Table 1: Published Algorithms and Their Predictive Value for Differentiating Left Ventricular Outflow Tract from Right Ventricular Outflow Tract Ventricular Arrhythmia.
| Author | n | Algorithm Used | Predictive Value |
| Ouyang et al. 2002[12] | 15 | R/S amplitude index (>0.5) and R duration index (>0.3) predict LVOT | Statistically significant difference between LVOT and RVOT origins |
| Ito et al. 2003[18] | 168 | Precordial R wave transition, QRS morphology in lead I, R wave duration index, R/S wave amplitude index in V1, V2 | Sensitivity 88% Specificity 95% |
| Yoshida et al. 2011[19] | 112 | TZ index <0 predicts LVOT | Sensitivity 88% Specificity 82% |
| Betensky et al. 2011[20] | 61 | V2 transition ratio ≥0.6 predicts LVOT origin | Sensitivity 95% Specificity 100% |
| Yoshida et al. 2014[21] | 207 | V2S/V3R index ≤1.5 predicts LVOT origin | Sensitivity 89% Specificity 94% |
| Kaypakli et al. 2017[22] | 123 | V1-V2 S-R difference = (V1S + V2S) - (V1R + V2R). If >1.625, predicts RVOT origin | Sensitivity 95% Specificity 85% |
| He et al. 2018[23] | 695 | Combined TZ index and V2S/V3R, Y = -1.15 x TZ - 0.494 x (V2S/V3R). If ≥ -0.76, predicts LVOT origin | Sensitivity 90% Specificity 87% |
| Di et al. 2019[24] | 184 | V1–V3 transition index > -1.60 predicts RVOT origin | Sensitivity 93% Specificity 86% |
| Zhang et al. 2017[25] | 174 | V4/V8 index >2.28 predicts LVOT origin | Sensitivity 67% Specificity 96% |
| Cheng et al. 2018[26] | 191 | V3R/V7 ≥0.85 predicts LVOT origin | Sensitivity 87% Specificity 96% |
LVOT = left ventricular outflow tract; RVOT = right ventricular outflow tract; TZ = transition zone.