reasonable objection to say, "That's true, but it doesn't give additional important facts."

There's a balance between accuracy and comprehensiveness, OTOH, and clarity and simplicity OTOH. Clarity and simplicity is most important in the introduction. You simplify in the introduction, and explain in more precise detail later.

One of the typical readers that I imagine is a sysadmin with a degree in computer science who just got back from the doctor after a heart attack and a copy of his ECG, and wants to figure it out. (Like Andrew Grove with his prostate cancer.)

It's certainly possible to describe an ECG to an intelligent, science-literate layman -- as in for example the Merck Manual, or Harrison's, or Dale Dubin's Rapid Interpretation of EKG's, or in Anaesthetist.com which is linked in the article. I've already quoted Richard Feynmann. It can be done.

So you can object if it's not accurate, but I can object if a layman can't understand it. These goals can almost always be resolved, at least for an introductory article in medicine.

Agreed? Nbauman (talk) 17:23, 22 January 2008 (UTC)

Creating electrical waves

I wrote: The heart muscles create electrical waves when they pump.

You wrote: the heart does not create electrical waves when it pumps. Rather, it pumps in response to the electrical waves it creates.

Harrison's 16th ed., p. 1311 says, "The electric currents that spread through the heart are produced by three components: cardiac pacemaker cells, specialized conduction tissue, and the heart muscle itself. The ECG, however, records only the depolarization (stimulation) and repolarization (recovery) potentials generated by the atrial and ventricular myocardium."

So in my reading, Harrison's says that "the heart muscle itself" (along with the pacemaker and conduction tissue) produces electrical waves. Correct? Nbauman (talk) 17:23, 22 January 2008 (UTC)

Electrodes

I wrote: These waves pass through the body and can be measured by wires attached to the skin.

You wrote: It is electrodes that are connected to the skin.

Electrodes are wires, right? We agree there, don't we?

(I used the simpler word "wires" rather than "electrodes" because a reader in talk didn't understand the meaning of the word "lead". I've been surprised at how even intelligent, educated people who have learned about their disease didn't understand what I would think are simple medical terms.)

Information about cardiac muscles

I wrote: Wires [electrodes] on different sides of the heart measure the activity of different muscles.

OK?

I wrote: An ECG displays the voltage of these wires, and the muscle activity that they measure from different directions.

I wrote: This display indicates the overall rhythm of the heart,

OK?

I wrote: and weaknesses in different muscles.

You wrote: The electrocardiogram does not give information about the strength or weakness of cardiac muscle.

I'm looking at figure 210-11 in Harrison's (to use a source that is easily accessable to both of us). It shows how the ST elevation is changed when a muscle is injured by ischemia. When a muscle is injured, it's weaker.

That's what I was referring to.

On the basis of that statement in Harrison's, isn't it accurate to say that the ECG gives information about the injury of muscles?

Is it therefore accurate to say that it gives information about the strength or weakness of muscle? Nbauman (talk) 17:23, 22 January 2008 (UTC)

Conduction

I wrote: It is the best way to measure and diagnose abnormal rhythms of the heart[1],

OK?

I wrote: particularly abnormal rhythms caused by damage to the nerves that carry electrical signals

You wrote: The fascicles in the electrical conduction system are not nerves.

You're right. My references keep referring to "conduction tissue," and I conceptualized them as nerves. But they never say "nerves."Thanks for the correction. Nbauman (talk)

Electrolytes

I wrote: or abnormal rhythms caused by levels of salts, such as calcium, that are too high or low.[2]

You wrote: I would not substitute the word 'salt' for 'electrolyte'

Why not? The rule in Wikipedia is that we're writing for ordinary people, not experts (although I personally don't mind writing more difficult material further down in the article). People who have trouble with the meaning of the word "lead" are going to have trouble with the word "electrolyte". I remember a BMJ essay in which a doctor described how a patient dropped a term that he hadn't used since medical school, and he had to stop and think about what it meant.

The people who edited the Merck Manual into the layman's edition did studies and found that laymen like to learn the technical terms, and so they gave the technical terms accompanied by definitions in layman's terms. But you can't do that in the introduction.

The more technical terms you put into an introduction, the the more people will find it incomprehensible. And it only takes one technical term in the introduction to make people give up on the whole article.

We could say, "salts (electrolytes)," but even that would impair readability, the way the climate scientists lost their audience when they tried to be more precise.

You wrote: and potassium is more important than calcium.

OK. I was just using an example. We can substitute potassium if you like. But if we list every electrolyte in the introduction, we lose readability.

Identify damaged muscles

I wrote: In myocardial infarction (MI), the ECG can often identify the heart muscles that are damaged, but it's not sensitive enough to rule out certain kinds of damage.[3]

OK?

Measuring pumping

I wrote: The ECG can also measure the pumping ability of the heart, although ultrasound is more accurate.[4]

You wrote: As a stand alone comment, it is false that the ECG measures the pumping action of the heart.

That was my rewrite from the earlier version of the article, which said:

The electrocardiogram does not directly assess the contractility of the heart. However, it can give a rough indication of increased or decreased contractility.[4]

[4], the Am J Med. 1989 [!] article, says:

CONCLUSION: Thus, an entirely normal result on a resting 12-lead electrocardiogram in patients with suspected coronary disease but no history of a previous myocardial infarction is a reliable (95%) predictor of normal left ventricular function.

I don't know enough about this to comment. I can't recall what I read about this in other sources. Could you clarify what it means by "contractility"? I was just trying to include as much of the original content as possible in my edit. Unless it's important, it doesn't belong in the introduction.

Improving the lead

You wrote: Overall, with regret, I would have to say that you did more harm than good to the article. I would prefer that you revert the changes, post your changes to the talk pages, and take comments. The lede simply isn't accurate anymore. It needs to be as simple as possible, but not more so. Best, MoodyGroove (talk) 03:35, 22 January 2008 (UTC)MoodyGroove

It is often traumatic for a writer to see his beloved words edited. But there is no point to writing about medicine if your target audience can't understand what you're writing. In Wikipedia, your target audience is the ordinary reader, not the specialist. For this article, there is clear documentation in Talk that Wikipedia readers can't understand what you're writing. For a writer, this is a problem.

It's even a problem to a doctor if a patient can't explain what he's saying. (I have a citation somewhere of a baby who died because its mother didn't understand the doctor's instructions to "push fluids". He used a technical term rather than an ordinary term that his patient would understand.)

I once met Stephen Petranek, the editor of Discover. He said that when he took the magazine over, it was unreadable (and losing money). He couldn't get through some of the stories himself. He had to make it readable -- what he called "super-readable".

This article is unreadable. I rewrote the original lede because it was unreadable. (Interestingly, there are studies which found that bulleted points are harder to understand than a well-written paragraph. I used a lot of bulleted points before I saw that, and that was in the days before PowerPoint.) An editor once kicked a story back at me and said, "Rewrite this. Don't touch it up. Rewrite it from the beginning."

And that, with regret, is what I would say about this lede, if you want to meet the Wikipedia standard of being understandable by the general reader. You can go through the original lede in Talk and rewrite it point by point, or you can go through my lede in Talk and rewrite it point by point, or you can do both. But that original lede needs a chain saw, not a scalpel.

T.S. Eliot got used to having his writing edited, and I'm sure you will too. Nbauman (talk) 17:23, 22 January 2008 (UTC)

Abnormal rhythms

Toozdaygirl, instead of saying,

"It is the most painless, inexpensive and quick way to measure and diagnose abnormal rhythms of the heart."

isn't it simpler to say,

"It is the best way to measure and diagnose abnormal rhythms of the heart."

I think that's what the source, Braunwald, says.

