Wide complex tachycardias (WCT) are characterized by QRS widths greater than 0.12 s on an ECG. They are often, but not always, synonymous with ventricular tachycardia (VT), which is a period of three or more ventricular originated beats at a rate ≥ 100/minute. VT can be either monomorphic or polymorphic in nature.
The objective of care is the rapid termination of life-threatening ventricular tachycardia. Electrical cardioversion is the safest, most reliable mechanism to convert VT into a stable perfusing rhythm.
Although WCT can develop primarily, it is often a sign of an underlying clinical condition, such as ischemia, hypoxia, hyperkalemia, or increased sympathetic tone. A thorough history should be performed prior to formulating a management plan and any underlying conditions should be considered and addressed concurrently with the tachycardia.
Consider as unstable any patient with WCT and any of:
Altered or rapidly falling level of consciousness
Systolic blood pressure < 90 mmHg
Ischemic chest pain
Significant shortness of breath or signs of cardiogenic pulmonary edema
WCTs are generally regular. Some irregularity can be normal in ventricular tachycardia, but consistently irregular wide complex rhythms should prompt consideration of a rhythm that is atrial in origin, usually atrial fibrillation, in conjunction with a bundle branch block.
Note that this must be distinguished from polymorphic WCT or torsades de pointes, where the morphology of each QRS complex is different and the R-R interval continues to change
A small percentage of regular, WCTs are actually supraventricular in origin and result from an aberrantly conducted electrical impulse. However, the vast majority are, and should be managed as, ventricular tachycardia.
First Responder (FR) Interventions
Keep the patient warm and protect from further heat loss
Place the patient in a position of comfort, as permitted by clinical condition; in general, limit patient movement