Publishing their findings in the March 27, 2006, edition of The Archives of Internal Medicine researchers have stressed the importance on the skilled usage of the stethoscope. The third heart sound, S3, is a low-pitched vibration that occurs in early diastole. It is present in children and adolescents, and reduces in adulthood. According to Dr.Andrew Michaels, MD, assistant professor of cardiology at UCSF and co-director of the Cardiac Catheterization Laboratory at UCSF Medical Center, the presence of S3 in adults can signify adverse cardiovascular conditions. The pathologic S3 indicates decreased compliance of the ventricles of the heart and may be the earliest sign of heart failure.
The studies were conducted on four groups of physicians, each representing a different level of training and experience board-certified cardiology attending physicians, cardiology fellows, internal medicine residents and internal medicine interns. Phonocardiography, a computerized heart sound analysis, was used as a comparison. About ninety patients between the ages of 24-91 preparing to undergo non-emergency left-sided heart catheterization for a clinical evaluation were enrolled in the study. The phonocardiography detected a third heart sound in 23 percent of these patients. The researchers found agreement between physician and phonocardiography results improved with a greater level of physician experience, with attendings and fellows having the highest amount of agreement. Interns had no significant agreement with the phonocardiography results. Phonocardiography performed better than any physician group in identifying the third heart sound.
These findings help in showing the capacity for physicians to effectively auscultate a clinically important S3. Lead author Dr. Gregory Marcus, MD, cardiology fellow at UCSF felt that they could be generalized to the practicing physician and physician-in-training. The full realization of this capacity requires both continuing interest on the part of the learner and mentorship and teaching by those with expertise.
The researchers feel that poor performance by physicians in hearing the third heart sound may be a cause for a lack of clinician confidence in the value of using auscultation as a diagnostic tool. It also shows that there is not enough training for the current medical students and physicians are increasingly relying on more sophisticated technology, such as echocardiograms and BNP levels to provide information about heart function.
Dr. Marcus concluded that its important to identify S3 sound is important in the diagnosis of heart disease, requires relatively little time and is accessible to any physician with a stethoscope. It also becomes very important he concluded as many doctors and patients do not have immediate access to the latest technology and advancement for detecting problems with the heart.