From the Guidelines
The Sgarbossa criteria for diagnosing acute myocardial infarction include ST-segment elevation ≥1 mm in leads with a positive QRS complex, ST-segment depression ≥1 mm in leads V1, V2, or V3, and a modified criterion of ST elevation/depression divided by S-wave amplitude with a ratio ≤-0.25. The criteria are used to diagnose myocardial infarction in patients with left bundle branch block (LBBB) or ventricular paced rhythm. The original criteria assign points to each finding: ST-segment elevation ≥1 mm in leads with a positive QRS complex (5 points), ST-segment depression ≥1 mm in leads V1, V2, or V3 (3 points). A score of ≥3 points indicates likely myocardial infarction, as seen in patients with acute myocardial infarction presenting with st-segment elevation 1. Key points to consider when using the Sgarbossa criteria include:
- The criteria are valuable for rapidly identifying patients who need immediate reperfusion therapy despite having LBBB
- The criteria have good specificity but only moderate sensitivity, so clinical judgment remains important when evaluating patients with chest pain and LBBB
- Repeated ECG recordings are often needed to confirm the diagnosis, and elevated markers of myocardial necrosis, such as CK-MB and troponins, can also aid in diagnosis 1. It is essential to note that the provided evidence does not directly describe the Sgarbossa criteria, but the criteria are widely accepted and used in clinical practice for diagnosing acute myocardial infarction in patients with LBBB or ventricular paced rhythm.
From the Research
Sgarbossa Criteria
The Sgarbossa criteria are a set of electrocardiogram (ECG) criteria used to diagnose acute myocardial infarction (AMI) in patients with left bundle branch block (LBBB) [ 2, 3, 4, 5, 6 ].
Criteria
The criteria include:
- ST-segment elevation of 1 mm or more that is concordant with the QRS complex
- ST-segment depression of 1 mm or more in lead V1, V2, or V3
- ST-segment elevation of 5 mm or more that is disconcordant with the QRS complex [ 6 ]
Scoring System
A scoring system (0 to 10) was developed using these three criteria, allowing for a highly specific diagnosis of acute myocardial infarction to be made [ 6 ].
- A Sgarbossa score of 3 or more has been shown to have a high specificity and positive predictive value for acute myocardial infarction and angiography-confirmed acute coronary occlusion [ 4 ]
Clinical Application
The Sgarbossa criteria can be used to quickly and accurately identify patients with LBBB who have acute coronary artery occlusion, and who would benefit from reperfusion therapy [ 4 ].
- The criteria can also help reduce false catheterization laboratory activation and inappropriate fibrinolytic therapy [ 4 ]
Limitations
The Sgarbossa criteria are not perfect and should be used in conjunction with other diagnostic tools, such as serum biomarkers, to confirm the diagnosis of AMI in patients with LBBB [ 5 ].
- ECG alone is not sufficient to support the diagnosis of AMI, and elevated biochemical markers of myocardial necrosis are necessary to confirm the diagnosis [ 5 ]