The effects of stimulation of the left atrial receptors in the cat

In the cat, distension of the left atrial appendages by means of small balloons resulted in variable changes in the heart rate. Distension of the junctions between the upper two left pulmonary veins and the left atrium resulted in a small but statistically significant increase in the heart rate. Distension did not result in any significant changes in the blood pressure. The increases in heart rate are far less than observed in the dog and it is suggested that the atrial receptors might play a less important role in cardiovascular control in the cat than they do in the dog.