TABLE 1.
Clinical, anthropometric, and ECG data (features) used as inputs to the machine learning (ML) model
| Feature | Description, Units/Classes | Range | Mean/Mode |
|---|---|---|---|
| Sex | Male/Female | 2 | F |
| Age | Age, years | 31–90 | 61.5 |
| Hypertension | History of hypertension* | 2 | 1 |
| BMI group | Body mass index class** | 3 | 3 |
| Height | Height, cm | 137.0–194.0 | 165 |
| BSA | Body surface area, m2 | 1.3–2.8 | 1.93 |
| P duration | P wave duration, ms | 0.0–154.0 | 113 |
| QRS duration | QRS interval duration, ms | 68.0–138.0 | 92.7 |
| QTc duration | QT‐interval corrected for heart rate***, ms | 368.0–510.0 | 422 |
| ST duration | ST segment duration, ms | 0.0–277.0 | 112 |
| S amplitude (V1) | S wave amplitude in V1, mV | 0.0–1.9 | 0.732 |
| SL | Sokolow‐Lyon voltage, mV | 0.5–4.5 | 1.93 |
| R amplitude max | Tallest R wave in limb leads, mV | 0.3–1.9 | 0.903 |
| BMI/SL | BMI divided by SL voltage, kg/m2mV | 6.0–73.8 | 17.4 |
| ID (V5) | Intrinsicoid deflection in V5, ms | 24.0–57.0 | 39.5 |
| Area R (aVF) | Area under R wave in aVF, ms·mv | 0.0–21.3 | 3.46 |
| Area S (V1) | Area under S wave in V1, ms·mv | 0.0–62.2 | 17.3 |
| Area QRS (V5) | Area under QRS interval in V5, ms·mv | 11.0–80.2 | 33.7 |
| Area QRS (12) | Total area in all leads (sum), ms·mv | 137.5–672.9 | 285 |
| R amplitude (V2) | R wave amplitude in V2, mV | 0.0–2.0 | 0.41 |
| Cornell product | [R(aVL)+S(V3)]xQRS duration, ms·mv | 3.6–243.8 | 52.6 |
| S amplitude (V2) | S wave amplitude in V2, mV | 0.1–2.3 | 0.784 |
| S amplitude (V5) | S wave amplitude in V5, mV | 0.0–1.3 | 0.381 |
| QRS‐T angle | Planar Frontal QRS‐T angle, degrees | 0.0–176.0 | 33.3 |
| QRS axis front | QRS axis front, degrees | −77.0–97.0 | 15.6 |
| T axis front | T axis front, degrees | −59.0–258.0 | 39.8 |
| T amplitude (aVL) | T wave amplitude in aVL, mV | −0.3–0.3 | 0.0815 |
| T amplitude (V2) | T wave amplitude in V2, mV | −0.3–1.2 | 0.253 |
| J point (V5) | J point deflection, mV | −0.2–0.1 | −0.0422 |
| R‐S vector ratio | R‐S vector ratio V5/V2 | 0.0–118.0 | 5.41 |
| S amplitude (V3) | S wave amplitude in V3, mV | 0.1–2.7 | 0.828 |
| Cornell sum | R (aVL) + S (V3), mV | 0.2–3.8 | 1.39 |
*
0 = no history of hypertension, 1 = history of hypertension
**
Classes are: normal weight, overweight, obese
***
Calculated using the Bazett formula: , where QTc (ms), QT (ms), (unitless)