Table 6. ECG features VA arising from RVOT and LVOT.
| Location of VA | BBB | Axis | Precordial transition | I | V1 | V6 | Other features |
| RVOT | |||||||
| Anteroseptal | LBBB | Inferior | ≤ V3 | rS | rS | R | Negative, isoelectric, or multiphasic I |
| Posterior, free Wall | LBBB | Inferior | ≥ V3 | R | rS | R | Positive I, broad late notched inferior leads |
| LVOT | |||||||
| Supravalvular | |||||||
| LCC | LBBB | Inferior | ≤ V2 | rS | rS, RS | R | QS or RS in lead I; notched M or W in V1 |
| RCC | LBBB | Inferior | ≤ V3 | R | rS, RS | R | Broad R in V2 |
| LCC/RCC junction | LBBB | Inferior | V3 | R/Rsr' | qrS | R | Notched on the downward deflection or W pattern in V1 |
| Infravalvular | |||||||
| AMC | RBBB | Inferior | Positive concordance | R/Rs | qR | R | No S in V6 |
| Septal-para-Hisian | LBBB | Left inferior | Early | Rs | QS, Qr | Rs | QS amplitude lead II/III ratio > 1 |
| Anterior interventricular great cardiac vein junction | LBBB | Inferior | Early | rS | rS, QS | R | Precordial pattern break, MDI > 0.55 |
With modifications from Della Rocca, et al.[18] AMC: aortomitral cotinuity; BBB: bundle branch block; ECG: electrocardiogram; LBBB: left bundle branch block; LCC: left coranary cusp; LVOT: left ventricular outflow tract; MDI: maximum deflection index; RBBB: right bundle branch block; RCC: right coronary cusp; RVOT: right ventricular outflow tract; VA: ventricular arrhythmia.