[[Image:VT_SVT_LBBB_WCT.svg|thumb|300px|Morphologic criteria to differentiate between SVT vs. VT in a wide complex tachycardia. This is part of the [[media:wideQRS_tachycardia_flow.png|wide complex tachycardia flowchart]]]]
Arrhythmias (non-normal heart rhythms) can be a challenge
to the person who tries to understand them. But with a systematical approach, diagnosis is often less difficult than it seems at the beginning.
A good stepwise approach to
interprete the heart rhythm is to follow these steps:
*What is the '''ventricular [[Rate|heart rate]]'''?
**>100 bpm = tachycardia
** If the heart axis turns significantly when compared to the heart axis during sinus rhythm a ventricular origin of the rhythm is more likely.
* What is the '''clinical setting'''?
** A wide complex tachycardia in a hemodynamically
instable 70 year old man with previous myocardial infarction should be concidered a [[ventricular tachycardia]] until proven otherwise** A wide complex tachycardia in a 24 year old women with recurrent spells of tachycardia the respond to vagal manouevres is most likely an [[AVNRT]] with aberrant conduction.