Smartphone interfaced handheld echocardiography for focused assessment of ventricular function and structure in children: A pilot study

INTRODUCTION: Miniaturized echocardiographic machines improve availability and portability and can be particularly useful for underserved and resource-limited settings. The goal of this study was to compare left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF) obtained by a newer handheld echo (HHE) machine to standard transthoracic echocardiogram (TTE) in children. METHODS: Pediatric outpatients (Birth-18 years) undergoing TTE were prospectively enrolled. HHE protocol included 2D and M-mode images from the parasternal long, short, and apical-4 chamber views. HHE and TTE measurements were reviewed for agreement. Kappa statistic was used to analyze qualitative indices while FS and LVEF were analyzed with Lin's concordance correlation coefficient (CCC) and Bland-Altman limits of agreement (loa). RESULTS: Sixty children were enrolled; 55 were included in the quantitative analysis. Mean age was 7.5 ± 5.5 years; 67% males; median HHE image acquisition duration was 2.3(1-5) minutes. Fractional shortening and EF by HHE showed good agreement with TTE [CCC = 0.82, 95%CI (0.73,0.90), mean bias -3.18%, loa (-7.00,6.44%) vs CCC = 0.81 (0.72,0.90), mean bias -0.87%, loa (-6.94,5.17%], respectively. In children ≤5 years, HHE FS (n = 20) and EF (n = 21) agreed with TTE measurement [0.59 (0.31, 0.88), mean bias 0.30%, loa (-8.5, 9.1%); 0.79 (0.63, 0.96), mean bias 0.10%, loa (-5.99, 6.14)]. Kappa values for RV size, function, and LV function were 1.00 (P < .05); 0.75 for LV size (P < .05) and 0.66 for pericardial effusion (P < .05). CONCLUSION: Handheld echo demonstrates good correlation with standard TTE for focused assessment of ventricular chamber sizes and function in children.