Is there a better way to measure and diagnose abnormal rhythms? Is there a better way that is painful? Nbauman (talk) 15:58, 18 February 2008 (UTC)

Color code of limb leads

Image from the article

It appears that the color coding of the electrodes for the limb leads is different in different countries. And this seems to be just the just the right place to find out more about it. I guess a small table is the easiest way to do so. Feel free to add or not to add a respective link as you see fit. --Dietzel65 (talk) 09:34, 7 May 2008 (UTC)

RA=white LA=Black LL=red RL=green

as described in the article.

Note: This appears to be the American Health Association (AHA) recommendation [10]

Used in which countries?

• USA (white on right, smoke over fire, clouds over grass). [11] Welch Allyn PIC50 defibrillator manual. Page 57, manual section 4.7. 19mb file, so use a fast connection.

JPINFV (talk) 20:59, 12 May 2008 (UTC)

• ?

RA=red LA=yellow LL=green RL=black

Called "traffic light code", at least in Germany.

Note: This appears to be the International Electrotechnical Commission (IEC) recommendation [12]

Used in:

• Germany [13] --Dietzel65 (talk) 09:34, 7 May 2008 (UTC)
• Belgium --Steven Fruitsmaak (Reply) 12:08, 9 May 2008 (UTC)
• Hungary + France Lennert B (talk) 20:48, 10 May 2008 (UTC)
• Austria --PatDin (talk) 19:32, 21 May 2008 (UTC)
• United Kingdom -- NRPanikker 17:07, 8 July 2008 (UTC)

RA=? LA=? LL=? RL=?

Are there additional color codes used anywhere? If so, please add them.

Salt --> Electrolytes

I have replaced the word salt by electrolytes, because it was just plain wrong. A salt is a compound composed of two differently charged ions (e.g. Sodiumchloride or Potassiumbicarbonate), whereas an electrolyte is an electrically active dissolved ion. I read (and generally agree with) the reasoning above about using as simple as possible words in the introduction as to not discourage readers, but I believe this should not happen at the expense of correctness. Lennert B (talk) 12:06, 11 May 2008 (UTC)

I agree that the article should be correct, but it must also be understandable to the general reader. How would you propose that we do both? The general reader won't know the term "electrolytes." My Merck Manual Home Edition (1st edition, not the online edition) says that electrolytes are dissolved salts (in my summary). Is that right? Can we say "dissolved salts (electrolytes)"? Nbauman (talk)

It's better, but still not great. However, I believe the introduction of the article Electrolytes explains it pretty good. Why not just link there? That way those unfamiliar with the term can just look it up, but the use of incorrect terminology is avoided. Lennert B (talk) 15:45, 12 May 2008 (UTC)

I don't think a layman could understand the article Electrolytes. What's a free ion? (If you click on the link for ion, you get another difficult page. What's a valence?)

"Dissolved salts" is correct terminology, BTW. The Merck Manual, which has been extensively reviewed, uses it. It's just not the technical term. Nbauman (talk) 17:51, 12 May 2008 (UTC)

It's odd that a "layman" is expected to know what a "lede" is, but not a "lead," and not to understand words like "ion" or "valence." We are all infotainment professionals, it appears, but otherwise wholly ignorant. Is it really feasible to make sense of the ECG without having a little secondary school physics and chemistry first? Therein lies the problem of infotainment: to gain the pleasure of understanding something without the pain of studying it. NRPanikker (talk) 15:28, 13 June 2008 (UTC)

Many of the people who read WP are secondary school students who are first learning physics and chemistry, and I would commend them for learning about the practical applications of those subjects as they go along. You don't fault them for that, do you?

