Description

The term “broad complex tachycardia” (BCT) describes a group of cardiac arrhythmias with a ventricular rate in excess of 100 beats per minute and a QRS duration of 120ms or more (Figure 1). It is widely appreciated that such a classification encompasses arrhythmias, arising from a supraventricular source, despite their commoner presentation with a narrow QRS morphology, as well as those with a ventricular origin. Given that the presentation of supraventricular tachycardia (SVT) with a wide QRS pattern is relatively uncommon, and that it has a benign prognosis when compared with the alternative diagnosis, ventricular tachycardia (VT), it is somewhat surprising that misdiagnosis of this condition persists, with potentially catastrophic consequences for the patient.¹

Although numerous guidelines for the diagnosis of BCT exist, few are directly applicable to the acute presentation of such patients in the emergency room; many rely on complex electrocardiographic criteria, which are not only difficult to remember, but also difficult to use. The purpose of this article, therefore, is to present a pragmatic, simple and easily utilisable scheme to aid the therapeutic decision-making process in BCT in the acute situation.