What is QRS complex tachycardia?

Narrow QRS complex tachycardias are fast cardiac rhythms (generally more than 100 beats/min) with a QRS duration of 100 ms or less.

What causes wide QRS tachycardia?

Wide complex tachycardia is a dysrhythmia with a long list of potential causes that ranges from various arrhythmias, structural heart abnormalities, electrolyte disturbances, toxins, and many more.

What does widening QRS complex mean?

A “wide QRS complex” refers to a QRS complex duration ≥120 ms. Widening of the QRS complex is related to slower spread of ventricular depolarization, either due to disease of the His-Purkinje network and/or reliance on slower, muscle-to-muscle spread of depolarization.

Which Tachycardic rhythm has a wide QRS complex?

Wide QRS complex tachycardia can be originated by 3 main mechanisms1: Ventricular tachycardia (VT). Supraventricular tachycardia (SVT) with an aberrant conduction attributable to a preexisting bundle-branch block or functional bundle-branch block induced by the fast heart rate.

What is narrow QRS tachycardia?

A narrow QRS complex (<120 milliseconds) reflects rapid activation of the ventricles via the normal His-Purkinje system, which in turn suggests that the arrhythmia originates above or within the His bundle (ie, a supraventricular tachycardia).

What conditions are typically associated with wide QRS complexes?

Wide, bizarre QRS complexes of supraventricular origin are often the result of intraventricular conduction defect which usually occurs due to right or left bundle branch block. Wide QRS complexes may be seen in aberrant conduction, ventricular preexcitation and with a cardiac pacemaker.

What meds cause wide QRS?

Permanent transvenous pacemaker results in wide QRS complexes. Tricyclic antidepressant (TCA) overdose causes a WCT due to the quinidine-like effects of these drugs. The class IA sodium channel blocking activity widens the QRS complex, with tachycardia being part of the toxidrome caused by these agents.

Is wide QRS an emergency?

Wide QRS complex tachycardias (WCT) present significant diagnostic and therapeutic challenges to the emergency physician. WCT may represent a supraventricular tachycardia with aberrant ventricular conduction; alternatively, such a rhythm presentation may be caused by ventricular tachycardia.

What are examples of wide complex tachycardia?

Underlying diseases

How wide is QRS in V tach?

Ventricular tachycardia refers to a wide QRS complex heart rhythm — that is, a QRS duration beyond 120 milliseconds — originating in the ventricles at a rate of greater than 100 beats per minute. This can be hemodynamically unstable, causing severe hypotension, and can thus be life-threatening.