Introduction: Exercise conditions have considerable influence on the hemodynamics. Yet, the studies on the effects of the exercise conditions on the blood flow patterns and associated shear stresses are scarce.
Aim: Investigation of blood flow patterns within the right ventricle (RV) and assessment of the relation between the heart rate and hydrodynamic stresses.
Methods: Three-Dimensional Particle Tracking Velocimetry (3D-PTV), an optical measurement technique, has been utilized to assess the phase averaged and fluctuating flow velocities in an anatomically accurate silicone phantom of the human right heart reconstructed from a 3D volume rendering of a high-resolution magnetic resonance (MR) scan. Four different heart rates were studied. The region of interest comprises subtricuspid region, RV outflow tract and RV apex.
Results: Our results show that hemodynamics in the right ventricle is considerably influenced by the heart rate. It is shown that peak mean kinetic energy for the 120bpm case is twice as the one for the 60 bpm case (52.2±0.34J/m3 for 60bpm and 107.9±0.34J/m3 for 120bpm). Moreover, it is found that peak systolic wall shear stress for the 120bpm case (39.48±0.18Pa) is considerably higher than the one for the 60 bpm case (24.2±0.18Pa). Finally, it is shown that high shear stress regions develop in the proximity of the RVOT during systolic phase (Figure 1).
Conclusions: This in vitro study focusing on the influence of heart rate on the right ventricular kinetic energy showed that peak systolic wall shear stress increases at higher heart rates and those high stress regions develop in the vicinity of the RVOT during cardiac systole. Further measurements will be performed to reveal the interplay between the sports type and hemodynamics.