Comparison of cardiac output measured by phonocardiography and transthoracic echocardiography in patients with valvular disease and congenital heart anomalies

Abstract

Background: The aim of this study was to compare cardiac output (CO) between two methods of phonocardiography and transthoracic echocardiography in patients with valvular disease and congenital heart anomalies. Methods: Seventy one patients (39 males and 32 females) ranging from 5 days to 13 years (mean: 22.5 months) were enrolled in the study and CO was obtained using transthoracic echocardiography. Afterwards, their heart sounds were recorded using an electronic stethoscope and analyzed to calculate CO and ejection fraction (EF). These amounts were compared to each other using statistical tests. Findings: The mean CO reported by transthoracic echocardiography and phonocardiography was reported 4.62 (SD = 0.98) and 4.55 (SD = 0.96), respectively. Comparison of these values between two methods showed that CO amounts are both significantly higher from transthoracic echocardiography (P < 0.05). Pearson correlation analysis showed a statistically significant correlation between CO among two methods (Pearson coefficient: 0.99 and 0.74 respectively; P < 0.05). Conclusion: This study showed that phonocardiography cannot be an exact alternative for transthoracic echocardiography to report CO; however, considering the significant correlation between these amounts, it can give us an acceptable estimation of heart condition by CO and should be used cautiously. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved.