"Sound-based" Compared to "Ultrasound-based" Diagnosis of Valvular Pathologies by Final Year Medical Students

Background: Cardiac auscultation (CA) is the cornerstone for diagnosing valvulopathies by physical examination; however, its diagnostic accuracy is suboptimal. Pocket-size ultrasound devices are used to perform focused ultrasound studies (FUS). We aim to compare "sound-based" to "ultrasound-based" diagnosis of valvular malfunction by medical students.

Methods: A cohort prospective study was conducted among 56 subjects. The subjects were examined by 3 final year medical students who received 12 hour training on cardiac ultrasound in order to diagnose common valve disorders. Each subject underwent 2 consecutive exams by the 3 students: CA and a FUS using a pocket-size ultrasound device.

Results: The study included 56 subjects. 18 of them without any valve pathology. Eighteen subjects had 2 or more valvular pathologies. Based on FUS, students improved their sensitivity and specificity by 33% and 21%, respectively for detecting mitral insufficiency compared to CA. Students` sensitivity for diagnosing mitral stenosis rose considerably from 8% based on CA to 92% by using FUS without significant drop in specificity (95% and 86% for CA and FUS, respectively). The sensitivity for diagnosing aortic valve insufficiency by CA was very low (6%) and improved by FUS (31%). Aortic stenosis was the valvular malfunction that students best identified by CA (sensitivity 67%, specificity 89%). Nonetheless, students improved their diagnosis when relied on FUS (sensitivity70%, specificity 87%). In none of the patients with at least 2 valvular dysfunctions, could students identify the pathologies when relying on CA whereas 22 cases (39%) were detected by FUS.

Conclusions: The diagnostic ability of final year medical students to detect valvular dysfunction based on CA is poor. A short training on cardiac ultrasound allows medical students to considerably improve their ability to diagnose valvular pathologies. Compared to CA, FUS is significantly better in identifying a combination of valve malfunctions in the same patient.