Figure 3.

Modified Haller index measurement, obtained by dividing the L-L thoracic diameter (A) by the A-P thoracic diameter (B). The L-L thoracic diameter is measured with the subject in the standing position and with open arms, by using a rigid ruler in centimetres coupled to a level (the measuring device), placed at the distal third of the sternum, in the point of maximum depression of the sternum. The A-P thoracic diameter is measured, during conventional transthoracic echocardiography, as the distance between the true apex of the sector (the point of entry of ultrasound into the chest) and the posterior wall of the descending thoracic aorta, visualized behind the left atrium. A-P, anteroposterior; Asc ao, ascending aorta; Desc Ao, descending aorta; LA, left atrium; L-L, latero-lateral; LV, left ventricle; RV, right ventricle. Examples of LV-GLS bull’s eye plot patterns obtained in two healthy subjects, with PE (C) and with normal chest shape (D), respectively. The PE subject (MHI >2.5) was found with a significant impairment in basal myocardial strain (light pink and pale pink segments), moderate impairment in mid myocardial strain (light red segments) and with a normal apical strain (bright red segments); the resultant LV-GLS (−17.4%) was moderately impaired. On the other hand, the subject with normal chest wall conformation (MHI ≤ 2.5) was found to have a uniformly red pattern of the bull’s eye plot, indicating normal regional and global longitudinal deformation of myocardial segments (LV-GLS = −27.2%). GLS, global longitudinal strain; LV, left ventricular; MHI, modified Haller index; PE, pectus excavatum.