Pathogenesis (development of disease)
Respiratory sinus arrhythmia is a cardiac arrhythmia that is triggered by respiratory activity (an atemsynchronous variation in heart rate). During inspiration (inhalation), the heart rate becomes faster; during expiration (exhalation; esp. in younger, “vegetative” individuals), it becomes slower.Respiratory arrhythmia is a normal finding that is most pronounced in children and adolescents.In nonrespiratory sinus arrhythmia, there is damage to the sinus node; it may indicate heart disease such as coronary artery disease (CAD) or occurs as part of sick sinus syndrome.
Etiology (Causes)
Disease-related causes
- Damage to the sinus node caused by, for example, myocardial infarction (heart attack).
Medication
- Intoxication with digitalis glycosides – medications such as digoxin that strengthen the heart and are used to treat cardiac arrhythmias
Note: sinus arrhythmia is usually physiologically caused by respiration (= respiratory sinus arrhythmia).