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Vereckei Algorithm

Vereckei Algorithm: A simplified, lead aVR-only algorithm to differentiate Ventricular Tachycardia (VT) from Supraventricular Tachycardia (SVT) with aberrancy.

Examine Lead aVR Only

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

When to Use

Differential diagnosis of wide complex tachycardia (WCT) where the underlying rhythm is unclear.
As a fast, single-lead (aVR) alternative to the 4-step Brugada criteria.
Particularly useful when precordial leads (V1-V6) are unavailable or difficult to interpret.

Clinical Caveat

Any wide complex tachycardia in an unstable patient should be treated as VT regardless of algorithm results. Synchronized cardioversion is the priority.

How it Works

Why lead aVR?

During SVT with bundle branch block, the initial activation of the ventricles occurs via the normal specialized conduction system, which typically moves AWAY from lead aVR (creating a negative QRS). In VT, activation often starts in the inferior/apical regions and moves TOWARD aVR, or is slowed by muscle-to-muscle conduction.

The 4 Steps

01
Presence of an initial R wave: Highly specific for VT.
02
Initial r or q wave width > 40 ms: Suggests slow muscle-to-muscle conduction diagnostic of VT.
03
Notch on the descending limb of a negative QRS: Indicates fragmented ventricular activation.
04
Vi/Vt ratio ≤ 1: Measures the velocity of initial activation (Vi) vs terminal activation (Vt) in the last 40ms. SVT is fast initially (Ratio > 1), VT is slow initially (Ratio ≤ 1).

Clinical Pearls

Accuracy vs Brugada

The Vereckei algorithm has shown slightly higher overall accuracy than Brugada in some head-to-head trials, mainly due to its better performance in diagnosing VT in patients with pre-existing bundle branch blocks or cardiomyopathy.

The Evidence

Original Publication

New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia.

Vereckei A et al. • Heart Rhythm.. 2008;5(1):89-98. The landmark paper introducing the 4-step aVR algorithm.

Last Comprehensive Review: 2026-07-17

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

When to Use

Differential diagnosis of wide complex tachycardia (WCT) where the underlying rhythm is unclear.
As a fast, single-lead (aVR) alternative to the 4-step Brugada criteria.
Particularly useful when precordial leads (V1-V6) are unavailable or difficult to interpret.

Clinical Caveat

Any wide complex tachycardia in an unstable patient should be treated as VT regardless of algorithm results. Synchronized cardioversion is the priority.

How it Works

Why lead aVR?

During SVT with bundle branch block, the initial activation of the ventricles occurs via the normal specialized conduction system, which typically moves AWAY from lead aVR (creating a negative QRS). In VT, activation often starts in the inferior/apical regions and moves TOWARD aVR, or is slowed by muscle-to-muscle conduction.

The 4 Steps

01
Presence of an initial R wave: Highly specific for VT.
02
Initial r or q wave width > 40 ms: Suggests slow muscle-to-muscle conduction diagnostic of VT.
03
Notch on the descending limb of a negative QRS: Indicates fragmented ventricular activation.
04
Vi/Vt ratio ≤ 1: Measures the velocity of initial activation (Vi) vs terminal activation (Vt) in the last 40ms. SVT is fast initially (Ratio > 1), VT is slow initially (Ratio ≤ 1).

Clinical Pearls

Accuracy vs Brugada

The Vereckei algorithm has shown slightly higher overall accuracy than Brugada in some head-to-head trials, mainly due to its better performance in diagnosing VT in patients with pre-existing bundle branch blocks or cardiomyopathy.

The Evidence

Original Publication

New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia.

Vereckei A et al. • Heart Rhythm.. 2008;5(1):89-98. The landmark paper introducing the 4-step aVR algorithm.

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

JAMAJul 21, 2026
PCOS Is Now Called PMOS

Clinical Context

We think this has broad domain relevance to Vereckei Algorithm (VT vs SVT).

Alzheimers & DementiaJul 15, 2026
Structural MRI across lifespan reveals differential thalamic trajectories in Down syndrome

Clinical Context

We think this has broad domain relevance to Vereckei Algorithm (VT vs SVT).

Alzheimers & DementiaJul 15, 2026
Correction to “Systemic piezo1 activation improves cerebrovascular function in Alzheimer's disease”

Clinical Context

We think this has broad domain relevance to Vereckei Algorithm (VT vs SVT).