Clinical features

• chest pain ^c and if it has moved
• onset of symptoms ^c  

Why?

Symptoms lasting longer than 24 hours makes aortic dissection slightly less likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected aortic dissection undergoing angiography c   (pre-test probability: 1%)	aortic dissection (angiography, surgery or autopsy)	prior hypertension	1.4 (1.0 to 1.9)	1.4%	0.61 (0.42 to 0.89)	0.61%
		symptoms for < 24 hours	1.5 (1.2 to 2.0)	1.5%	0.42 (0.27 to 0.67)	0.42%
		pain migration	1.3 (1.0 to 1.8)	1.3%	0.64 (0.43 to 0.93)	0.64%

• None of the following is helpful in diagnosing aortic dissection or its location ^c  
  • history of excitement triggering the pain
  • position of pain