They're still worth listening for, but don't be misled if you can't hear them: The absence of S₃ and S₄ isn't enough to rule out ventricular dysfunction, according to a recent study. Clinicians have traditionally relied on auscultation of S₃ and S₄ sounds to diagnose left ventricular dysfunction, but the diagnostic value of these findings has been questioned-especially given the variation in clinicians' ability to hear extra heart sounds.

Studying 90 adults undergoing elective left-sided cardiac catheterization, researchers found that detecting S₃ or S₄ wasn't a sensitive marker of left ventricular dysfunction. However, although S₃ or S₄ weren't always present in patients with heart failure, nearly all of those in whom these sounds were detected had cardiac dysfunction. So the researchers recommend that clinicians still consider auscultation the first step in patient evaluation before ordering more expensive and possibly invasive testing.

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