Ventricular tachycardia electrocardiogram

EKG Findings

Ventricular tachycardia in Lead II (rhythm)

1. Abnormal and wide QRS complexes with secondary ST segment and T wave changes.
   
   • Usual QRS duration is > 0.12 seconds, may be shorter if the ectopic focus is located in the ventricular septum.
   • The secondary ST segment and T wave changes are in a direction that is opposite the major deflection of the QRS.
   • A ventricular rate between 140 and 200 BPM.
   • When the rate is >200 and has a sine wave appearance, it is called ventricular flutter.
   • When the rate is <110 BPM it is called non-paroxysmal VT.
2. A regular or slightly irregular (up to 0.03 seconds) rhythm.
   
3. Abrupt onset and termination.
   
4. AV dissociation.
   
   • Atrial rate slower than ventricular rate.
   • No relationship between atrial activity and ventricular activity.
   • There can be VA conduction.

     1. The RP interval is >0.11 seconds.
     2. Occurs in about 50% of cases.
     3. Uncommon when the ventricular rate is rapid (only 1/7 when the rate was>200).

5. Capture beats.
   
   • Occurs when a supraventricular impulse is conducted and captures the ventricle.
   • They are rare.
6. Fusion beats.
   
   • Rare in VT at a rapid rate.

Examples of Ventricular Tachycardia:

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  12 lead EKG: Ventricular tachycardia.

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  12 lead EKG: Ventricular tachycardia. Image courtesy of Dr Jose Ganseman

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  12 lead EKG: Ventricular tachycardia. Image courtesy of Dr Jose Ganseman

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  12 lead EKG: Ventricular tachycardia. Image courtesy of Dr Jose Ganseman

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  12 lead EKG: Ventricular tachycardia. Image courtesy of Dr Jose Ganseman

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  12 lead EKG: Ventricular tachycardia. Image courtesy of Dr Jose Ganseman

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  Ventricular tachycardia of 140 bpm with a left bundle branch block pattern and left heart axis.

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  Ventricular tachycardia of 250 bpm with a right bundle branch block pattern and right heart axis.

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  Ventricular tachycardia of 150 bpm with a right bundle branch block pattern and right heart axis. Note the 5th and 6th complex from the right side. These are fusion complexes.

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  Ventricular flutter on a 12 lead ECG

Differential Diagnosis of Underlying Causes of Ventricular Tachycardia

• Caffeine
• Cardiomyopathy
• Cocaine
• Congenital Heart Disease
• Congestive heart failure
• Electrolyte imbalance
• Hypertrophic cardiomyopathy
• Hypocalcemia
• Hypokalemia
• Hypomagnesia
• Iatrogenic due to pulmonary artery catheter, right heart catheterization, or electrophysiologic sutdy
• Methamphetamine
• STEMI
• Ventricular aneurysm