Relationship between accurate auscultation of a clinically useful third heart sound and level of experience.
BACKGROUND
Poor performance by physicians-in-training and interobserver variability between physicians have diminished clinicians' confidence in the value of the third heart sound (S3).


METHODS
To determine whether auscultation of a clinically useful S3 improves with advancing levels of experience, we performed a prospective, blinded, observational study of 100 patients undergoing left-sided heart catheterization. Patients underwent blinded auscultation by 4 physicians (each from 1 of 4 different levels of experience), phonocardiography, measurement of blood B-type natriuretic peptide levels, echocardiography for measurement of left ventricular ejection fraction, and cardiac catheterization for measurement of left ventricular end-diastolic pressure.


RESULTS
Whereas residents' and interns' auscultatory findings demonstrated no significant agreement with phonocardiographic findings, an S3 auscultated by cardiology fellows (kappa = 0.37; P<.001) and cardiology attendings (kappa = 0.29; P = .003) agreed with phonocardiographic findings. Although the sensitivities of the S3 were low (13%-52%) for identifying patients with abnormal measures of left ventricular function, the specificities were high (85%-95%), with the best test characteristics exhibited by phonocardiography and more experienced physicians. The S3 detected by attendings and fellows was superior in distinguishing an elevated B-type natriuretic peptide level, a depressed left ventricular ejection fraction, or an elevated left ventricular end-diastolic pressure (P = .002-.02 for attendings and .02-.03 for fellows) compared with residents (P = .02-.47) or interns (P = .09-.64).


CONCLUSIONS
The S3 auscultated by more experienced physicians demonstrated fair agreement with phonocardiographic findings. Although correlations were superior for phonocardiography, the associations between the S3 and abnormal markers of left ventricular function improved with each level of auscultator experience.
Division of Cardiology, University of California, San Francisco 94143-0124, USA.
Gregory M
GM
Marcus
Gregory
G
Marcus
Joshua
J
Vessey
Mark V
MV
Jordan
Michele
M
Huddleston
Barry
B
McKeown
Ivor L
IL
Gerber
Elyse
E
Foster
Kanu
K
Chatterjee
Charles E
CE
McCulloch
Andrew D
AD
Michaels
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization; D002309:Cardiology / Q000193:education; D002983:Clinical Competence; D003936:Diagnosis, Computer-Assisted; D003971:Diastole / Q000502:physiology; D004452:Echocardiography; D005260:Female; D006347:Heart Sounds; D006801:Humans; D007396:Internship and Residency; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010701:Phonocardiography; D010820:Physicians; D011446:Prospective Studies; D012495:San Francisco; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology
D020097:Natriuretic Peptide, Brain