Texas Center for Pediatric and Congenital Heart Disease, Dell Medical School, University of Texas at Austin Austin, Texas, United States
Abstract:
Introduction: There is evidence suggesting an association between pulmonary arterial hypertension (PAH) and nutritional deficiencies. We describe a child with a behavioral restrictive diet who developed PAH associated with vitamin C deficiency.
Case Description: The patient is a 5-year-old boy with autism spectrum disorder who presented with 4 weeks of unexplained refusal to walk, progressive pallor, and palpitations. Three months prior, he suffered a fall with bilateral knee swelling and bruising. Over the last month, he developed increased fatigue, sleepiness, lethargy and decreased oral intake.
At the emergency department, his vitals included heart rate of 166 bpm, blood pressure of 122/93 mmHg, saturating 97% in room air. He appeared pallid and tired. Laboratory studies showed elevated inflammatory markers and microcytic anemia. An ECG demonstrated sinus tachycardia and right ventricular hypertrophy and a chest X-ray showed airspace opacification of the left hilar region. Labs revealed elevated troponin-I at 0.09 ng/mL, BNP at 998 pg/dL, D-dimer at 1635 ng/mL and negative COVID-19 PCR. A standard, contrast-enhanced CT scan showed moderate to severe dilation of the right atrium and right ventricle and dilation of main and branch pulmonary arteries. Echocardiogram showed right ventricle dilation and a tricuspid regurgitant velocity of 4.3 m/sec. Due to concerns for pulmonary embolism, he was initiated on heparin infusion and transferred to our center.
On arrival, he received a blood transfusion and continued on anticoagulation. A CT angiography showed no evidence of pulmonary embolism and femoral doppler ultrasound did not suggest deep venous thrombosis. A cardiac catheterization demonstrated baseline pulmonary arterial pressure of 34 mmHg and pulmonary vascular resistance of 7.73 woods units*m², 30 mmHg and 5 woods units*m² on 100% oxygen and 17 mmHg and 2.59 woods units*m² on nitric oxide, respectively. Additionally, an angiogram showed no embolus (Figure).
He was started on sildenafil and inhaled nitric oxide on hospital day 6. New symptoms developed including petechial rash, hematuria, and pain on lower extremities. Further history revealed an underlying behavioral restrictive diet. Empiric ascorbic acid supplementation and amlodipine were started. Serum vitamin C levels measured < 5 umol/L. With treatment, he had declining BNP levels, echocardiogram improvement of right ventricular function and was discharged on amlodipine, sildenafil, and ascorbic acid after hospital day 15. At follow up visit he showed improvement in his PAH and improved overall mobility.
Discussion: PAH can be an unusual presentation of scurvy and misdiagnosed as a pulmonary embolism. This case highlights the importance of having Vitamin C deficiency as a differential diagnosis for unexplained PAH, especially in patients at risk for malnutrition, such as those with selective eating patterns as seen in autism.
