Influence of the body position on the systolic speckle-tracking derived left and right ventricular function indexes of ultra-trailers

Abstract

Preload is prone to vary during ultra long duration exercise (ULDE) and this can complicate the analysis of left ventricular (LV) and right ventricular (RV) function under such conditions. We studied LV and RV contractility indexes while preload conditions were changed. Twenty-two healthy male amateur ultra trailers (mean age 47) underwent serial echocardiographic assessments in three positions at rest: left-side decubitus in the standard position (P1), head-up and legs down (P2) then in the Trendelenburg position (P3). Heart rate (HR) and systolic blood pressure (SBP) were monitored. Preload was estimated by the biplane LV end diastolic volume (LV-EDV). Statistical analyses were conducted using repeated measures ANOVA. HR and SBP did not vary. LV-EDV was significantly greater in P3 than in P2 ( P = 0.004) and in P1 ( P = 0.001). LV Radial Peak Strain (LV-RPS) and LV Circumferential Peak Strain (LV-CPS) did not change. LV Longitudinal Peak Strain (LV-LPS) was greater in P3 than in P2 ( P < 0.01) and greater in P1 than in P2 ( P < 0.001). RV Longitudinal Peak Srain (RV-LPS) was greater in P3 than in P2 ( P < 0.03). The LV Longitudinal Strain Rate (LV-LSR), the LV Circumferential Strain Rate (LV-CSR) and the RV Longitudinal Strain Rate (RV-LSR) were not modified by the change of body position ( Table 1 ). LV-LSR, LV-CSR and RV-LSR as well as LV-RPS and LV-CPS were not influenced by the body position. These latter ventricular indexes seem to be less preload dependent than LV-LPS and RV-LPS and may be favored when assessing LV and RV function during ULDE.