Sinus Arrhythmia

Sinus arrhythmia (synonym: sinus arrhythmia; ICD-10 #D156: sinus arrhythmia) is a cardiac arrhythmia that belongs to the group of impulse formation disorders.

The sinus node (nodus sinuatrialis; synonyms: sinuatrial node (SA node) or Keith-Flack node) is the primary pacemaker center of the heart (= sinus rhythm). It is located in the region of the right ear of the heart near the suclus terminalis (depression that runs between the insertion of the superior and inferior vena cava).

At rest in adult humans, the sinus node produces a rate of 60-80 heartbeats/min.

In the context of sinus arrhythmia, the following forms are distinguished:

  • Respiratory sinus arrhythmia (RSA) – physiological fluctuation of heart rate, due to respiration (respiratory synchronous fluctuation of heart rate):

    Respiratory arrhythmia is a normal finding, most pronounced in children and adolescents.

  • Non-respiratory sinus arrhythmia – here there is damage to the sinus node; rare form; it may indicate heart disease such as coronary artery disease (CAD; coronary artery disease) or occurs in the context of sick sinus syndrome (sinus node disease).

Course and prognosis: sinus arrhythmia is usually physiologically caused by respiration (= respiratory sinus arrhythmia). In non-respiratory sinus arrhythmia, the focus is on therapy of the underlying disease.