Clinical Usefulness of Response Profiles to Rapidly Incremental Cardiopulmonary Exercise Testing
Figure 8
Exercise-induced right-to-left shunt as suggested by sudden decrease in oxyhemoglobin saturation by pulse oximetry () and abrupt increases in the ventilatory equivalents for CO2 and ( and ) associated with a sustained decrease in the end-tidal partial pressure for CO2 () with a concomitant increase in in a patient with pulmonary arterial hypertension. Shunting of systemic venous blood in the arterial circulation stimulated the peripheral chemoreceptors thereby leading to this pattern of ventilatory and gas exchange responses. Unl is unloaded pedaling.
