Table 1.
Comparison of clinical and electrocardiographic characteristics of participants on hemodialysis with QRS-T angle ≥75° and participants on hemodialysis with QRS-T angle <75°
| Characteristic | N | Overall, n=358 | QRS-T Angle <75°, n=152 | QRS-T Angle ≥75°, n=206 |
|---|---|---|---|---|
| Demographic and clinical characteristics | ||||
| Mean age (SD), yr | 358 | 55 (13) | 55 (14) | 55 (13) |
| Men, n (%) | 358 | 212 (59) | 83 (55) | 129 (63) |
| Black, n (%) | 358 | 262 (73) | 106 (70) | 156 (76) |
| Mean BMI (SD), kg/m2 | 357 | 29.5 (7.9) | 29.0 (0.7) | 29.8 (0.5) |
| Diabetes, n (%) | 358 | 207 (58) | 76 (50) | 131 (64) |
| Hypertension, n (%) | 358 | 358 (100) | 152 (100) | 206 (100) |
| Coronary artery disease, n (%) | 358 | 132 (37) | 48 (32) | 84 (41) |
| Family history of CHD, n (%) | 358 | 153 (43) | 68 (45) | 85 (41) |
| Family history of sudden death, n (%) | 358 | 35 (10) | 16 (11) | 19 (9) |
| Ever smoke, n (%) | 358 | 220 (61) | 89 (59) | 131 (64) |
| Ever alcohol use, n (%) | 354 | 287 (81) | 125 (83) | 162 (79) |
| β-Blocker, n (%) | 322 | 226 (70) | 90 (65) | 136 (74) |
| ACE inhibitor, n (%) | 322 | 110 (34) | 42 (30) | 68 (37) |
| Angiotensin receptor blocker, n (%) | 322 | 33 (10) | 13 (9) | 20 (11) |
| Calcium channel blocker, n (%) | 322 | 196 (61) | 85 (62) | 111 (60) |
| 3-mo Averaged calcium (SD), mg/dl | 358 | 8.6 (0.6) | 8.6 (0.6) | 8.6 (0.7) |
| 3-mo Averaged potassium (SD), mEq/L | 356 | 4.3 (0.4) | 4.3 (0.5) | 4.3 (0.4) |
| 3-mo Averaged magnesium (SD), mg/dl | 355 | 2.1 (5.3) | 2.4 (8.2) | 1.8 (0.2) |
| 3-mo Averaged albumin (SD), g/dl | 356 | 3.6 (0.5) | 3.6 (0.5) | 3.5 (0.5) |
| 3-mo Averaged creatinine (SD), mg/dl | 340 | 6.7 (2.4) | 6.7 (2.4) | 6.8 (2.4) |
| 3-mo Averaged intradialytic weight change (SD), kg | 349 | 2.3 (0.9) | 2.1 (0.9) | 2.4 (0.9) |
| Mean nondialysis seated systolic BP (SD), mmHg | 357 | 137.3 (24.6) | 132.5 (23.3) | 140.9 (24.9) |
| Mean nondialysis seated diastolic BP (SD), mmHg | 357 | 74.8 (14.8) | 71.9 (13.6) | 76.9 (15.3) |
| Dialysate calcium (%), mEq/La | 349 | |||
| 2 | 145 (41) | 67 (46) | 78 (38) | |
| 2.25 | 15 (4) | 5 (3) | 10 (5) | |
| 2.5 | 187 (54) | 72 (50) | 115 (56) | |
| 3 | 2 (1) | 1 (1) | 1 (1) | |
| Dialysate potassium (%), mEq/La | 350 | |||
| 1 | 4 (1) | 2 (1) | 2 (1) | |
| 2 | 294 (84) | 120 (82) | 174 (85) | |
| 3 | 52 (15) | 24 (17) | 28 (14) | |
| LV function by ECG | ||||
| Mean LV ejection fraction (SD) | 351 | 65.5 (12.0) | 66.0 (11.2) | 65.2 (12.6) |
| Mean LV mass index (SD), g/m2 | 349 | 146.3 (48.6) | 132.4 (37.7) | 156.7 (53.1) |
| Mean LV mass index (SD), g/m2.7 | 350 | 66.6 (22.3) | 60 (17.7) | 72 (23.9) |
| LVH,b n (%) | 350 | 262 (75) | 104 (69) | 158 (79) |
| Mean LV end diastolic diameter (SD), cm | 351 | 5.4 (0.7) | 5.3 (0.6) | 5.4 (0.7) |
| Mean LV end systolic diameter (SD), cm | 350 | 3.2 (0.8) | 3.1 (0.7) | 3.3 (0.8) |
| 12-Lead ECG characteristics | ||||
| Mean heart rate (SD), bpm | 306 | 71.4 (11.1) | 70.6 (10.6) | 72.1 (11.4) |
| Median heart rate variance (IQR), ms | 306 | 359 (122–1092) | 448 (149–1124) | 348 (119–1079) |
| Mean QTc (SD), ms | 306 | 484.6 (43.7) | 481.1 (46.8) | 487.3 (41.1) |
| Mean QRS duration (SD), ms | 358 | 100.4 (18.6) | 96.1 (14.4) | 103.6 (1.4) |
| Complete BBB, n (%) | 358 | 28 (8) | 6 (4) | 22 (11) |
| Mean spatial QRS-T angle (SD), ° | 358 | 90.4 (45.6) | 46.1 (18.9) | 123.0 (29.0) |
| SAECG characteristics | ||||
| Median filtered QRS duration (IQR), ms | 358 | 113 (106–124) | 111 (104.5–119.5) | 114 (107–128) |
| Median LAS40 (IQR) | 358 | 29 (20–37) | 31 (23–37) | 26 (19–38) |
| Median RMS40 (IQR) | 358 | 37.5 (23–26.6) | 37 (24.5–55) | 38 (23–60) |
| Median noise (IQR), μV | 358 | 0.3 (0.2–0.4) | 0.3 (0.2–0.3) | 0.3 (0.2–0.4) |
| Late potentials on SAECG, n (%) | 358 | 88 (25) | 35 (23) | 53 (26) |
BMI, body mass index; CHD, coronary heart disease; ACE, angiotensin-converting-enzyme; IQR, interquartile range; QTc, corrected QT interval; RMS40, root-mean-square voltage of the last 40 ms.
a
Closest to study clinic visit.
b
LVH defined as LV mass index >51 g/m2.7 in men and >47 g/m2.7 in women.