Which of the following ECG findings is NOT part of the Sgarbossa criteria for diagnosing acute STEMI in the presence of left bundle branch block (LBBB)?

Explanation

## Sgarbossa Criteria for STEMI with LBBB **Key Point:** The Sgarbossa criteria were developed to identify acute STEMI in patients with pre-existing or new LBBB, where ST-segment changes are difficult to interpret due to baseline LBBB morphology. ### The Three Sgarbossa Criteria | Criterion | Finding | Points | |-----------|---------|--------| | **1. Concordant ST elevation** | ST elevation ≥1 mm in leads with upward (positive) QRS complex | 5 points | | **2. Concordant ST depression** | ST depression ≥1 mm in leads V1–V3 | 3 points | | **3. Excessively discordant ST elevation** | ST elevation ≥5 mm in leads with downward (negative) QRS complex | 2 points | **High-Yield:** A Sgarbossa score ≥3 points has 90% specificity for acute STEMI in LBBB. The three criteria above are the **only** validated findings. ### Why Option D Is Incorrect **Warning:** T wave inversion in lead aVL is **NOT** part of the Sgarbossa criteria. While T wave changes may occur in STEMI, they are not specific enough to be included in the diagnostic algorithm for LBBB. The Sgarbossa criteria focus exclusively on ST-segment changes (elevation or depression) in specific leads. **Clinical Pearl:** In patients with LBBB and acute chest pain, the presence of any single Sgarbossa criterion should raise suspicion for STEMI and warrant urgent angiography, as the sensitivity of standard ECG interpretation is very low in this population.