Jul 20 - Evaluation of Syncope

Good July topic for discussion.  See this blog post from last July for an in-depth review with article links - not much new research in this area since then so no new links of note.  I will link again to this article describing the cost effectiveness of a variety of tests for sycope.  Basically it costs $17 per correct diagnosis for postural BP checks, $1000 for an ECG, and ~$20,000 for a carotid ultrasound.

19 Nov - Syncope with funky neurological symptoms on recovery

Today's case was a previously healthy 71 y/o male who sustained a witnessed syncopal attach where he fell and hit is face on the ground.  He rapidly regained consciousness, but when he awakened he could not use his hands or feet and had bilateral upper and lower extremity numbness.  Distal muscle weakness was more prononced than proximal muscle weakness.  On arrival to the hospital he was bradycardic with normal blood pressure and denied light headedness.  ECG revealed sinus bradycardia, rate ~48 with an LBBB.  Due to his neurologic signs and symptoms MRI of the cervical spine was performed which revealed cord contusion with siginificant canal stenosis and osteophytes.

Spinal cord contusions are typically seen in contact sports injuries and motor vehicle crashes.  Such an injury from a low velocity fall is unusual.  An ovid search turned up no articles reporting this occurence. 

Steroid treatment is controversial but may be effective if started within a few hours of injury.  This article reviewed current recommendations - SPINE Volume 28, Number 9, pp 941–947 and is available on Ovid full text.

As far as the bradycardia goes - he is felt to need permanent pacemaker - the AHA and ACC recently revised guidelines for permanent caridiac pacing and antiarrhythmia devices and it would be useful to be familiar with these gudelines (especially class I indications) for board purposes.

Aug 19 Syncope and Pulmonary Hypertension

This case was an elderly female with previously repaired aortic stenosis (mechanical AVR 15 years prior) who presented with recurrent syncope over the past 1 - 2 years.  The syncope occured with exertion and was increasing in frequency.  She carried a diagnosis of hypoxemic "COPD" but no PFT records were available.  PaO2 was low, and there was no evidence of CO2 retention.  She was suspected of having pulmonary hypertension by ECHO but had refused R heart catheterization to confirm. 

Will not go into discussion of syncope workup here - see this post from July 7.

Effort syncope has been described as a common symptom in primary pulmonary hypertension for quite some time.  An early effiort to identify the mechanism found progressive decreases in blood pressure ultimately resulting in acute R heart failure accounted for the syncopal attacks.  Tachy or brady arrhtyhmias occured but did not seem to be responsible for the acute drop in BP.

A nice review of primary pulmonary hypertension from AAFP is here.

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.

24 Feb - Syncope, MI, and LBBB

     Todays case was a patient with a significant underlying seizure history (poorly controlled) who now presents with several episodes of loss of consciousness not associated with convulsions.  Echocardiography revealed a rare congenital malformation - cor triatriatum.  This was likely unrelated to the syncopal event.  It is condition where atrium is divided into two chambers by a septum, which can produce symptoms the functional equivalent of mitral stenosis.
     A brief case discussion focused on patients with chest pain and left bundle branch block.  Symptoms suggestive of cardiac ischemia with a new or unknown duration LBBB should be managed as ST elevation MIs.  In patients with old LBBB and chest pain, some features suggest the presence of MI:  1mm concordant ST elevation, 5mm discordant ST elevation, or 1mm ST depression in leads V1, V2, or V3.  This data came from a substudy of the landmark GUSTO trial that established the usefulness of TPA for treatment of acute MI.  You can expect a question about MI in setting of LBBB on boards.