Fig 1.
Schematic of the ex-vivo heart apparatus [24].
Fig 2.
Eight sonocrystals (2 mm in diameter) sutured around the valve annulus (a) before the experiment and (b) after the experiment. The pulmonary side of the heart has been cut open for better visualization of the positions of the crystals.
Fig 3.
Method used to calculate the area, circumference, and radius of the annulus.
A lower resolution of the original triangulation is presented for illustrative purposes.
Fig 4.
Average right ventricular pressure (RVP), pulmonary artery pressure (PAP), and right atrial pressure (RAP) measured for the intact and post chordae rupture (PCR) cases.
Fig 5.
Comparison of the average values of (a) the area, (b) circumference, and (c) radius between the intact and post chordae rupture (PCR) conditions at minimum and maximum right ventricular pressure (RVP). The Wilcoxon signed rank test p-values for area, circumference, and radius were 0.01 at maximum RVP and 0.04 at minimum RAP. The asterisks (*) show significant differences (p < 0.05, Wilcoxon signed rank test). Error bars show the standard errors.
Table 1.
Calculated area at minimum and maximum right ventricular pressure (RVP) for intact and post chordae rupture (PCR) conditions.
The values are presented for all eight hearts used in the experiments along with the average (AVG) and standard deviation (STD). Comparing the average values showed an increase in the area post chordae rupture.
Table 2.
Calculated circumference at minimum and maximum right ventricular pressure (RVP) for intact and post chordae rupture (PCR) conditions.
The values are presented for all eight hearts used in the experiments along with the average (AVG) and standard deviation (STD). Comparing the average values showed an increase in the circumference post chordae rupture.
Table 3.
Calculated radius using the triangulation method (R) along with the radii calculated from the area (RA) and circumference (RC), using the assumption of flat annuli, at minimum and maximum right ventricular pressure (RVP) for intact and post chordae rupture (PCR) conditions.
The values are presented for all eight experimental hearts along with the average (AVG) and standard deviation (STD). Comparison between R, RA, and RC showed that the three different methods of calculating the radius produced the same results.
Fig 6.
Comparison of the dilation (due to the chordae rupture) between annulus anterior segment (AAS), annulus posterior segment (APS), and annulus septal segment (ASS) at maximum right ventricular pressure (RVP).
The Wilcoxon signed rank test p-values were 0.55, 0.38, and 0.74 between the AAS and APS, the AAS and ASS, and the APS and ASS, respectively. No significant differences were observed (p > 0.05, Wilcoxon signed rank test). Error bars show the standard errors.
Table 4.
Geometric dilation in area, circumference, and radius of the heart annuli due to chordae rupture at maximum right ventricular pressure (RVP) calculated using Eq (1) along with the average (AVG) and standard deviation (STD) for each quantity.
Table 5.
Dilation in the length of annulus anterior segment (AAS), annulus posterior segment (APS), and annulus septal segment (ASS) due to the chordae rupture at maximum right ventricular pressure (RVP) calculated using Eq (1) along with the average (AVG) and standard deviation (STD) for each quantity.
The largest dilation occurred at the AAS.
Fig 7.
Changes in (a) area, (c) circumference, and (e) radius as well as the absolute values of (b) area, (d) circumference, and (f) radius throughout the cardiac cycle averaged over all the annuli for intact and post chordae rupture (PCR) conditions. The shaded regions show the standard errors. The temporal position of the maximum right ventricular pressure (RVP) as well as the opening and closure of the tricuspid and pulmonary valves for the intact case are shown in the graphs as a better illustration of the deformations that occur throughout the cardiac cycle.
Fig 8.
Comparison of the change in the length of the annulus anterior segment (AAS), annulus posterior segment (APS), and annulus septal segment (ASS) in intact and post chordae rupture (PCR) conditions at maximum right ventricular pressure (RVP).
The PCR values include the dilation as well. For a comparison of the change in length between the intact and PCR conditions, the Wilcoxon signed rank test was used; p-values were 0.02 for AAS and ASS and 0.38 for APS. The p-values were 0.03, 0.02, and 0.84 for the comparison of the change in length for the intact case between the AAS and APS, the AAS and ASS, and the APS and ASS, respectively. The asterisks (*) indicate significant differences (p < 0.05, Wilcoxon signed rank test). Error bars show the standard errors.
Table 6.
Average geometric changes at maximum right ventricular pressure (RVP) for intact and post chordae rupture (PCR) conditions calculated using Eq (2).
The last column shows the percentage of the change in geometric parameters with intact-to-PCR dilation included in calculations. The geometrical parameters at minimum RVP were selected as the reference to calculate the changes.