Table 2.
AF characteristics according to ECG parameters among 419 AF patients
| Cumulative AF burden, % [95% CI] | Number of AF episodes (SD) | Mean episode duration, hour (SD) | Maximum episode duration, hour (SD) | Any episode ≥24 h (%) | ||
|---|---|---|---|---|---|---|
| PR interval | 120–200 ms (n = 332) | 1.5 [1.2–1.9] | 80.5 (209.3) | 6.9 (21.3) | 72.4 (321.7) | 63 (19.0) |
| <120 or >200 ms (n = 85) | 1.6 [1.0–2.4] | 118.5 (167.8) | 5.6 (18.6) | 54.4 (248.8) | 17 (20.0) | |
| P-wave duration | ≤120 ms (n = 368) | 1.4 [1.1–1.7] | 82.9 (190.1) | 5.8 (19.3) | 64.2 (309.2) | 65 (17.7) |
| >120 ms (n = 48) | 2.4 [1.4–4.4] | 130.8 (276.6) | 13.2 (29) | 105 (303.2) | 15 (31.2) | |
| P-wave voltage in Lead I | ≥100 µV (n = 34) | 2.2 [1.1–4.5] | 51.1 (95) | 9.4 (20.5) | 132.9 (465) | 9 (26.5) |
| <100 µV (n = 380) | 1.5 [1.2–1.8] | 90.9 (208.1) | 6.5 (20.8) | 63.5 (291.4) | 71 (18.7) | |
| P-wave axis | 0–75° (n = 332) | 1.5 [1.2–1.9] | 77.4 (192.3) | 7.1 (22.4) | 63.8 (287) | 63 (19.0) |
| <0° or >75° (n = 77) | 1.8 [1.1–2.8] | 142.2 (242.9) | 5.5 (12.6) | 94.6 (399.4) | 15 (19.5) | |
| P-wave terminal force in Lead V1 | ≤4000 ms × µV (n = 340) | 1.5 [1.2–1.9] | 92.7 (214.7) | 6.2 (20.4) | 58.6 (268.5) | 62 (18.2) |
| >4000 ms × µV (n = 74) | 1.7 [1.0–2.7] | 64.3 (122.2) | 8.8 (22.6) | 118.1 (450.4) | 18 (24.3) | |
| IAB | No (n = 374) | 1.4 [1.1–1.7] | 83.2 (189.2) | 5.9 (19.3) | 64 (306.9) | 66 (17.6) |
| Yes (n = 42) | 2.6 [1.4–4.8] | 135.3 (291.9) | 13.9 (30.1) | 112.1 (322.2) | 14 (33.3) | |
| QTc interval | ≤450 ms (n = 367) | 1.4 [1.1–1.7] | 75.8 (163) | 6.4 (19.9) | 67.5 (311.3) | 71 (19.3) |
| >450 ms (n = 52) | 2.3 [1.3–4.0] | 188.4 (375.6) | 8.3 (25.5) | 75.1 (280.7) | 9 (17.3) | |
| QRS duration | ≤120 ms (n = 376) | 1.4 [1.1–1.7] | 90.3 (211.4) | 6.4 (20.1) | 62.6 (298.7) | 73 (19.4) |
| >120 ms (n = 43) | 2.6 [1.4–4.8] | 84.8 (132.5) | 8.6 (25.5) | 119.3 (374.5) | 7 (16.3) | |
| QRS-T angle | <100° (n = 383) | 1.6 [1.3–1.9] | 90.9 (209) | 6.8 (21.3) | 69.2 (312.7) | 73 (19.1) |
| ≥100° (n = 36) | 1 [0.5–1.9] | 77.7 (151.1) | 5.3 (13) | 59.9 (245.9) | 7 (19.4) |
Crude cumulative AF burden was calculated as cumulative AF duration in the negative binomial model with the total monitoring duration as offset. IAB was defined as P-wave duration ≥120 ms combined with the presence of biphasic P-wave (positive–negative) in any inferior lead. QTc interval was estimated using the Framingham formula.
Missing observations: PR interval, n = 2; P-wave duration, n = 3; P-wave voltage in Lead I, n = 5; P-wave axis, n = 10, P-wave terminal force in Lead V1, n = 5; IAB, n = 3.
Abbreviations: AF, atrial fibrillation; CI, confidence interval; ECG, electrocardiogram; IAB, interatrial block; QTc, heart rate-corrected QT interval; SD, standard deviation.