Does this patient have an abnormal systolic murmur?
E. Etchells, C. Bell and K. Robb
Division of General Internal Medicine and Clinical Epidemiology, University of Toronto, Ontario. eetchells@torhosp.toronto.on.ca
Our objective was to review the available evidence of the precision and
accuracy of the clinical examination for abnormal systolic murmurs. We
conducted a MEDLINE search, manually reviewed all reference lists, and
contacted authors of published studies. Each study was independently
reviewed by 2 observers and graded for methodologic quality. We found that
most studies were conducted using cardiologist examiners. In the clinical
setting, the reliability of detecting systolic murmurs was fair (kappa,
0.30-0.48). The most useful findings for ruling in aortic stenosis are a
slow rate of rise of the carotid pulse (positive likelihood ratio,
2.8-130), mid to late peak intensity of the murmur (positive likelihood
ratio, 8.0-101), and decreased intensity of the second heart sound
(positive likelihood ratio, 3.1-50). The most useful finding for ruling out
aortic stenosis is the absence of murmur radiation to the right carotid
artery (negative likelihood ratio, 0.05-0.10). Smaller, lower-quality
studies indicate that cardiologists can accurately rule in and rule out
mitral regurgitation, tricuspid regurgitation, hypertrophic cardiomyopathy,
and echocardiographic mitral valve prolapse. We conclude that the clinical
examination by cardiologists is accurate for detecting various causes of
abnormal systolic murmurs. Studies of the clinical examination by
noncardiologists are needed.
