Lown Grade (Ventricular Ectopy)

The Lown grading system for ventricular ectopy on an ambulatory ECG (Holter) recording, by the frequency and form of the ventricular ectopic beats, grades 0-5 with a 4A/4B split.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Lown grade
4B - salvos (three or more consecutive)

Result: Lown grade 4B: salvos, three or more consecutive ventricular ectopic beats (a run of ventricular tachycardia).

The tool opens with these values already filled in. Replace them with your own.

What the result means

Grade 0
No ventricular ectopic beats.
Grade 1
Occasional, isolated beats: fewer than 30 per hour.
Grade 2
Frequent beats: 30 or more per hour.
Grade 3
Multiform (polymorphic) beats.
Grade 4A
Couplets: two consecutive beats.
Grade 4B
Salvos: three or more consecutive beats, a run of ventricular tachycardia.
Grade 5
The R-on-T phenomenon: an early beat on the preceding T wave.

What you enter

  • Lown grade
How this is calculated

Lown B, Wolf M. Approaches to sudden death from coronary heart disease. Circulation. 1971;44(1):130-142. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.