Longitudinal contractile reserve - VO2relationship
The augmentation of longitudinal velocity showed a strong correlation with VO2 throughout exercise for the septal S’ (rho= 0.86, p<0.0001), the lateral S’ (rho=0.78, p<0.0001) and for the average S’ (rho=0.83, p<0.0001) throughout exercise (Figure 2). Diastolic velocities also demonstrated a good relationship with VO2 (septal E’; rho=0.8, p<0.0001; lateral E’; rho=0.78) (Table 2). The relationship was stronger with the septum than the lateral wall (Table 3).
On multivariate testing only stroke volume and systolic velocities (especially at RER> 1 in the septum) were predictive of VO2peak. Diastolic parameters, ejection fraction as well as both global longitudinal and circumferential strain showed no correlation with VO2peak (Table 4).