Case of RV hypertrophy and biventricular dysfunction

Case by Gabriel Altit

December 23rd, 2023

The mother was 38-week pregnant with no prenatal care, obesity and untreated diabetes mellitus during most of the pregnancy. The mother presented late during pregnancy to care and was managed with insulin. Late pregnancy ultrasound revealed polyhydramnios and macrosomia. An elective c-section was planned. Birth Weight: 4,585 grams. APGAR Scores: 1, 6, 8. The baby was born flat with a heart rate (HR) < 100 bpm. Positive pressure ventilation (PPV) was initiated. Respiratory distress was noticed with grunting requiring continuous positive airway pressure (CPAP) with FiO2 at 50-100%. Cord pH was recorded as arterial: 7.05. Due to significant respiratory distress and hypoxia, intubation was performed. Blood gas pre-intubation was: pH of 6.84, CO2 of 122, and base excess of -17 at 2 hours after birth. On arrival to our tertiary centre, the patient had moderate hypoxic-ischemic encephalopathy (HIE), a discontinuous depressed voltages aEEG and ongoing respiratory distress.  The baby received surfactant with improvement in peak inspiratory pressure and FiO2 (70% to 30-40%). The patient showcased some differential of saturation and iNO was initiated at 20 ppm with good response. A TNE was performed on iNO. It showcased RV hypertrophy, a bidirectional PDA and a decreased biventricular function. Dobutamine was initiated at 5 mcg/kg/min intravenous and a repeat echocardiography was performed in the afternoon. The systolic RV function normalized but the PPHN was still present (bidirectional PDA, bidirectional PFO and RV-RA gradient by tricuspid regurgitant jet of 80 mmHg with similar systemic systolic blood pressure at that time). Considering the patient had adequate systolic systemic BP and adequate urine output, the patient was initiated on low dose milrinone (0.3 mcg/kg/min). The following day, the TNE outlined normalization of the RV and LV function, with a PDA mostly left to right (trivial duration of right to left). The Dobutamine was weaned. The iNO was weaned after rewaring, followed by progressive weaning of milrinone over 24 hours.