## 3 Results
### Characteristics of Study Population
In the B-A direction, the systolic RMS force revealed differences between controls and trivial-mild MR (1.41 \(\pm\) 0.27 vs. 0.80 \(\pm\) 0.47, \(p\)-value = 0.001, reflecting a 43.26% decrease), controls and mild-moderate MR (1.41 \(\pm\) 0.27 vs. 0.83 \(\pm\) 0.35, \(p\)-value = 0.001, indicating a 41.1% decrease), trivial-mild and moderate-severe MR (0.80 \(\pm\) 0.47 vs. 1.37 \(\pm\) 0.24, \(p\)-value = 0.02, showing a 71.25% increase), and mild-moderate and moderate-severe MR (0.83 \(\pm\) 0.35 vs. 1.37 \(\pm\) 0.24, \(p\)-value = 0.021, signifying a 65% increase). Furthermore, the diastolic RMS force in the S-L direction revealed notable differences between controls and mild-moderate MR, moderate-severe MR (0.08 (0.06) vs. 0.14 (0.12) and 0.21 (0.63), \(p\)-value = 0.027 and 0.024, representing a 75% and 61.9% increase, respectively). Additionally, significant differences were observed between trivial-mild and moderate-severe MR (0.06 (0.12) vs. 0.21 (0.63), \(p\)-value = 0.045, indicating a 71.4% increase). Notable differences were also observed in the diastolic I-A direction, between controls, mild-moderate MR, and moderate-severe MR (0.07 (0.07) vs. 0.11 (0.09), 0.29 (0.42), \(p\)-value = 0.05 and 0.001, demonstrating a 57.1% and 75.9% increase, respectively) and between mild-moderate and moderate-severe MR (0.11 (0.09) vs. 0.29 (0.42), \(p\)-value = 0.021, showing a 62.1% increase). RMS Ratio. The systolic RMS ratio demonstrated significant differences between controls and trivial-mild, and mild-moderate MR (0.65 (0.18) vs.1.21 (1.04) and 0.85 (0.61), \(p\)-value = 0.008 and 0.002, indicating an 86.2% and 30.8% increase compared to controls, respectively). Similarly, the diastolic RMS ratio demonstrated significant increases in mild-moderate and moderate-severe MR when compared to controls (0.33 (0.19) vs. 0.64 (0.66) and 0.58 (0.44), \(p\)-value = 0.016 and 0.016, indicating a 48.4% and 43.1% increase, respectively). Visual representation of the data, as illustrated in Figure 3, further accentuates the discernible differences between controls and various MR severities for HDF. \begin{table}
\begin{tabular}{l l l l l l l} \hline \hline  & & **Controls** & **Trivial–Mild** & **Mild–Moderate** & **Moderate–Severe** & **\(p\)-Value** \\  & & **(n = 15)** & **(n = 9)** & **(n = 11)** & **(n = 6)** & **\(p\)-Value** \\ \hline HDF & Direction & & & & & \\ \hline \multirow{2}{*}{ \begin{tabular}{l} AVG \\ (mN/mL) \\ \end{tabular}  } & Sytole S-L & 0.55 (0.22) \(\bullet\blacksquare\) & 0.35 (0.8) & 0.30 (0.33) \(\bullet\) & 0.25 (0.39) \(\blacksquare\) & 0.048 \({}^{*}\) \\  & Sytole B-A & 0.49 (0.26) \(\blacktriangle\) & 0.25 (0.31) \(\blacktriangle\) & 0.24 (0.13) \(\bullet\) & 0.42 (0.67) & 0.002 \({}^{**}\) \\  & HDF B-A & 0.50 \(\pm\) 0.14 & 0.27 \(\pm\) 0.23 \(\square\) & 0.30 \(\pm\)0.26 \(\square\) & 0.63 \(\pm\) 0.26 \(\square\)\(\square\) & 0.003 \({}^{**}\) \\ \hline \multirow{2}{*}{\ \begin{tabular}{l} RMS \\ (mN/mL) \\ \end{tabular}  } & Sytole I-A & 0.34 \(\pm\) 0.12 \(\blacksquare\) & 0.42 \(\pm\) 0.21 & 0.41 \(\pm\) 0.13 & 0.59 \(\pm\) 0.22 \(\blacksquare\) & 0.025 \({}^{*}\) \\  & Sytole B-A & 1.41 \(\pm\) 0.27 \(\blacktriangle\) & 0.80 \(\pm\) 0.47 \(\square\) & 0.83 \(\pm\) 0.35 \(\circ\bullet\) & 1.37 \(\pm\) 0.24 \(\square\) & 0.000 \({}^{**}\) \\  & Diastole S-L & 0.08 (0.06) \(\blacksquare\) & 0.06 (0.12) \(\square\) & 0.14 (0.12) \(\bullet\) & 0.21 (0.63) \(\blacksquare\) & 0.028 \({}^{*}\) \\  & Diastole I-A & 0.07 (0.07) \(\blacksquare\) & 0.15 (0.27) & 0.11 (0.09) \(\bullet\) \(\circ\) & 0.29 (0.42) \(\blacksquare\) & 0.007 \({}^{**}\) \\ \hline \multirow{2}{*}{ \begin{tabular}{l} Ratio \\ \end{tabular}