Differential diagnosis of tachycardia

Broad complex tachycardia must always be presumed to originate from the ventricles unless reliably shown otherwise. Ventricular tachycardia (VT) must not be misdiagnosed as supraventricular tachycardia (SVT) – a misdiagnosis the other way round is not as dangerous . After emergency treatment, a patient with broad complex tachycardia must be referred for a specialist assessment. The referral letter should include a detailed medical history and a copy of an ECG recording taken both during the tachycardia and during normal rhythm.