Three-Dimensional Modelling of Indexed Papillary Muscle Displacement in Patients Requiring Mitral Valve Surgery Using Four-Dimensional Echocardiography Variables

<b>Background</b>: Two-dimensional and three-dimensional echocardiographic imaging are commonly used in assessing ischemic mitral regurgitation (IMR) and degenerative mitral regurgitation (DMR) in patients with mitral valve disease. However, the use of 4D echocardiographic imaging has not yet been reported. The objectives of this study were to explore the efficacy of utilizing 4D echocardiographic variables, determine papillary muscle displacement in patients with either IMR or DMR, and compare the differences in papillary muscle displacement between groups. <b>Methods</b>: Thirty-four patients were divided into two groups: Group 1 (with IMR) and Group 2 (with DMR). Using clinical ultrasound software, 4D echocardiographic variables were obtained and compared between the groups. Pearson's product-moment correlation test was used to assess the relationship between the presence of IMR and both papillary muscle displacement and indexed papillary muscle displacement. <b>Results</b>: The mean values for papillary muscle displacement in Groups 1 and 2 were 38 ± 6.7 mm and 31.8 ± 6.1 mm, respectively. Indexed papillary muscle displacement was 22.8 ± 3.7 mm in Group 1 and 18.4 ± 3.5 mm in Group 2. There were statistically significant correlations between the presence of IMR and papillary muscle displacement (<i>p</i> = 0.009) and indexed papillary muscle displacement (<i>p</i> = 0.002). A significant correlation was also observed between IMR and PL (<i>p</i> = 0.001), with mean values of 15.7 ± 3.9 mm in Group 1 and 20.2 ± 5.6 mm in Group 2. <b>Conclusions</b>: Four-dimensional echocardiography is effective in evaluating morphological variations in IMR. It successfully determined papillary muscle displacement in patients undergoing mitral valve surgery and demonstrated a positive correlation between IMR and indexed papillary muscle displacement.