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Bidirectional Ventricular Tachycardia (VT)

Bidirectional ventricular tachycardia (BVT)

Ventricular Tachycardia
Bidirectional Ventricular Tachycardia
ECG and Bidirectional Ventricular Tachycardia

Ventricular Tachycardia

Unifocal ventricular tachycardia, one ectopic ventricular focus, electrical ventricular vector, ventricular activation

Ventricular Tachycardia (VT) has a ventricular ectopic focus

Below the His bundle
Generates specific signs on the ECG

The focus generates impulses with a frequency > 100/min.

Mechanism of impulses can be:

Re-entry (most common)
Increased automaticity
Triggered activity

Produces wide QRS complexes (>0.12s)

Rarely, QRS complexes are narrow (VT from the ventricular septum area, Fascicular VT)

A ventricular ectopic focus generates a ventricular electrical vector

Which then depolarizes the ventricles and produces QRS complexes

Bidirectional Ventricular Tachycardia

Bidirectional Ventricular Tachycardia

Bidirectional Ventricular Tachycardia is a polymorphic ventricular tachycardia
It involves 2 ectopic foci in the ventricles

Which alternately generate impulses

Ventricular Extrasystole (VES)

In the right ventricle triggers a VES in the left ventricle

This pattern repeats continuously (ping-pong theory)
On the ECG, QRS complexes rotate

In the frontal plane in two directions (180°)

The mechanism is early afterdepolarization
Bidirectional Ventricular Tachycardia occurs

Most commonly in digoxin toxicity
The second most common cause is Catecholaminergic Polymorphic VT
Andersen-Tawil Syndrome
Metastatic heart involvement
Poisoning by plants of the genus Aconite (Aconite poisoning)

Bidirectional Ventricular Tachycardia is not ventricular bigeminy

In ventricular bigeminy, sinus rhythm alternates with ventricular extrasystole in a 1:1 ratio
In bidirectional ventricular tachycardia, 2 ventricular extrasystoles alternate in a 1:1 ratio

ECG and Bidirectional Ventricular Tachycardia

Frequency > 100/min.
Wide QRS complexes > 0.12s
Cardiac axis shifts by approximately 180°

ECG Bidirectional ventricular tachycardia (BVT)

ECG Bidirectional ventricular tachycardia (BVT)

Bidirectional Ventricular Tachycardia

Frequency: 130/min.
All QRS complexes are wide > 0.12s

Because they originate from the ventricles

Cardiac axis shifts approximately 180° with each beat
No P waves are present before the QRS complexes
The tachycardia occurred during physical exertion and the patient was not taking digoxin

This is catecholaminergic polymorphic ventricular tachycardia

ECG Ventricular Bigeminy

ECG premature ventricular complex (PVC), ventricular bigeminy

Ventricular Bigeminy

Bidirectional ventricular tachycardia is not present on the ECG because

After each sinus beat (narrow QRS complex with a P wave)
There is a ventricular extrasystole (wide QRS complex)

This is ventricular bigeminy

ECG digoxim toxicity, Bidirectional ventricular tachycardia (BVT)

Bidirectional Ventricular Tachycardia

Heart Rate: 130/min.
Wide QRS complexes (> 0.12s)
Heart Axis shifts approximately 180° (best observed on continuous lead II)
The patient was digitally intoxicated

This is why catecholaminergic polymorphic ventricular tachycardia is not present on this ECG

ECH exercise, Cathecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic Polymorphic Ventricular Tachycardia

This involves a young 20-year-old patient with no structurally damaged heart
During ergometry - cycling, the patient experienced ECG abnormalities and palpitations (heart pounding)

After 30 seconds of exertion, the ECG showed ventricular bigeminy
After 1 minute, paroxysms of bidirectional ventricular tachycardia appeared
After 4 minutes, the patient stopped cycling

A polymorphic ventricular tachycardia developed, which gradually started transitioning to a sinus rhythm

This is catecholaminergic polymorphic ventricular tachycardia

Bidirectional tachycardia occurred during physical exertion and resolved at rest
The patient was not overdosed on digoxin

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Bidirectional Ventricular Tachycardia (VT)

Bidirectional ventricular tachycardia (BVT)

Ventricular Tachycardia
Bidirectional Ventricular Tachycardia
ECG and Bidirectional Ventricular Tachycardia

Ventricular Tachycardia

Ventricular Tachycardia (VT) has a ventricular ectopic focus

Below the His bundle
Generates specific signs on the ECG

The focus generates impulses with a frequency > 100/min.

