Abnormal End-Tidal PO2 and PCO2 at the Anaerobic Threshold Correlate Well With Impaired Exercise Gas Exchange in Patients With Left Ventricular Dysfunction

作者：Kano Hiroto; Koike Akira^*; Hoshimoto Iwamoto Masayo; Nagayama Osamu; Sakurada Koji; Suzuki Takeya; Tsuneoka Hidekazu; Sawada Hitoshi; Aizawa Tadanori; Wasserman Karlman

来源：Circulation Journal, 2012, 76(1): 79-87.

DOI：10.1253/circj.CJ-11-0599

• Anaerobic threshold
• End-tidal CO2 pressure
• End-tidal O-2 pressure
• Exercise testing
• (V)over dot O-2

Background: The aim of the present study was to compare the end-tidal O-2 pressure (PETO2) to end-tidal CO2 pressure (PETCO2) in cardiac patients during rest and during 2 states of exercise: at anaerobic threshold (AT) and at peak. The purpose was to see which metabolic state, PETO2 or PETCO2, best correlated with exercise limitation. Methods and Results: Thirty-eight patients with left ventricular (LV) ejection fraction %26lt;40% underwent cardiopulmonary exercise testing (CPX). PETO2 and PETCO2 were measured during CPX, along with peak O-2 uptake (%26lt;(V)over dot%26gt;O-2), AT, slope of the increase in ventilation (%26lt;(V)over dot%26gt;E) relative to the increase in CO2 output (%26lt;(V)over dot%26gt;CO2) (%26lt;(V)over dot%26gt;E vs. %26lt;(V)over dot%26gt;CO2 slope), and the ratio of the increase in %26lt;(V)over dot%26gt;O-2 to the increase in work rate (Delta%26lt;(V)over dot%26gt;O-2/Delta WR). Both PETO2 and PETCO2 measured at AT were best correlated with peak%26lt;(V)over dot%26gt;O-2, AT, Delta%26lt;(V)over dot%26gt;O-2/Delta WR and VE vs. VCO2 slope. PETO2 at AT correlated with reduced peak %26lt;(V)over dot%26gt;O-2 (r=-0.60), reduced AT (r=-0.52), reduced Delta%26lt;(V)over dot%26gt;O-2/1.WR (r=-0.55) and increased %26lt;(V)over dot%26gt;E vs. %26lt;(V)over dot%26gt;CO2 slope (r=0.74). PETCO2 at AT correlated with reduced peak %26lt;(V)over dot%26gt;O-2 (r=0.67), reduced AT (r=0.61), reduced Delta%26lt;(V)over dot%26gt;O-2/Delta WR (r=0.58) and increased %26lt;(V)over dot%26gt;E vs. %26lt;(V)over dot%26gt;CO2 slope (r=-0.80). Conclusions: PETCO2 and PETO2 at AT correlated with peak %26lt;(V)over dot%26gt;O-2, AT and Delta%26lt;(V)over dot%26gt;O-2/Delta WR, but best correlated with increased %26lt;(V)over dot%26gt;E vs. %26lt;(V)over dot%26gt;CO2 slope. PETO2 and PETCO2 at AT can be used as a prime index of impaired cardiopulmonary function during exercise in patients with LV failure. (Circ J 2012; 76: 79-87)

• 出版日期2012-1