When wide QRS tachycardia is present on the electrocardiogram ECG, it is necessary to rapidly<unk> e whether it is caused by ventricular tachycardia (VT) or a supraventricular tachycardia (SVT) with aberrant conduction.  While the EKG provides the most reliable data to distinguish VT from SVT with aberrant conduction, the clinical history and the age of the patient may also provide additional discriminatory information regarding the cause of the wide QRS tachycardia.  While older patients with a prior history of myocardial infarction are more likely to have VT, young hemodynamically stable patients presenting with paroxysmal tachycardia are more likely to have SVT with aberrant conduction.  Nevertheless, the primary tool to<unk> e VT from SVT with aberrant conduction is the ECG.  There are several findings that are more common in ventricular tachycardia, and there are also more sophisticated electrophysiologic algorithms such as the Brugada and Vereckei algorithms that can be used to distinguish VT from SVT with aberrant conduction. The<unk>  of VT is more likely if: There is a history of myocardial infarction or structural heart disease, the electrical axis is -90 to -180 degrees (a “northwest” or “superior” axis), the QRS is > 140 msec, there is AV dissociation, there are positive or negative QRS<unk> es in all the precordial leads, and the morphology of the QRS<unk> es resembles that of a previous premature ventricular contraction (PVC).
Wide complex tachycardia differential diagnosis
Junctional tachycardia other diagnostic studies
Pulseless ventricular tachycardia other diagnostic studies
Wide complex tachycardia risk factors
Ventricular fibrillation differential diagnosis
Second degree AV block other diagnostic studies
Third degree AV block other diagnostic studies
Accelerated idioventricular rhythm differential diagnosis