Table 1.
Electrocardiographic parameters used to define various ECG abnormalities in the European Society of Cardiology recommendations, Seattle Criteria and Refined Criteria
| ECG abnormality | European Society of Cardiology (ESC) recommendations | Seattle Criteria | Refined Criteria |
|---|---|---|---|
| Left atrial enlargement | Negative portion of the P-wave in lead V1 ≥0.1 mV in depth and ≥40 ms in duration | Prolonged P-wave duration of >120 ms in leads I or II with negative portion of the P-wave ≥0.1 mV in depth and ≥40 ms in duration in lead V1 | As ESC |
| Right atrial enlargement | P-wave amplitude ≥2.5 mm in leads II, III or aVF | As ESC | As ESC |
| Left QRS-axis deviation | −30° to −90° | As ESC | As ESC |
| Right QRS-axis deviation | >115° | >120° | As ESC |
| RV hypertrophy | Sum of R-wave in V1 and S-wave in V5 or V6 ≥1.05 mV | Sum of R-wave in V1 and S-wave in V5>1.05 mV and right axis deviation >120O | As ESC |
| Corrected QT interval | >440 ms (men) and >460 ms (women) | >470 ms (men) and 480 ms (women) | As Seattle |
| Complete left bundle branch block | QRS ≥120 ms predominantly negative QRS complex in lead V1 (QS or rS), and upright monophasic R-wave in leads I and V6 | As ESC | As ESC |
| Complete right bundle branch block | RSR pattern in anterior precordial leads with QRS duration ≥120 ms | Not relevant | As ESC |
| Intraventricular conduction delay | Any QRS duration >120 ms including RBBB and LBBB | Any QRS duration ≥140 ms or complete LBBB | As ESC |
| Pathological Q-wave | >0.4 mV deep in any lead except III, aVR | >0.3 mV deep and/or >40 ms duration in ≥2 leads except III and aVR | ≥40 ms in duration or ≥25% of the height of the ensuing R-wave |
| Significant T-wave inversion | ≥2 mm in ≥2 adjacent leads (deep)or ‘minor’ in ≥2 leads | >1 mm in depth in two or more leads V2−6, II and aVF or I and aVL (excludes III, aVR and V1) | As Seattle |
| ST-segment depression | ≥0.5 mm deep in ≥2 leads | As ESC | As ESC |
| Ventricular pre-excitation | PR interval <120 ms with or without delta wave | PR interval <120 ms with delta wave | As Seattle |
LBBB, left bundle branch block; mm, millimetres; ms, milliseconds; RBBB, right bundle branch block.