Table 6.
Overview of fiducial points with shortest time difference and highest correlation to physiologic events found in the ultrasound images
| Physiologic event | Fiducial point | R | Diff (± SD) [ms] | Fiducial mean location (± SD) [ms] | Ultrasound image mean location (± SD) [ms] | Beta coefficient linear regression |
|---|---|---|---|---|---|---|
| Atrial systolic onset | Bs | 0.75** | − 2 (± 16) † | − 111 (± 24) | − 113 (± 22) | 0.70 |
| Peak atrial inflow | Cs | 0.63** | 13 (± 19) | − 73 (± 23) | − 61 (± 22) | 0.60 |
| Mitral valve closure | Es | 0.71* | 4 (± 11)† | 16 (± 14) | 19 (± 15) | 0.69 |
| Aortic valve opening | Gs | 0.60** | − 3 (± 11)† | 59 (± 11) | 55 (± 13) | 0.68 |
| Peak systolic inflow | Ks | 0.42* | 13 (± 23) | 116 (± 20) | 128 (± 22) | 0.48 |
| Aortic valve closure | Bd | 0.94** | − 5 (± 12) † | 348 (± 37) | 342 (± 30) | 0.86 |
| Mitral valve opening | Fd | 0.87** | − 7 (± 19) † | 437 (± 37) | 424 (± 38) | 0.96 |
| Peak early ventricular filling | Hd | 0.79** | − 18 (± 28) | 505 (± 41) | 485 (± 43) | 0.84 |
R = Pearsons Correlation. * = p < 0.01; ** = p < 0.001. Diff: Mean difference between fiducial point in the seismocardiogram and physiologic event found in the ultrasound image (†indicates no significant difference in time)