7 July - Evaluation of Syncope

The first MR of the academic year focused on a 78 year old patient with a history of syncope.  He had two prior episodes over the preceeding three years.  The most recent event had a few second prodrome followed by loss of consciousness and a fall to the floor.  He had a history of DM and treated hypertension, but blood glucose and blood pressure checked by family were normal.  ECHO and ECG were normal.  Postural blood pressure measurements were normal.  The most likely diagnosis in this case was neurocardiogenic syncope.

The evaluation of syncope usually results in unnecessary testing that rarely leads to a diagnosis.  The frequent use of carotid ultrasound is unsupported by evidence and rarely if ever alters patient management.  Even routine lab testing, including cardiac enzymes, are almost always a wast of money unless there are clinical symptoms other than syncope to suggest their use.  This Archives of Internal Medicine article summarizes the diagnostic yield of most commonly used tests.  The highest yield test was also the cheapest - postural blood pressure management.  This 2000 NEJM review directed at primary care physicians walks you through the preferred, rational evaluation of this condition.

The evaluation of neurocardiogenic syncope is summarized in this 2005 NEJM article.  Tilt table testing remains the gold standard for evaluation of this condition.  Treatment has traditionally been with beta blockers, however there is little evidence to show they work.  Midodrine, fludrocortisone, and SSRIs have all been shown to be effective.

Remember - syncope is a finding, not a diagnosis, but in most cases you need little more than your brain, ears, and hands to make the diagnosis.