Table 1. Pressure Patterns at Baseline and Response To Meal.
| Chronic Constipation (n = 15) | Controls (n = 14) | ||||
|---|---|---|---|---|---|
| Baseline | Meal | Baseline | Meal | ||
| Simultaneous Pressure Waves (SPWs) | Occurrence (/30 min) | 10.3 ± 7.7 (15) | 13.9 ± 10.3 15) | 14.7 ± 11.1 (14) | 18.7 ± 17.2 (14) |
| Maximum frequency (/min) | 1.3 ± 0.4 (11) | 1.7 ± 0.7 (11) | 1.4 ± 0.6 (11) | 1.9 ± 0.7 (11)* | |
| Average Pressure duration (s) | 15.2 ± 5.4 (14) | 14.4 ± 5.4 (13) | 15.5 ± 3.5 (13) | 13.7 ± 2.7 (13) | |
| Propagation distance (cm) | 33.8 ± 3.0 (14) | 29.6 ± 6.4 (13)** | 32.3 ± 6.5 (13) | 29.8 ± 7.1 (13) | |
| Average amplitude (mmHg) | 14.2 ± 5.6 (14) | 12.5 ± 5.4 (13) | 14.6 ± 6.7 (14) | 14.6 ± 11.1 (14) | |
| Antegrade Pressure waves (APWs) | Occurrence (/30 min) | 0.4 ± 0.8 (15) | 1.5 ± 3.0 (15) | 0.9 ± 1.7 (13) | 1.6 ± 2.6 (14) |
| Maximum frequency (/min) | (0) | 1.6 ± 1.3 (2) | 2.0 (1) | 2.2 ± 1.0 (3) | |
| Average Pressure duration (s) | 15.3 ± 3.5 (4) | 17.8 ± 3.4 (6) | 16.1 ± 7.3 (4) | 14.1 ± 4.5 (7) | |
| Propagation distance (cm) | 21.3 ± 10.8 (4) | 26.4 ± 11.2 (6) | 29.3 ± 6.2 (5) | 30.2 ± 6.3 (8) | |
| Average amplitude (mmHg) | 19.6 ± 22.4 (4) | 22.0 ± 10.3 (6) | 20.5 ± 9.2 (5) | 18.6 ± 8.8 (8) | |
| Retrograde Pressure Waves (RPWs) | Occurrence (/30 min) | 0.1 ± 0.3 (15) | 0.7 ± 1.6(15) | 0.6 ± 1.9 (14) | 0.7 ± 1.4 (14) |
| Maximum frequency (/min) | (0) | (0) | 0.4 (1) | (0) | |
| Average Pressure duration (s) | 15.0 (1) | 11.7 ± 4.1 (4) | 21.9 ± 7.2 (2) | 16.0 ± 5.3 (5) | |
| Propagation distance (cm) | 18.0 (1) | 19.9 ± 8.3 (4) | 26.0 ± 14.1(2) | 24.9 ± 10.6 (5) | |
| Average amplitude (mmHg) | 12.0 (1) | 26.6 ± 9.1 (4) | 15.8 ± 14.3 (3) | 17.6 ± 7.5 (6) | |
| Isolated Pressure Transients | Maximum amplitude (mmHg) | 132.7 ± 53.8 (15) | 138.4 ± 44.9 (15) | 113.4 ± 51.7 (14) | 108.8 ± 47.1 (13) |
| Percentage of sensors involved | 36.4 ± 15.0 (15) | 39.3 ± 17.2 (15) | 37.6 ± 15.2 (14) | 39.0 ± 15.2 (14) | |
| Percentage of time involved | 70.1 ± 18.1 (15) | 68.6 ± 14.3 (15) | 69.4 ± 16.4 (13) | 62.7 ± 19.9 (13) | |
| Percentage with amplitude < 50 mmHg | 97.6 ± 8.6 (15) | 99.3 ± 1.5 (15) | 99.97 ± 0.1 (14) | 99.6 ± 1.4 (14) | |
| Percentage with amplitude 50–100 mmHg | 49.7 ± 22.5 (15) | 55.0 ± 23.8 (15) | 37.8 ± 30.3 (14) | 32.3 ± 22.6 (14)# | |
| Percentage with amplitude > 100 mmHg | 21.5 ± 16.4 (15) | 22.6 ± 15.7 (15) | 15.6 ± 13.5 (14) | 12.3 ± 12.1 (14) | |
| High amplitude pressure waves (HAPWs) | Occurrence (%) | 1 (7.1%) (15) | 2 (14.3%) (15) | 0 (0%) (14) | 2 (14.3%) (14) |
| Synchronized haustral pressure waves | Occurrence (%) | 1 (7.1%) (15) | 9 (64.2%) 15)*** | 1 (7.7%) (14) | 4 (30.8%) (14) |
Values are expressed as mean ± SD.
* P = 0.027 (t = −2.6, df = 9), **P = 0.024 (t = 2.6, df = 11), before and after meal, same subject group (paired samples t test). #P = 0.025 (B = −15.4, 95% CI −2.1 to −28.8) for post meal in constipation vs post meal in control (Multiple linear regression, adjusted for baseline values). ***P = 0.008 before and after meal, using McNemar’s test, same subject group. No statistical analysis was performed when n =< 5. Synchronized haustral pressure waves always alternated with segmental haustral activity.