Wide QRS Tachycardia (WQRST) in a Patient with a Pacemaker - Is this VT?

Image 1

Is this Ventricular Tachycardia?

The WQRST tachycardia is initiated by ventricular couplet. On the second wide QRS complex, distinct atrial activity can be seen. After that the PM delivers a stimulus to the ventricles and the tachycardia is initiated.

Image 2 -PMT (Pacemaker-Mediated Tachycardia) Initiation

This is an attempt to simplify initiation of a classic form PMT (ELT - endless loop tachycardia).

Pacemaker-Mediated Tachycardia

Pacemaker-mediated tachycardia is any undesired pacing rate caused by the pulse generator or by the interaction of the pacing system with the patient.

The following are well documented causes of PMT:

• Runaway pacemaker
• Sensor-driven tachycardia
• Exposure to MRI scanners
• Mypotential tracking
• Atrial arrhythmias
• Endless-loop tachycardia

Reference:

Ellenbogen e al. 2011Clincal Cardiac Pacing, Defibrillation, and Resynchronization Therapy (4th Ed). Saunders PA

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