Estimation of pressure gradients by auscultation: an innovative and accurate physical examination technique.
BACKGROUND
Knowledge of pressure gradients across valves, arteries, and ventricular septal defects (VSD) is important in patient management. It was determined how well such gradients can be estimated by auscultation of a murmur's frequencies.


METHODS
In 151 patients with pulmonary stenosis (PS) (n = 77), aortic stenosis (AS) (n = 30), or VSD (n = 44), the auscultation gradient was estimated by a murmur's frequencies by use of an "auscultatory scale." The auscultation gradient was recorded before Doppler echocardiography was performed by a blinded cardiac sonographer.


RESULTS
Auscultation correlated highly with Doppler echocardiography (Doppler = 0.99. Auscultation + 7.12; r = 0.84, P <.0001). Agreement was good (mean difference [Auscultation - Doppler] = -6.8 +/- 15.8 mm Hg). In 95 patients (63%), agreement was within 10 mm Hg. Auscultation was more accurate when Doppler gradients were < or =60 mm Hg (r = 0.76, P <.0001, vs r = 0.22, P not significant for >60 mm Hg; mean difference -2.6 +/- 10.6 mm Hg vs -16.5 +/- 20.9 mm Hg for >60 mm Hg, P <.0001). Among lesions, PS showed the highest correlation, although agreement for PS, AS, and VSD was not significantly different. Isolated valvar PS showed excellent accuracy (r = 0.92, P <.0001; mean difference -5.6 +/- 8.9 mm Hg).


CONCLUSIONS
Auscultation of a murmur's frequency composition can estimate gradients accurately in most patients with PS (especially valvar PS), AS, or VSD, although it is less accurate for gradients >60 mm Hg. This innovative technique can improve diagnostic accuracy, thereby further substantiating the value of physical examination.
New York University School of Medicine, Pediatric Cardiology Program, NYU Medical Center, 540 First Ave., New York, NY 10016, USA. colin.phoon@med.nyu.edu
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D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003326:Coronary Circulation; D015150:Echocardiography, Doppler; D006326:Heart Auscultation; D006337:Heart Murmurs / Q000209:etiology / Q000503:physiopathology*; D006345:Heart Septal Defects, Ventricular / Q000175:diagnosis / Q000503:physiopathology; D006349:Heart Valve Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011237:Predictive Value of Tests; D011666:Pulmonary Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology