Table 3. Cardiac Strain.
| Variable | Adolescents | Adults | All | ||||
|---|---|---|---|---|---|---|---|
| Mean (SD) | P valuea | Mean (SD) | P valuea | P valueb | |||
| Term (n = 20) | Preterm (n = 20) | Term (n = 32) | Preterm (n = 38) | ||||
| LV | |||||||
| Longitudinal | |||||||
| Strain, % | –14.3 (2.2) | –14.9 (2.1) | .44 | –12.7 (2.8) | –14.2 (2.4) | .04 | .02 |
| Systolic SR, % per s | –78.8 (17.0) | –83.7 (8.6) | .50 | –52.1 (13.0) | –57.5 (16.0) | .16 | .07 |
| Diastolic SR, % per s | 63.8 (15.0) | 72.9 (14.0) | .08 | 32.2 (9.2) | 37.2 (10.0) | .06 | .01 |
| Circumferential | |||||||
| Global strain, % | –19.7 (2.5) | –21.1 (2.6) | .17 | –17.8 (2.3) | –18.3 (3.4) | .30 | .08 |
| Base strain, % | –17.2 (3.1) | –17.9 (2.2) | .68 | –17.0 (2.2) | –17.2 (2.8) | .45 | .43 |
| Mid strain, % | –19.3 (2.2) | –20.5 (2.2) | .13 | –17.9 (2.1) | –18.0 (3.1) | .57 | .25 |
| Apex strain, % | –22.5 (4.0) | –25.0 (4.3) | .06 | –18.4 (4.0) | –19.9 (5.5) | .30 | .03 |
| Systolic SR, % per s | –117.0 (20.0) | –129.0 (26.0) | .29 | –82.3 (15.0) | –85.1 (19.0) | .32 | .07 |
| Diastolic SR, % per s | 122.0 (28.0) | 134.0 (38.0) | .57 | 77.7 (18.0) | 77.5 (23.0) | .95 | .27 |
| Radial | |||||||
| Global strain, % | 29.5 (6.4) | 30.8 (8.8) | .76 | 25.8 (6.8) | 27.4 (9.5) | .71 | .33 |
| Base strain, % | 30.4 (8.9) | 33.1 (10.0) | .24 | 26.4 (9.5) | 29.0 (13.0) | .50 | .18 |
| Mid strain, % | 34.4 (8.4) | 34.1 (9.7) | .68 | 29.7 (8.1) | 31.5 (10.0) | .45 | .52 |
| Apex strain, % | 23.6 (8.1) | 25.4 (11.0) | .88 | 21.4 (9.5) | 21.6 (12.0) | .78 | .74 |
| Long-axis strain, % | 24.8 (5.0) | 25.6 (5.5) | .50 | 18.4 (8.9) | 19.8 (7.5) | .52 | .35 |
| Systolic SR, % per s | 147.0 (32.0) | 157.0 (46.0) | .94 | 107.0 (32.0) | 112.0 (42.0) | .89 | .34 |
| Diastolic SR, % per s | –203.0 (55.0) | –225.0 (80.0) | .71 | –121.0 (47.0) | –131.0 (58.0) | .69 | .16 |
| RV | |||||||
| Longitudinal | |||||||
| Strain, % | –12.6 (2.6) | –12.3 (3.1) | .91 | –11.7 (3.1) | –13.5 (3.6) | .02 | .13 |
| Systolic SR, % per s | –69.5 (16.0) | –63.7 (15.0) | .29 | –51.3 (15.0) | –60.4 (15.0) | .01 | .22 |
| Diastolic SR, % per s | 53.2 (20.0) | 47.7 (19.0) | .47 | 36.0 (15.0) | 44.0 (15.0) | .04 | .31 |
| Circumferential | |||||||
| Strain, % | –9.7 (2.2) | –10.1 (2.5) | .68 | –8.3 (2.1) | –10.8 (2.4) | .001 | .001 |
| Systolic SR, % per s | –52.4 (14.0) | –59.2 (16.0) | .22 | –38.0 (11.0) | –48.9 (14.0) | .002 | .001 |
| Diastolic SR, % per s | 45.1 (13.0) | 45.7 (15.0) | .64 | 39.6 (14.0) | 42.4 (14.0) | .36 | .45 |
Abbreviations: LV, left ventricle; RV, right ventricle; SR, strain rate.
a
P values are by unpaired Wilcoxon rank sum tests within each age cohort.
b
P values are for individuals in the term and preterm groups across age cohorts by least-squares means from an age-adjusted linear model.