Regular Broad Complex Tachycardia: Differential Diagnosis and Management
| Arrhythmia | Comment | Management |
|---|---|---|
| Monomorphic ventricular tachycardia (Figure40.1) | Commonest cause and should be the default diagnosis (especially if there is a history of previous myocardial infarction or other structural heart disease) Restore sinus rhythm as soon as possible, even in haemodynamically stable patients, as sudden deterioration may occur | DC cardioversion (Chapter 121) if there is haemodynamic instability or other measures are ineffective In stable patient, DC cardioversion, IV antiarrhythmic therapy (Table 40.2), or antitachycardia pacing Refer to a cardiologist |
| Supraventricular tachycardia (SVT) with bundle branch block | Confirm with adenosine test (Table 42.3) | DC cardioversion (Chapter 121) if there is haemodynamic instability or other measures are ineffective In stable patient, IV adenosine, verapamil or beta blocker (Table 42.3) Record 12-lead ECG after sinus rhythm restored to check for pre-excitation (WPW syndrome) Refer to a cardiologist if episodes are frequent or severe or if pre-excitation is found |
| Antidromic tachycardia or pre-excited atrial flutter in WPW syndrome | These are rarely seen but should be considered in a young patient with known WPW syndrome who does not have structural heart disease | DC cardioversion Refer to a cardiologist |
| Pseudoventricular tachycardia (Figure40.2) | Caused by body movement and intermittent skin-electrode contact (‘toothbrush tachycardia’) No haemodynamic change during apparent ventricular arrhythmia | No action needed It is important to avoid misdiagnosis as ventricular tachycardia |
WPW, Wolff-Parkinson-White.