As to your question of whether it is feasible to make sense of the ECG without already having that background, the answer is clearly yes. Look at the Merck Manual home edition (which I linked to above) which does exactly that. Nbauman (talk) 17:46, 13 June 2008 (UTC)

As a common reader of EKGs for nearly thirty years, I find an encyclopedic compendium of this fascinating subject to be most meaningful because so many with a similar interest have contributed. Indeed I would estimate 90% is well written but a bit jumbled in a noble attempt to literally explain an exceedingly complex physiologic phenomena once recorded only on paper. There is a team at work here but they are running in different vectors. Recommend a common and agreeable fact check criteria be applied to the present and future article.--Lbeben (talk) 01:51, 18 September 2008 (UTC)

Wasn't Clément Ader the inventor of the string galvanometer instead of Einthoven.

According to Jaakko Malmivuo & Robert Plonsey: Bioelectromagnetism - Principles and Applications of Bioelectric and Biomagnetic Fields, Oxford University Press, New York, 1995. chapeter 15.1 Clément Ader was the inventor of the string galvanometer. They cite Ader C (1897): Sur un nouvel appareil enregistreur pour cables sousmarins. Compt. rend. Acad. Sci. (Paris) 124: 1440-2 as source for this statement. Which is older than all papers by Einthoven on this subject.

see: [14] —Preceding unsigned comment added by Frodo Muijzer (talk • contribs) 10:28, 20 October 2008 (UTC)

• According to this PubMed article [15], a less sensitive string galvanometer was indeed invented by Ader in 1897, however, Einthoven is said to have separately invented his version of the device, suitable for the heart. These claims are also supported by this MIT of the week article. I've adjusted the WP article text with this info.

--User:OnixWP

Readership of EKG Article

Reading of the above is acknowledged. This is a wonderful, important and (my opinion) confusing article to much of the Wiki readership. I have enjoyed reading EKGs for many years but cannot for the life of me explain the concept to my (somewhat disinterested) adult sons. I am not certain about rules, but could the Electrocardiogram article be edited to an A level of understanding as well as a concurrent B level of understanding in effort to smooth ruffled feathers? Einthoven opened a keyhole on transthoracic appreciation of organized electrical activity of the heart. Evolution of this concept is rapidly advancing under the discipline of Invasive Electrophysiology. The readership of the article is probably heavily weighted to the B level of understanding. Perhaps we could better define the readership demographics and edit the article into two channels.--lbeben 03:58, 20 December 2008 (UTC)

I rewrote some of the article to make it comply with WP:MTA [16] but people keep replacing the simple language in the lead with technical jargon. I don't feel like fighting them over it. If there is consensus for simplifying it, I can easily replace the simplified text. Nbauman (talk) 19:14, 20 December 2008 (UTC)

I am a 3rd year med student and I've have never before been so confused by an explanation of ECGs. I plan to do an overhaul of this entire article as I have time. There is too much extraneous information throughout the article, and the language regarding leads is confusing (lapsing into incorrect). I suggest condensing historical information into one section so as to keep the other sections free of clutter.Walking Softly (talk) 10:13, 11 May 2009 (UTC)

Edit of Limb Leads section

I did a major edit of a small section just now. I removed a lot of historical info that I didn't think belonged in a section that a lot of people were probably going to view as (a) confusing enough already and (b) the practical "how to" section of the article. See above discussion of readability if you have thoughts of adding technical jargon back into this section. Btw, ELECTRODES go on the body. LEADS are the signals. Walking Softly (talk) 10:13, 11 May 2009 (UTC)

Image of 12-lead ECG

The diagram is horrendous. The precordial leads aren't even properly placed. I am going to change the caption to make it misleading no longer, but the whole picture needs to go. Can we please have someone do a new diagram? If someone is artistic, please let me know, and I will point you to a proper diagram to "adapt."Walking Softly (talk) 10:13, 11 May 2009 (UTC)

I have just entered the Biomedical Engineering Technician field and was drawn to this article so that I could have some clarification on ECGs. After reading the article several times, I feel that the limb leads (and below) sections are very 12-leads centric, even though most ECG monitoring doesn't use 12-lead configurations.

Thanx, Ed

The.loquitur (talk) 03:30, 9 June 2009 (UTC)

vectorcardiograms

ECG should also have info about vector cardiograms