Characterization of left ventricle vortex ring decay in the growing heart

During early diastolic filling, the left ventricle (LV) relaxes, creating a pressure imbalance which drives blood flow from left atrium (LA) into the LV. The incoming flow pushes open the mitral valve (MV) and rolls-off the MV leaflets to create a vortex ring (VR). Characteristics of the VR, its formation, and decay, provide essential information on LV diastolic filling. Interaction of the VR with the LV walls and viscous losses causes energy loss and decay. Previous research suggests that decay grows with increasing confinement ratio between the VR diameter and LV diameter (D_LV /D_MV). However, prior studies have not considered how VR decay varies with age-related LV growth, critical for understanding early heart development and potentially aiding clinically diagnosing heart failure. We quantified VR decay rate and other related vortex properties across six age groups: newborn (0-2 months old m/o; n=8), infant (3-11 m/o; n=6), toddler (1–4 years old y/o; n=5), child (5-10 y/o; n=5), adolescent (11-18 y/o; n=8), and young adulthood (19-40 y/o; n=13). We will analyze how VR decay scales across varying age, testing whether age-related growth of the heart requires an increase in VR decay rate as LV confinement remains near constant.