We present the case of a 3-month-old boy with pulmonary arterial hypertension after corrective repair of total anomalous pulmonary venous connection. The patient developed severe pulmonary arterial hypertension with a high mean pulmonary arterial pressure of 45 mmHg. We performed continuous monitoring of pulmonary arterial pressure using a tip deflecting microcatheter in the intensive care unit. We successfully managed this patient based on real-time pulmonary arterial pressure measurements. Continuous real-time monitoring of pulmonary arterial pressure using this microcatheter enables individualized targeted therapy for infants with pulmonary arterial hypertension.