Clinical features

• hypertension or hypotension ^c  
• absent or reduced pulses ^c  
• aortic regurgitation ^c  

Why?

Hypertension on initial examination makes a distal aortic dissection slightly more likely but a proximal one less

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%)	distal aortic dissection (angiography, surgery or autopsy)	hypertension on initial examination (150/90 or more)	2.5 (1.5 to 3.6)	1.4%	0.47 (0.33 to 0.66)	0.47%
	proximal aortic dissection (angiography, surgery or autopsy)	hypertension on initial examination (150/90 or more)	0.19 (0.089 to 0.42)	0.19%	2.0 (1.6 to 2.5)	2.0%

Aortic regurgitation, hypotension and pulse deficits make a proximal aortic dissection more 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%)	proximal aortic dissection (angiography, surgery or autopsy)	aortic regurgitation	5.7 (3.3 to 9.6)	5.7%	0.39 (0.27 to 0.56)	0.39%
		hypotension on initial examination (systolic < 100)	5.3 (2.0 to 14)	5.3%	0.82 (0.71 to 0.94)	0.82%
		pulse deficits	3.9 (2.3 to 6.6)	3.9%	0.57 (0.43 to 0.74)	0.57%