Dyspnea With Minimal Exertion In A Pediatric Patient

HISTORY: A 16-year-old transgender male presented to the emergency department with months of shortness of breath, chest pain, and vomiting. Patient had no significant past medical history. Patient was found to have bilateral submissive pulmonary emboli (PE), with right heart strain and hypertrophy, consistent with long standing PE. Patient was intubated and underwent catheter-directed thrombolysis and anticoagulant therapy. PHYSICAL EXAMINATION: Frail in appearance, Ht: 61.3in; Wt: 107.3 lb; BMI: 20.2 kg/m2; Resting: HR: 71 bpm; BP: 109/64 mmHg; SpO2: 99%; ECG: Sinus bradycardia. DIFFERENTIAL DIAGNOSIS: 1.Pulmonary limitations2.Cardiovascular limitations3.Deconditioning TEST AND RESULTS:Pulmonary function: Normal spirometry and lung volumes, with reduced lung diffusion capacity (DLco: 62% predicted). Constant-load exercise: duration: 3 min; work rate: 49 W (40% of predicted maximum); VO2: 0.64 L/min; normal exercise BP; high HR (186 bpm, 95% of maximum) and lactate (8.1 mmol/L) responses for the low work rate; normal ventilatory reserve (VE/MVV: 59%); increased ventilatory demand (VE/VCO2: 76) and low PETCO2 (18 mmHg) consistent with inefficient gas exchange; no significant desaturation (SpO2: 96%). Cardiac catheterization: Increased mPAP (55 mmHg) and PVR (13.8WU) with normal PCWP (12 mmHg) consistent with pre-capillary pulmonary hypertension. Pulmonary angiography: Abnormal perfusion in both lungs; right lung: partial occlusions in upper lobe and clot in the lower lobe, appearing diseased; left lung: web lesion in the upper lobe vessels and diffusely diseased lingula vessels. FINAL/WORKING DIAGNOSIS: Chronic thromboembolic pulmonary hypertension (CTEPH) TREATMENT AND OUTCOMES: 1.Pulmonary endarterectomy for CTEPH. 2.Lifelong anticoagulation therapy. 3.Patient returned to the laboratory for cardiopulmonary exercise testing four months after pulmonary endarterectomy. Compared with the first exercise test, the patient exercised for a longer duration (6 min) at the same work rate (49 W) and had lower HR response (153 bpm, 78% of maximum), suggesting a slight improvement in exercise tolerance. Ventilatory demand was lower (VE/VCO2: 58) and PETCO2 was higher (24 mmHg), consistent with an improvement in gas exchange. Patient noticed an improvement in functional capacity and is doing better. Supported by: R01HL153963, K99HL164957, King Charitable Foundation, Atwell Gift for Pulmonary Research, Cain Foundation, and Texas Health Presbyterian Hospital Dallas