| Electrocardiographic signs | Workforce | Percentage |
| Sinus tachycardia | 21 | 65.6 |
| Left atrial hypertrophy | 9 | 28.1 |
| Left ventricular hypertrophy | 6 | 18.8 |
| Atrial flutter | 1 | 3.1 |
| Atrial fibrillation | 1 | 3.1 |
| Left bundle branch bloc | 1 | 3.1 |
| Others | 8 | 25 |