Respiratory sinus arrhythmia and pulmonary gas exchange efficiency: time for a reappraisal

Respiratory sinus arrhythmia is associated with efficiency of pulmonary gas exchange in healthy humans.

Respiratory sinus arrhythmia (RSA) may be associated with improved efficiency of pulmonary gas exchange by matching ventilation to perfusion within each respiratory cycle. Respiration rate, tidal volume, minute ventilation (.VE), exhaled carbon dioxide (.VCO(2)), oxygen consumption (.VO(2)), and heart rate were measured in 10 healthy human volunteers during paced breathing to test the hypothesi...

Diminishment of Respiratory Sinus Arrhythmia

Background. The development of a microcomputer-based device permits quick, simple, and noninvasive quantification of the respiratory sinus arrhythmia (RSA) during quiet breathing. Methods and Results. We prospectively and serially measured the radionuclide left ventricular ejection fraction and the RSA amplitude in 34 cancer patients receiving up to nine monthly bolus treatments with doxorubici...

Update on Respiratory Physiology: Pulmonary Gas Exchange

Does respiratory sinus arrhythmia occur in fishes?

The hypothesis that respiratory modulation of heart rate variability (HRV) or respiratory sinus arrhythmia (RSA) is restricted to mammals was tested on four Antarctic and four sub-Antarctic species of fish, that shared close genotypic or ecotypic similarities but, due to their different environmental temperatures, faced vastly different selection pressures related to oxygen supply. The intrinsi...

Fractal ventilation enhances respiratory sinus arrhythmia

BACKGROUND Programming a mechanical ventilator with a biologically variable or fractal breathing pattern (an example of 1/f noise) improves gas exchange and respiratory mechanics. Here we show that fractal ventilation increases respiratory sinus arrhythmia (RSA) -- a mechanism known to improve ventilation/perfusion matching. METHODS Pigs were anaesthetised with propofol/ketamine, paralysed wi...