Introduction to Arrhythmias

From ECGpedia

Morphologic criteria to differentiate between SVT vs. VT in a wide complex tachycardia. This is part of the 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.

First look at the heart rate:

• >100 bpm = tachycardia
• <60 bpm = bradycardia
• are there extra beats? -> Ectopic Beats

Secondly it is important to assess the origin of the arrhythmia:

• If the QRS < 120ms (i.e. a narrow complex), then it is either a sinus arrhythmia, supraventricular rhythm or a junctional tachycardia. In tachycardias, this flowchart will lead to the right diagnosis.^[1]
• If the QRS > 120ms it is either a ventricular tachycardia or a supraventricular rhythm with additional bundle branch block. This is a challenging difficulty in arrhythmia diagnosis, therefore a flowchart might help, which incoporates the Brugada criteria for VT.^[2] Another method to discriminate VT from SVT has been proposed by Vereckei et al.^[3] In the editorial on that paper an excellent review is given on the subject by Dendi and Josephson.^[4]

[edit] References