How reliable is a single EP study?

Posted By  CCF CARDIO MD-APS on January 19, 1998 at 12:00:35:

In Reply to: How reliable is a single EP study? posted by Peter on January 02, 1998 at 13:34:06:

: I have a simple question - Last June I had an EP study done at the London
  Health Sciences Centre in Ontario, Canada.  When the study was done I had
  recently gone off 450 mg propafenone and .25 mg digoxin for atrial fibrillation.
  In the drug-free state (1 week) prior to the study I had no arrhythmias at all.
  The study showed no evidence of a mechanism responsible.  Is is possible for
  accessory pathways to become dormant such that they wouldn't show up during the
  study?  Is a single EP study difinative?  I was considering a follow up study
  because the arrythmia is back and I have chosen to stay off the meds.  When
  I say it is back it is not afib but rather PSVT.  Actually I have only ever
  had 1 episode of afib which lasted 12 hours and needed meds to convert.  At
  this point the only time I get the disruption to the normal rhythum is when I
  swallow.  As long as I don't swallow the sinus rhythum is good.  Thanks for your
  help.

[CCF CARDIO MD APS]

Dear Peter,
   As your heart rhythm disturbance is dynamic in nature, no one particular EP study is definitive, i.e. not finding abnormal rhythms on one EP study does not mean it doesn't exist or that you are disease free.  All tests in medicine must
be taken in the context of time, the patients symptoms and signs over the preceeding months or even years.  Most patients who have a negative EP study but then develop symptoms again with or without a documented rhythm disturbance are
considered for another study.  You should discuss this option with your physician.
   Information provided in the heart forum is intended for general informational purposes only, actual diagnosis and treatment can only be made by your physician(s).