This observational ambispective cohort study aims to establish reference values for cardiac structure and function, coronary artery dimensions, and carotid intima-media thickness (cIMT) in a healthy pediatric population living in Italy. Healthy children aged 0-18 years undergoing cardiologic evaluation will be enrolled. Echocardiographic and carotid ultrasound parameters will be collected together with anthropometric and demographic data. The study includes both retrospective and prospective cohorts.