MAGENT

Sgarbossa criteria: how the 5, 3 and 2 points add up

The Sgarbossa criteria score three ECG findings in left bundle-branch block (LBBB): concordant ST elevation of at least 1 mm scores 5, concordant ST depression of at least 1 mm in V1 to V3 scores 3, and discordant ST elevation of at least 5 mm scores 2. The total runs from 0 to 10, and the calculator flags whether it's 3 or more.

Not a medical device. Not a diagnosis or dosing recommendation.

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What are the Sgarbossa criteria?

They come from Elena B. Sgarbossa and colleagues, published in the New England Journal of Medicine in 1996 from the GUSTO-1 trial. Their abstract describes comparing the baseline ECGs of patients with LBBB and confirmed acute myocardial infarction against patients with chronic coronary artery disease and LBBB. Three ST-segment findings were combined into a scoring system from 0 to 10, which was then tested in a separate group of patients with chest pain and LBBB.

Magent's calculator is the original 1996 version. It isn't the Smith-modified rule.

This page explains the arithmetic and the >= 3 flag in the exact expression below. It doesn't say what a score means for a particular person.

The Sgarbossa formula

Sgarbossa = 5 if concordant ST elevation ≥1 mm
          + 3 if concordant ST depression ≥1 mm in V1, V2 or V3
          + 2 if discordant ST elevation ≥5 mm
maximum = 10
flag = true when the total is 3 or more

Exact expression the calculator uses:

Sgarbossa = 5*concordant_st_elevation_1mm + 3*concordant_st_depression_v1_v3 + 2*discordant_st_elevation_5mm; max 10; score_ge_3 iff total >= 3

What each finding means

InputFindingPoints
concordant_st_elevation_1mmST elevation of 1 mm or more in a lead where the QRS is positive (same direction)5
concordant_st_depression_v1_v3ST depression of 1 mm or more in V1, V2 or V33
discordant_st_elevation_5mmST elevation of 5 mm or more, opposite to the QRS2

How the score works

  1. Decide each finding true or false from the ECG.
  2. Add the points for each true finding: 5, 3 or 2.
  3. Check the flag. score_ge_3 is true when the total is 3 or more.

Inputs come from the user

All three inputs are true or false, and anything else is rejected with an error. Magent doesn't read or measure the ECG. The calculator returns the total, the maximum of 10, the score_ge_3 flag and a line for each finding.

Worked examples

These use Magent's own expected values for the calculator. Each line adds the findings in the order of the table above.

Example 1: no findings

  1. Score: 0 + 0 + 0 = 0.
  2. score_ge_3: false.

Example 2: concordant ST elevation alone

  1. Score: 5 + 0 + 0 = 5.
  2. score_ge_3: true.

Example 3: concordant ST depression in V1 to V3 alone

  1. Score: 0 + 3 + 0 = 3.
  2. score_ge_3: true, because 3 counts.

Example 4: discordant ST elevation alone

  1. Score: 0 + 0 + 2 = 2.
  2. score_ge_3: false.

Example 5: ST depression and discordant ST elevation

  1. Score: 0 + 3 + 2 = 5.
  2. score_ge_3: true.

Example 6: all three findings

  1. Score: 5 + 3 + 2 = 10, the maximum.
  2. score_ge_3: true.

History of the Sgarbossa criteria

The calculator cites Sgarbossa EB, Pinski SL, Barbagelata A and colleagues, New England Journal of Medicine, 1996 (volume 334, issue 8, pages 481–487), from the GUSTO-1 investigators. The abstract names the three criteria and the scoring system from 0 to 10.

When it's used

The 1996 paper looked at ECGs with left bundle-branch block, where the usual ST changes are harder to read, and tested the criteria in patients with chest pain and LBBB.

Where it's used

The criteria are read from an ECG. The 1996 paper built them from baseline ECGs in the GUSTO-1 trial, then tested them in a separate group of patients with acute chest pain and left bundle-branch block.

Who uses it

The person reading the ECG decides whether each finding is present. The calculator adds the points and sets the flag.

Limits of the calculation

  • It adds three weighted findings. It doesn't confirm or rule out a heart attack, and it isn't a reperfusion decision.
  • Each finding is a true/false you supply. Magent doesn't read the tracing.
  • It's the 1996 GUSTO-1 version, not the Smith-modified rule or its ST/S ratio.
  • This page doesn't say what to do with a score.

Clinical decisions belong to a qualified clinician who knows the patient.

Glossary

  • LBBB: left bundle-branch block, a delay in the electrical signal to the left side of the heart.
  • ST segment: the part of the ECG between the QRS complex and the T wave.
  • QRS complex: the main spike of each beat on the ECG.
  • Concordant: the ST shift goes the same direction as the QRS.
  • Discordant: the ST shift goes the opposite direction from the QRS.

Common mistakes

  • Giving every finding the same weight. They score 5, 3 and 2.
  • Treating 3 as below the flag. The flag is true at 3 or more.
  • Using the Smith ratio here. That's the modified rule, a separate calculator.
  • Counting ST depression outside V1 to V3. The 3-point finding is limited to V1, V2 and V3.

Source

Sgarbossa EB, Pinski SL, Barbagelata A, et al. N Engl J Med. 1996;334(8):481-487. DOI: 10.1056/NEJM199602223340801. PMID: 8559200

Frequently asked questions

How are the Sgarbossa criteria scored?

Concordant ST elevation of at least 1 mm scores 5, concordant ST depression of at least 1 mm in V1 to V3 scores 3, and discordant ST elevation of at least 5 mm scores 2. Add them for 0 to 10.

What does the >= 3 flag mean in the calculator?

It's true when the total is 3 or more and false otherwise, as in the exact expression. This page doesn't say what that means for a particular person.

What is the highest Sgarbossa score?

10, when all three findings are present.

Is this the Smith-modified Sgarbossa rule?

No. This is the 1996 version. The Smith-modified rule is a separate calculator.