Abstract 2866: Using Digital Stethoscope Data to Diagnose Stenosis in the Left Anterior Descending Coronary Artery
Background: We discovered that application of a digital filter, frequency analysis and max-min bar plotting method to data recorded using a Littmann Model 4000 stethoscope can predict stenosis in the left anterior descending coronary artery.
Methods: We studied 51 patients (28 women and 23 men) ranging from 29 to 84 years of age (mean 57) who underwent coronary angiography at the University of Minnesota Medical Center, a tertiary referral center. All patients presented with anginal chest pain and positive stress test for elective coronary angiography. A recordable stethoscope was used to record acoustic information from the 4th left intercostal space before the angiogram. If angioplasty was performed on the LAD, recordings were taken after the intervention. The two sets of recordings were analyzed using a new sound analysis method, and the resulting diagnosis was compared to the angiogram results.
Results: On the basis of coronary angiography, 17 patients had normal coronary arteries, and 18 had 50–99% LAD stenosis. The other patients had lesions either in other coronary arteries or 25–50% blockage in the LAD. This new analysis technique correctly identified normal coronary arteries in 100% of the normal cases and stenosed LAD coronary arteries in 12/18 of the patients with LAD disease. In 100% of the 12 patients, the curve associated with LAD blockage disappeared post intervention. Additionally, we have developed an automated technique that correctly classified 76% of normal and stenosed LAD patients.
Conclusions: Digital stethoscope data, taken at the 4lics, along with a computer to do the math required and proper interpretation methods of those results can be used as a tool for primary care providers to refer patients for further evaluation and risk factor modification.