Wednesday, September 28, 2016

Approach to a common presentation - Syncope

In morning report we’ve had several cases that presented with syncope. Here is an approach to syncope:

1.       Get a detailed history. History is key for syncope and to help with the differential diagnosis. Ask if it is witnessed, exactly what happened before (ie. Precipitating factors such as stressors, exertion, positional changes), during (i.e. was the patient sitting/standing/changing position at the time, was there a loss of consciousness, was there a prodrome, was there facial or other injury, etc) and after (i.e. post-ictal confusion points to seizure, etc) including associated symptoms and if this has ever happened before.

Ask questions that pertain to the differential diagnosis
Cause of syncope
Features
Reflex syncope “vaso-vagal”
Increase in vagal tone
Can be associated with cough, deglutition, defecation, micturition and situational stress
Orthostatic hypotension
Associated with “pre-syncope” prodrome
Could be associated with positional changes
Associated with hypovolemia, diuretic use, vasodilator use, deconditioning, and autonomic neuropathy (such as related to Parkinson’s, diabetes and alcohol).
Cardiovascular – Arrhythmia
Either bradycardic or tachycardic arrhythmia
Often not associated with a prodrome
May have rapid loss of consciousness resulting in facial trauma
Cardiovascular – Structural
Could be related to:
Valves (aortic stenosis, mitral stenosis, etc)
Outflow obstruction: hypertrophic cardiomyopathy
Vascular: Pulmonary embolism
Pericardial: tamponade
Non-syncope causes of transient loss of consciousness
Examples:
Seizure
TIA, vertebrobasilar insufficiency
Migraine
Narcolepsy
Hypoglycemia
Psychogenic

2.       Do a complete physical exam:
a.       Including orthostatic vitals (remember orthostatic vitals are positive if there are symptoms with standing, or there is a change of ↑30/↓20/↓10 in HR/SBP/DBP – you only need to meet one of the criteria for there to be significant changes on orthostatic vitals)
3.       Risk stratify your patient: One tool is the San Francisco Syncope Rule that defines high-risk criteria for patients with syncope which includes:
a.       History of CHF
b.      Hematocrit <30 30="" o:p="">
c.       Abnormal ECG
d.      Shortness of Breath symptoms
e.      Systolic BP <90 at="" mmhg="" o:p="" triage="">
4.       Use guidelines to guide your work up:
a.       Such as the 2006 AHA/ACFF Scientific Statement on the Evaluation of Syncope (Figure 1):



References:
1.       AHA/ACCF Scientific Statement on the evaluation of syncope. Circulation. 2006;113(2):316-27.

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