https://doi.org/10.1007/s00392-024-02526-y
1Herz- und Diabeteszentrum NRW Allgemeine und Interventionelle Kardiologie/Angiologie Bad Oeynhausen, Deutschland
Background
Right ventricular (RV) failure in patients with chronic volume overload due to tricuspid regurgitation is poorly understood. Full cycle cardiac computed tomography (CT) captures the RV geometry and function throughout the cardiac cycle. Artificial intelligence (AI)-driven analysis serves as a time effective tool to analyze a broad spectrum of patients with RV dilation. The aim of the study was to assess the RV geometry across a broad spectrum of RV dilation.
Methods and results
This study includes 147 patients (mean age 77±7; 41% male, mean RV ejection fraction 48%±12%). After employment of artificial intelligence driven RV reconstruction, the cohort was divided into 5 subgroups based on the magnitude of the RV enlargement. The RV was divided into 3 segments (P1-3) and for each segment the diameter was measured in 4-chamber, 2-chamber and right ventricular outflow tract (RVOT) view, along with the area of the segment at the end of the diastole.
Compared to patients with normal RV end diastolic volume (RVEDV), we found that the RV diameter in all 3 views was significantly larger in patients with severe RV dilation (P<0.01). Enlargement of RV diameter was most pronounced in the apical part of the ventricle, additionally the ratio between apical RV diameter to mean RV diameter in 4 chamber view increased with progression of the RV dilation (P< 0.001). Furthermore, apical RV area was consistently enlarged with RV dilation (P<0.001) and ratio between 4-chamber to 2-chamber view increased significantly with progression of RV dilation (P<0.001). There was no difference in RV ejection fraction between the subgroups (P=0.276).
Conclusions
In patients with chronic volume overload, the RV shows the greatest increase of dilation in the apex. With progression of RV dilation, the geometry of the RV changed from a predominantly triangular, conic shape to a spherical, cylindric-like shape.
P1 |
Group 1 (n=32) |
Group 2 (n=28) |
Group 3 (n=23) |
Group 4 (n=25) |
Group 5 (n=37) |
P-Value |
4-Chamber view |
|
|
|
|
|
|
Basal |
|
|
|
|
|
|
absolute Value |
46±9 |
52±6 |
55±5 |
56±6 |
62±6 |
<0.01 |
Relation to Group 1 |
1 |
1.13 |
1.20 |
1.28 |
1.35 |
|
Mid ventricular |
|
|
|
|
|
|
absolute Value |
34±9 |
41±9 |
41±6 |
44±6 |
52±9 |
<0.001 |
Relation to Group 1 |
1 |
1.21 |
1.21 |
1.29 |
1.53 |
|
Apical |
|
|
|
|
|
|
absolute Value |
16±8 |
24±7 |
26±5 |
28±6 |
36±11 |
<0.001 |
Relation to Group 1 |
1 |
1.43 |
1.62 |
1.75 |
2.25 |
|
2-Chamber view
|
|
|
|
|
|
|
Basal Diameter, mm |
|
|
|
|
|
|
absolute Value |
69±12 |
72±10 |
77±10 |
82±9 |
86±10 |
<0.001 |
Relation to Group 1 |
1 |
1.04 |
1.12 |
1.19 |
1.25 |
|
Mid ventricular |
|
|
|
|
|
|
absolute Value |
63±12 |
67±8 |
75±8 |
81±11 |
87±10 |
<0.001 |
Relation to Group 1 |
1 |
1.07 |
1.19 |
1.29 |
1.38 |
|
Apical |
|
|
|
|
|
|
absolute Value |
31±8 |
36±7 |
42±5 |
44±8 |
48±9 |
<0.001 |
Relation to Group 1 |
1 |
1.16 |
1.35 |
1.42 |
1.55 |
|
RVOT |
|
|
|
|
|
|
Basal |
|
|
|
|
|
|
absolute Value |
78±19 |
83±17 |
92±17 |
99±9 |
103±14 |
<0.01 |
Relation to Group 1 |
1 |
1.06 |
1.18 |
1.27 |
1.32 |
|
Mid ventricular |
|
|
|
|
|
|
absolute Value |
70±13 |
75±7 |
81±6 |
87±9 |
94±8 |
<0.001 |
Relation to Group 1 |
1 |
1.07 |
1.16 |
1.24 |
1.34 |
|
Apical |
|
|
|
|
|
|
absolute Value |
27±12 |
38±7 |
44±6 |
47±10 |
50±8 |
<0.001 |
Relation to Group 1 |
1 |
1.41 |
1.63 |
1.74 |
1.85 |
|
|
|
|
|
|
|
|
Area |
|
|
|
|
|
|
Basal |
|
|
|
|
|
|
absolute Value |
3246±731 |
3810±563 |
4359±646 |
4702±673 |
5416±751 |
<0.001 |
Relation to Group 1 |
1 |
1.17 |
1.34 |
1.45 |
1.67 |
|
Mid ventricular |
|
|
|
|
|
|
absolute Value |
2321±593 |
2843±522 |
3270±377 |
3642±645 |
4449±767 |
|
Relation to Group 1 |
1 |
1.23 |
1.41 |
1.57 |
1.92 |
<0.001 |
Apical |
|
|
|
|
|
|
absolute Value |
534±307 |
828±285 |
1055±220 |
1164±323 |
1551±488 |
<0.001 |
Relation to Group 1 |
1 |
1.55 |
1.98 |
2.18 |
2.91 |
|
RV EF |
|
|
|
|
|
|
Group |
43.8±16.3 |
50.1±10.2 |
49±13.1 |
51.2±9.5 |
47.9±9.7 |
0.27 |
Relation to Group 1 |
1 |
1.14 |
1.14 |
1.18 |
1.09 |
|
Figure 1.AI-Reconstruction of the RV with diameters in 4-, 2-Chamber and RVOT view