Mechanism of impulses can be:

Re-entry (most common)
Increased automaticity
Triggered activity

Produces wide QRS complexes (>0.12s)

Rarely, QRS complexes are narrow (VT from the ventricular septum area, Fascicular VT)

A ventricular ectopic focus generates a ventricular electrical vector

Which then depolarizes the ventricles and produces QRS complexes

Unifocal ventricular tachycardia, one ectopic ventricular focus, electrical ventricular vector, ventricular activation

Bidirectional Ventricular Tachycardia

Bidirectional Ventricular Tachycardia is a polymorphic ventricular tachycardia
It involves 2 ectopic foci in the ventricles

Which alternately generate impulses

Ventricular Extrasystole (VES)

In the right ventricle triggers a VES in the left ventricle

This pattern repeats continuously (ping-pong theory)
On the ECG, QRS complexes rotate

In the frontal plane in two directions (180°)

The mechanism is early afterdepolarization
Bidirectional Ventricular Tachycardia occurs

Most commonly in digoxin toxicity
The second most common cause is Catecholaminergic Polymorphic VT
Andersen-Tawil Syndrome
Metastatic heart involvement
Poisoning by plants of the genus Aconite (Aconite poisoning)

Bidirectional Ventricular Tachycardia

Bidirectional Ventricular Tachycardia is not ventricular bigeminy

In ventricular bigeminy, sinus rhythm alternates with ventricular extrasystole in a 1:1 ratio
In bidirectional ventricular tachycardia, 2 ventricular extrasystoles alternate in a 1:1 ratio

ECG and Bidirectional Ventricular Tachycardia

Frequency > 100/min.
Wide QRS complexes > 0.12s
Cardiac axis shifts by approximately 180°

ECG Bidirectional ventricular tachycardia (BVT)

Bidirectional Ventricular Tachycardia

Frequency: 130/min.
All QRS complexes are wide > 0.12s

Because they originate from the ventricles

Cardiac axis shifts approximately 180° with each beat
No P waves are present before the QRS complexes
The tachycardia occurred during physical exertion and the patient was not taking digoxin

This is catecholaminergic polymorphic ventricular tachycardia

ECG Bidirectional ventricular tachycardia (BVT)

ECG premature ventricular complex (PVC), ventricular bigeminy

Ventricular Bigeminy

Bidirectional ventricular tachycardia is not present on the ECG because

After each sinus beat (narrow QRS complex with a P wave)
There is a ventricular extrasystole (wide QRS complex)

This is ventricular bigeminy

ECG Ventricular Bigeminy

ECG digoxim toxicity, Bidirectional ventricular tachycardia (BVT)

Bidirectional Ventricular Tachycardia

Heart Rate: 130/min.
Wide QRS complexes (> 0.12s)
Heart Axis shifts approximately 180° (best observed on continuous lead II)
The patient was digitally intoxicated

This is why catecholaminergic polymorphic ventricular tachycardia is not present on this ECG

ECH exercise, Cathecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic Polymorphic Ventricular Tachycardia

This involves a young 20-year-old patient with no structurally damaged heart
During ergometry - cycling, the patient experienced ECG abnormalities and palpitations (heart pounding)

After 30 seconds of exertion, the ECG showed ventricular bigeminy
After 1 minute, paroxysms of bidirectional ventricular tachycardia appeared
After 4 minutes, the patient stopped cycling

A polymorphic ventricular tachycardia developed, which gradually started transitioning to a sinus rhythm

This is catecholaminergic polymorphic ventricular tachycardia

Bidirectional tachycardia occurred during physical exertion and resolved at rest
The patient was not overdosed on digoxin

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers