Introduction to Arrhythmias

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
• If the QRS > 120ms it is either a ventricular tachycardia or a supraventricular rhythm with additional bundle branch block

Normal heart rhythm is explained in:

• Sinus node rhythms and arrhythmias

Non-normal heart rhythms (arrhythmias) are described in:

• Supraventricular Rhythms
• Junctional Tachycardias
• Ventricular Arrhythmias
• AV Conduction
• Genetic Arrhythmias
• Pacemaker

• Flowchart: Approach to the Wide Complex Tachycardia
• Flowchart: Approach to the Narrow Complex Tachycardia Adapted from ESCnarrowQRS.

References

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1. ESCnarrowQRS pmid=14563598

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