UNDERSTANDING THE ECG

[aron]

I am trying to understand why the ECG does what it does. can someone email me a response to the following questions:


1. What is a positive electrode? What is the difference between it and a negative electrode?

2. Does an electrode sense the charge OUTSIDE the myocardial cells or INSIDE them. In other words...why is it that when a wave of depolarization sweeps towards an electode, a POSITIVE deflection is recorded? Does that mean that relative to the outside charge at the wave front, that the charge where the electrode is, is more positive? (did that make sense)

3. What is a lead? Why do you only have 4 frontal electrodes (2 on the ankles and 2 on the wrists) but get out of them 6 limb leads? What does it mean to "make" one electrode negative relative to another?


Id really appreciate your help!!!!! You can email me a response to: ***@****


THANK YOU

[Cleveland Clinic, MD]

Thanks for your questions.  You obviously have a mechanical interest in ECG recording.  I would recommend the book by D. Dubin "Electocardiography".  This is a easy to read book that will answer all you questions.  Good luck.

[Deb]

Hi,

I am in the medical field and an EKG tech, and I think that with all the info out there and the amount of questions you have, it might be best to get a book at the library, or the book store.  Here is a site that may help too.  There is a ton of information on the web.  If the wonderful doctors have the time to answer all your questions, GOD BLESS them !    
http://www.cardioassoc.com/patient_pgs/procedures/ekg.asp

Take care.

[Cleveland Clinic, MD]

Thanks for the site.  Dubin's book is published by cover publishing company and the full title is "rapid interpretation of EKG's".

[Linda Miles]

I just had a new EKG (1/31/2000)which was determined "abnormal". I had a stress test (with the injected drug) the next day. However, I have not received all the results/explanations yet: I would appreciate interpretation in easy terms about the EKG:
"Normal sinus rhythm, left anterior fascicular block, moderate voltage criteria for LVH, T-wave abnormality, and lastly:
consider lateral ischema."
I am diabetic, hypertensive, 52 year old woman.
I would appreciate your comments, as I don't see my doctor until 2/25 (unless more problems occur).  Thanks so much!

[margaret]

I recently went to the Doctor for some Asthma medicine and while there the doctor did a EKG and found it was abnormal.  The Doctor felt I may have had a heart attack.  He sent me to the hospital where they ran an Enzyme test which showed negative.  I have had EKGs in the past that were fine.  They also found a slight murmur that has never been present before.  They sent me home because the enzyme test was negative but I am still concerned.  I have trouble walking from my livingroom to my bedroom without becoming short of breath and my chest still has some pressure and pain.  Should I be concerned.  I am a 41 year old female with no prior history of heart problems.  I wish the doctor had sone a stress test.  would this show any problems that I may be having even if I have not had a heart attack.  I had severe chest pain starting in the center of my chest and radiating to the back as if a hollow point bullet went through me for approximately one and a half days.  This pain started with very short breaths and as the pain got worse I was rolled up in a ball with a pillow over my chest at its peak for approximately one and a half hours.  should I seek follow up treatment. and whatdoes any of this mean?  I had three EKGs that were abnormal.  any help in this matter would be apprecitated.