EFFECT OF INCREASES AND DECREASES IN BREATHING RATE ON HEART RATE AND FINGER PULSE VOLUME

ABSTRACT Twenty per cent changes in breathing rate (increases and decreases), sustained for 10 min, do not change average heart rate; however, increases in breathing rate tend to decrease the standard deviation of heart rate and decreases in breathing rate tend to increase the standard deviation of heart rate. Neither increases nor decreases in breathing rate abolish sinus arrhythmia. Finger pulse volume is decreased by both increases and decreases in breathing rate. The standard deviation of finger pulse volume is decreased during slow‐paced breathing and unchanged during fast‐paced breathing. The decrease in finger pulse volume occurs within the first minute during slow‐paced breathing; however, during fast‐paced breathing the decrease does not occur until about 4 min after the onset of paced breathing.