Relationship between the Ventilation-Carbon Dioxide Production Slope during Cardiopulmonary Exercise Testing and Left Ventricular Function in Patients with Acute Myocardial Infarction

Abstract

The relation between VE-VCO₂ slope and left ventricular function was examined in 38 patients (37 male and 1 female; mean age 55.1 ± 7.3 years) with acute myocardial infarction (AMI). Left ventricular function was measured with electrocardiogram gated single photon emission computed tomography in the acute phase (4.0 ± 2.4 days after onset) and the chronic phase (170.7 ± 57.4 days after onset). Cardiopulmonary exercise testing (CPX) was performed 33.9 ± 13.5 days after the onset of AMI for expiration gas analysis. In the chronic phase, the VE-VCO₂ slope showed significant correlation with the end-diastolic volume (r=0.52; p<0.001), end-systolic volume (r=0.46; p<0.004) and ejection fraction (r=-0.34; p<0.03). Therefore, the left ventricular function in the chronic phase could be estimated by the VE-VCO₂ slope. The VE-VCO₂ slope of the remodeling (RM) group was significantly higher than that of the non-RM group (p<0.02). There was no significant difference between the Peak VO₂ values of the two groups. Thus, the VE-VCO₂ slope can be used to estimate the left ventricular function and to predict RM.