# The Evolving Stethoscope: Insights Derived from Studying Phonocardiography in Trainees

## TL;DR

This study examines how using phonocardiography (PCG) and PCG-capable stethoscopes affects medical students' ability to identify heart sounds.

## Contribution

The study provides new insights into how PCG impacts the identification of specific heart sounds by medical trainees.

## Key findings

- PCG improved identification of low-frequency heart sounds like mitral stenosis and S4.
- PCG reduced or had little effect on identifying higher-frequency heart sounds like ventricular septal defect and S3.
- Students with PCG-capable stethoscopes were better at identifying cardiac friction rub.

## Abstract

Phonocardiography (PCG) is used as an adjunct to teach cardiac auscultation and is now a function of PCG-capable stethoscopes (PCS). To evaluate the efficacy of PCG and PCS, the authors investigated the impact of providing PCG data and PCSs on how frequently murmurs, rubs, and gallops (MRGs) were correctly identified by third-year medical students. Following their internal medicine rotation, third-year medical students from the Georgetown University School of Medicine completed a standardized auscultation assessment. Sound files of 10 different MRGs with a corresponding clinical vignette and physical exam location were provided with and without PCG (with interchangeable question stems) as 10 paired questions (20 total questions). Some (32) students also received a PCS to use during their rotation. Discrimination/difficulty indexes, comparative chi-squared, and McNemar test p-values were calculated. The addition of phonocardiograms to audio data was associated with more frequent identification of mitral stenosis, S4, and cardiac friction rub, but less frequent identification of ventricular septal defect, S3, and tricuspid regurgitation. Students with a PCS had a higher frequency of identifying a cardiac friction rub. PCG may improve the identification of low-frequency, usually diastolic, heart sounds but appears to worsen or have little effect on the identification of higher-frequency, often systolic, heart sounds. As digital and phonocardiography-capable stethoscopes become more prevalent, insights regarding their strengths and weaknesses may be incorporated into medical school curricula, bedside rounds (to enhance teaching and diagnosis), and telemedicine/tele-auscultation efforts.