Sinus Dysrhythmia (Arrhythmia) - Course # 313-7


sinus arrhythmia tracing
  • Sinus Dysrhythmia often occurs as a normal variant. It is commonly seen in young healthy people and athletes. It is frequently related to breathing and pressure on the vagus nerve. As the patient inhales and the lungs expand, pressure is applied to the vagus nerve which causes a parasympathetic response and a decrease in heart rate.
  • Sinus Dysrhythmias may also occur as a result of medication effects or diseases such as multiple sclerosis.
  • This dysrhythmia often requires no treatment, but may require medication or therapy such as a pacemaker to regulate the heart rate if the ventricular response becomes too slow.
  • Sinus Dysrhythmia closely resembles Normal Sinus Rhythm with the only distinction being the intervals from one cardiac complex to the next are changing as influenced by the patients respiratory pattern.
  • Note the changing R to R Intervals.

Practice Strip

Sinus Tachycardia - Practice Strip

sinus dysrhythmia tracing
  • Analyze this tracing using the five steps of rhythm analysis.
  • Compare your answers with the answers on the next slide.


Practice Strip - Answers

sinus dysrhythmia tracing
  • Rhythm: Irregular
  • Rate: 60 bpm
  • P wave: upright and uniform
  • PR interval: 0.16 sec
  • QRS: 0.10 sec
  • Interpretation: Sinus Dysrhythmia

313 Sinus Dysrhythmia (Arrhythmia) - Course # 313-7