Interactive worksheet
PETCO2 at AT Index Calculator
PETCO₂ at AT Index: Explanation and Clinical Context The PETCO₂ at Anaerobic Threshold (AT) Index measures the partial pressure of end-tidal CO₂ at the anaerobic threshold during cardiopulmonary exercise testing (CPET). This index reflects ventilatory efficiency and the balance between CO₂ production and elimination. Lower PETCO₂ at AT (<30 mmHg) indicates inefficient ventilation, often observed in patients with hear