This episode of CRACKCast covers Rosen’s Chapter 15, Syncope. This short but high yield chapter covers Syncope, a common reason for emergency visits that may be benign, but sometimes can have more sinister diagnoses lurking that cannot be missed!
Rosen’s in Perspective:
Syncope is defined as a sudden, transient, loss of consciousness with loss of postural tone accompanied by a rapid return to baseline.
- prevalence: 1 in 5 in life-time
- wide range of life threatening to totally benign causes
- patients with known CAD who have a syncope from any cause have highest mortality
- risk factors: known cerebral vascular disease/HTN/cardiac medications
- increase mortality associated with age, CHF, CAD
- no mortality from vasovagal, orthostatic, or medication induced syncope unless patient suffers trauma/injury
Bilateral hemispheric dysfunction or Reticular Activating System (RAS) dysfunction
- majority from acute hypo-perfusion
- can be local (cerebral vasoconstriction (SAH) or systemic hypovolemia (diarrhea))
Pre-syncope and syncope are the same entity! On a spectrum from pre-syncope, syncope, to coma.
1) What are 12 critical causes of syncope
When cerebral perfusion pressure drops more than 35% the patient may have syncope
Critical causes of syncope:
- thoracic aortic dissection
- critical Aortic Stenosis
- pericardial tampondade
- abdominal aortic aneurysm
- subarachnoid bleed
- toxin mediated
- severe hypovolemic shock
- ruptured ectopic pregnancy
Other causes of syncope:
Box 15-1. Causes of syncope. Rosen’s 8th Edition. Chapter 15 – page 136.
2) List common medications that can cause syncope
Cardiac meds – can cause hypotension
QT prolonging medications – can lead to transient Torsade de Pointe
Insulin/oral hypoglycemic agents
Box 15-2. Rosen’s 8th edition. Chapter 15 – page 137.
3) Describe the San Francisco Syncope Rule
- History CHF
- Hematocrit <30%
- Abnormal ECG
- SOB on history
- SBP <90 at triage
4) What are red flags that require admission in syncope?
- chest pain
- unexplained SOB
- a hx of significant CHF or valvular disease
- patient with ECG evidence of ventricular dysrhythmias, ischemia, significantly prolonged QT intervals, or new BBB
Relative red flags (consider admission):
- age > 45
- pre-existing cardiovascular or congenital heart disease
- family history of sudden death (Brugada)
- serious comorbidities such as diabetes
- exertional syncope (HOCM, critical AS)
This post was edited and uploaded by Ross Prager (@ross_prager)