Abstract 14455: A New 4-Variable Formula to Differentiate Early Repolarization From Subtle Left Anterior Descending Coronary Occlusion -- Adding QRS Amplitude of V2 Improves the Model

Introduction: Precordial normal variant ST elevation (STE), or “early repolarization” (ER), may be difficult to differentiate from subtle ischemic STE due to LAD occlusion. We previously derived and validated a logistic regression tool that was far superior to STE alone for differentiating the two on the ECG. The tool uses R-wave amplitude in lead V4 (RAV4), ST elevation at 60 milliseconds after the J-point in lead V3 (STE60V3) and the computerized Bazett-corrected QT interval (QTc). The 3-variable formula is: 1.196 x STE60V3 + 0.059 x QTc – 0.326 x RAV4 with a cutpoint of 23.4. Hypothesis: Adding QRS voltage in V2 (QRSV2) would improve the accuracy of the formula. Methods: Of 355 consecutive LAD occlusions, non-obvious (subtle) ones were studied and “obvious” ones were excluded: one straight or convex ST segment in V2-V6, any ST depression, Q-waves, “terminal QRS distortion,” or any ST elevation > 5 mm. ER group were emergency department patients with chest pain who ruled out for acute MI by serial tropo...