Investigations

• Echocardiography (preferably transesophageal)  - looking for vegetations ^b

Why?

Patient b c	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
infective endocarditis (pre-test probability: 38%)	perivalvular abscesses (pathological evidence)	2-D transthoracic echocardiogram	5.4 (1.9 to 15)	77%	0.23 (0.11 to 0.46)	27%
		tranesophageal echocardiogram	16 (6.2 to 42)	91%	0.14 (0.065 to 0.29)	8%

• The left heart is affected more than the right (88% compared with 7% of cases) ^c
• The aortic valve is affected in 25%-36% of cases and the mitral valve in 29%- 33% ^{b c}
• Patients with vegetations are not clearly at increased risk of emboli. ^b