Table 1.
Baseline Characteristics of MESA participants stratified by normal (< 75th percentile), borderline (75–95th percentile) and abnormal (≥95th percentile) QRS-T angle
| Variable | Normal (n=4741) | Borderline (n=1298) | Abnormal (n=329) |
|---|---|---|---|
| Mean QRS-T Angle | 14.9 ± 9.8 | 50.4 ± 11.9 | 104.3 ± 30.1 |
|
| |||
| Age, (years)* | 60.6 ± 9.9 | 65 ± 9.9 | 68.3 ± 9.6 |
|
| |||
| Race | |||
| • White | 38% | 37.6% | 38.3% |
| • Black | 27.7% | 27.1% | 27.1% |
| • Asian | 12.2% | 12.6% | 12.2% |
| • Hispanic | 22.1% | 22.7% | 22.5% |
|
| |||
| Female sex | 53.8% | 53.5% | 54.4% |
|
| |||
| Smoker | 13% | 13.4% | 13.1% |
|
| |||
| Systolic BP, (mm Hg) | 124.5 ± 20.9 | 130.2 ± 21.9 | 138.6 ± 21.9 |
|
| |||
| Diastolic BP, (mm Hg) | 71.6 ± 10.1 | 72.3 ± 10.5 | 74.6 ± 11.3 |
|
| |||
| Body mass index, (kg/m2) | 28.2 ± 5.4 | 28.4 ± 5.6 | 28.9 ± 6.0 |
|
| |||
| Waist:Hip Ratio | 0.92 ± 0.08 | 0.94 ± 0.08 | 0.95 ± 0.07 |
|
| |||
| Total cholesterol, (mg/dL) | 194.6 ± 36.2 | 193.7 ± 34 | 194.9 ± 35.3 |
|
| |||
| HDL-cholesterol, (mg/dL) | 51.3 ± 14.8 | 50.2 ± 14.7 | 51 ± 14.9 |
|
| |||
| LDL-cholesterol, (mg/dL) | 117.5 ± 31.8 | 117.2 ± 30.1 | 116.6 ± 32.8 |
|
| |||
| Triglycerides, (mg/dL) | 130.6 ± 91.9 | 134.3 ± 82.5 | 136.9 ± 78.2 |
|
| |||
| Glucose, (mg/dL) | 96.2 ± 29.9 | 99.8 ± 30.5 | 102 ± 33.6 |
|
| |||
| Creatinine (mg/dl) | 0.94 ± 0.2 | 0.97 ± 0.3 | 1.0 ± 0.3 |
|
| |||
| Diabetes Mellitus | 11.2% | 15.7% | 17.7% |
|
| |||
| Treatment for hypertension | 30% | 38.8% | 46.8% |
|
| |||
| Treatment for hyperlipidemia | 15.2% | 17.8% | 19.5% |
|
| |||
| Physical Activity (MET- min/wk) | 6020 ± 6216 | 5183 ± 4933 | 4604 ± 5210 |
|
| |||
| Common Carotid IMT (mm) | 0.85 ± 0.19 | 0.90 ± 0.21 | 0.94 ± 0.21 |
|
| |||
| QRS (msec) | 91.2 ± 9.5 | 92 ± 10.3 | 93.5 ± 10.5 |
|
| |||
| QTc (msec) | 416.1 ± 20.2 | 420 ± 20.6 | 425.8 ± 24.6 |
|
| |||
| Heart Rate Variability (rmsdd1) (NS) | 26.8 ± 21.7 | 26.4 ± 25.7 | 26.7 ± 31.6 |
|
| |||
| Minor and Major ST abnormalities (Minnesota Code 4-1,4-2,4-3,4-4) | 2.3% | 7.2% | 37.4% |
|
| |||
| Minor and Major T wave abnormalities (Minnesota Code 5-1,5-2,5-3,5-4) | 6.1% | 23.6% | 64.1% |
|
| |||
| Major ECG abnormality (Minnesota Code) | 5.8% | 11% | 44% |
|
| |||
| Minor ECG abnormality (Minnesota Code) | 31.6% | 48.9% | 69.3% |
|
| |||
| ECG-LVH‡ | 0.4% | 0.9% | 10.3% |
|
| |||
| Coronary artery calcium > 0 | 45.9% | 56.6% | 68.4% |
Abbreviations:
BP = Blood Pressure, HDL = High density lipoprotein, LDL = Low density lipoprotein, IMT = intima-medial thickness, LVH = left ventricular hypertrophy
*
Means ± Standard deviation unless otherwise indicated
†
Defined as self-reported “yes” or fasting glucose ≥126 mg/dL
‡
Cornell voltage (CV) > 2200μV for women; > 2800μV for men