Co₂ and coronary flow regulation

Summary

These data indicate that the observed$P_{CO_2 }$ change following an abrupt change in myocardial O₂ consumption, occurs too slowly to participate in the initial adjustment in metabolic coronary flow change, which is essentially complete within 30 sec. Also, the magnitude of$P_{CO_2 }$ response is insufficient to conclude that CO₂ can provide the major cause of flow regulation. However, CO₂ could act as a back-up regulator. These conclusions may be modified if further information becomes available.