Table 3.
Distribution of ECG variables and chi-square analysis according to LVEF in the derivation cohort.
| ECG variables | LVEF ≥ 40% | LVEF <40% | P-value | |
|---|---|---|---|---|
| (n = 286) | (n = 67) | |||
| Q wave ≥ 2 contiguous leads | yes | 72 | 25 | 0.045 |
| no | 214 | 42 | ||
| Atrial fibrillation | yes | 10 | 8 | 0.005 |
| no | 276 | 59 | ||
| STD ≥ 1 mm in ≥ 2 contiguous leads | yes | 79 | 35 | <0.001 |
| no | 207 | 32 | ||
| PRWP | yes | 53 | 35 | <0.001 |
| no | 233 | 32 | ||
| Low voltage | yes | 12 | 6 | 0.111 |
| no | 274 | 61 | ||
| HR > 100 bpm | yes | 31 | 28 | <0.001 |
| no | 255 | 39 | ||
| QRS duration > 110 ms* | yes | 22 | 23 | <0.001 |
| no | 264 | 44 | ||
| LVH | yes | 33 | 11 | 0.276 |
| no | 253 | 56 | ||
| LAE | yes | 9 | 7 | 0.010 |
| no | 277 | 60 |
ECG, electrocardiography; LVEF, left ventricular ejection fraction; STD, ST-segment depression; PRWP, poor R wave progression; HR, heart rate; LVH, left ventricular hypertrophy; LAE, left atrial enlargement.
*
QRS duration > 110 ms included 24 complete right bundle branch blocks (53.3%), 7 complete left bundle branch blocks (15.6%) and 14 non-specific intraventricular conduction delays (31.1%).