“…One study used three-dimensional (3D) echocardiography in addition to M-mode and 2D, another utilised 3D only and a third study used a rarely practiced echocardiographic technique called acoustic quantification [ 18 , 21 , 22 ]. Anthropometric and non-anthropometric measures were used for normalising the results: body surface area (BSA) in 18 studies, height ( n = 4) [ 8 , 11 , 17 , 28 ], weight ( n = 3) [ 10 , 20 , 35 ], age ( n = 2) [ 14 , 15 ], and lean body mass ( n = 1) [ 7 ]. The remaining studies used age and heart rate, ( n = 1); [ 22 ] age and BSA, ( n = 2); [ 26 , 37 ] age and height, ( n = 1); [ 27 ] height and BSA, ( n = 1); [ 33 ] weight and BSA, ( n = 1) [ 36 ] and one study used height, BSA and lean body mass [ 25 ].…”