junctional rhythms Flashcards
junctional rhythm
rate: 40-60bpm rythm- regular P wave: none, antegrade, retrograde P:QRS ratio: 1:1 or retrograde PR internal- non, short or retrograde QRS width- 120ms (0.12 sec)
normal rhythms of different areas
SA node (60-100 bpm)
Atria (< 60 bpm)
AV node (40-60 bpm)
Ventricles (20-40 bpm)
different junctional rhythms:
Junctional bradycardia = junctional rhythm at a rate of < 40 bpm.
Junctional escape rhythm = junctional rhythm at a rate of 40-60 bpm.
Accelerated junctional rhythm = junctional rhythm at 60-100 bpm.
Junctional tachycardia = junctional rhythm at > 100 bpm.
accelerated junctional rhtyhm
rate: 60-100 rythm- regular P wave: none, antegrade, retrograde P:QRS ratio: 1:1 or retrograde PR internal- non, short or retrograde QRS width- 120ms (0.12 sec)
junctional tachcardia
rate: >100bpm rythm- regular P wave: none, antegrade, retrograde P:QRS ratio: 1:1 or retrograde PR internal- non, short or retrograde QRS width- 120ms (0.12 sec)
supraventricular tachycardia- AVNRT
Regular tachycardia ~140-280 bpm.
QRS complexes usually narrow (< 120 ms) unless pre-existing bundle branch block, accessory pathway, or rate related aberrant conduction.
ST-segment depression may be seen with or without underlying coronary artery disease.
QRS alternans – phasic variation in QRS amplitude associated with AVNRT and AVRT, distinguished from electrical alternans by a normal QRS amplitude.
P waves if visible exhibit retrograde conduction with P-wave inversion in leads II, III, aVF.
P waves may be buried in the QRS complex, visible after the QRS complex, or very rarely visible before the QRS complex.