ECG findings in re-entrant tachycardias
Last reviewed 01/2018
The rhythm is regular and the rate is between 130 and 250 beats per minute.
The QRS complex is narrow unless:
- there is rate-related bundle branch block
- there is pre-existing bundle branch block
- anterograde conduction occurs down an accessory pathway which is distinct from the AV node
P waves:
- are inverted
- in AV-nodal re-entry tachycardia may be masked by the QRS complex
- in AV re-entry tachycardia occur half-way between the QRS complexes
- there is one P wave for each QRS complex