Holter test results

  I've been experiencing irregular heartbeats for several years now. Finally,
  I decided to talk to my doctor about it and was fitted with a Holter monitor
  for 24 hours.  I later received the results in a brief letter from the
  doctor basically saying that there were no abnormalities in rate or
  rhythm, even when I noted the "thumping" sensation.  I asked for a copy of
  the results and was told that they could send me a "summary" in place of
  the complete and more comprehensive results.  
  I opted for the summary, but have been wondering what some of it means.  
  First section is Ectopic Narrative.  Basically, it says the following:  
  WIDE BEATS totaled 37 representing <1% of all beats. WIDE COUPLETS totaled
  2.  PAUSES totaled 5.  ISOLATED EARLY NARROW BEATS (IENB) totaled 74 representing
  <1% of all beats.  (What do the numbers mean? <1% mean?  WIDE BEATS/COUPLETS?
  IENB? PAUSES?)
  Second section is Ischemic Narrative.  There are four lines: CH1-ST, CH2-ST
  CH3-ST:
  CH1-ST shows levels averaged +0.1mm with the MAX of +0.9mm and the MIN of -0.2mm.
  CH2-ST shows levels averaged +0.1mm with the MAX of +0.4mm and the MIN of -0.6mm.
  CH3-ST shows levels averaged -0.1mm with the MAX of +1.2mm and the MIN of -0.7mm.
  CH3-ST also says: Total minutes in excess of 1mm from the AVG was 1
  representing <1% of the time monitored.  The LONGEST duration in excess
  of 1mm from AVG was 1 minute with the onset at 15:21.
  Reading your fine forum has given me the opportunity to find out how
  many others are experiencing symtoms (symptoms) similar to mine.  I've also started
  to realize that sometimes, and probably even most of the time, this is
  just something we have to live with.  It doesn't mean we're sick or dying.
  Nevertheless, when I went to the doctor, I did it not so much to find
  out what was "wrong with me," but more with the idea of trying to
  understand the "mechanics" of what I'm going through.  Over and over, I
  hear people reporting that their doctors are basically saying, oh don't
  worry about it.  It's nothing.  You'll be fine == Ok, I can handle that.
  But I've still received no satisfaction as to the "mechanics" of the what
  my heart is doing.
  Could you please help and give me a better idea of what some of these test
  notations mean?  I'd truly appreciate it.
  Thanks.

[CCF CARDIO MD APS]

Dear Karen,
Both the upper (atrium) and lower (ventricle) chambers of the heart can produce
premature beats, which are called PACs and PVCs respectively (C stands for contraction.)
These extra, premature beats of the heart are common, 'normal', and benign.  
Unfortunately some people feel them more than others and some have more per day
than others.  If you haven't learned already from reading on this web site about
PVCs and PACs, one should avoid alcohol, tea, coffee, chocolate (anything with
caffiene in it), and avoid stress as much as possible as all of these factors
are known to increase the frequency and strength of the premature contractions.
As for the mechanics of a premature contraction, I will speak of the ventricular ones as
these are the ones that make you feel a thump in your chest, or as said by some
make you feel like your heart is trying to jump out of your chest.  The prematurity of
the beat means the muscle is still primed for contraction from the previous beat
or contraction and so another so soon on top of that results in a much more forceful
contraction of the heart muscle, and this is perceived by most as a thud, or
thump in there chest.  The electrical system of the heart works in conjuction with
the muscular walls of the heart to allow continuous pumping of blood to the lungs and throughout the
body.
The other parameters that you speak of in your summary holter report (ischemia)
are simply markers of potential decreased blood flow to the heart which sometimes
shows up on the ecg as depression of the ST interval.  This is most likely routinely
performed on all holter monitors, but just to be safe, you should ask your physician
if he/she is concerned that you are at risk for heart disease (I highly doubt this
given your symptoms that you speak of here.)  
If your really want to understand the mechanics of the heart, your best option
would be a library (regular then medical later on) which has books on the anatomy,
electrical and mechanical pump functions of the heart.  One such book would be titled
the physiology of the heart.  Good Luck.
Information provided in the heart forum is intended for general medical informational
purposes only, actual diagnosis and treatment can only be made by your physician(s).