This prospective observational study aims to evaluate the correlation between cardiac index measured by the MostCare™ system (Pressure Recording Analytical Method, PRAM) and cerebral/renal regional oxygen saturation measured by near-infrared spectroscopy (NIRS) and arterial lactate levels in neonates and infants (body weight 2.5-3.5 kg, age 0-3 months) undergoing surgical repair of aortic coarctation. Measurements will be recorded at four intraoperative time points: after anesthesia induction, before aortic cross-clamp, 3 minutes after cross-clamp release, and at end of surgery. No additional intervention beyond standard anesthesia and surgical care will be applied.