PULMONARY ATRESIA WITH INTACT VENTRICULAR SEPTUM: NOT CLEARED FOR TAKEOFF

Abstract

TOPIC: Pulmonary Vascular Disease TYPE: Fellow Case Reports INTRODUCTION: In patients with underlying lung disease, pulmonary evaluation is required prior to air travel due to hypoxic conditions in higher altitudes. We present a case of a young man aspiring to become a pilot, found to have a congenital cardiopulmonary defect of pulmonary atresia. CASE PRESENTATION: An 18 year old male with right pulmonary atresia and intact ventricular septum (PA-IVS) presented to the pulmonary clinic seeking medical clearance for flight training school, endorsing fatigue and dyspnea on exertion. Vitals signs and physical examination were benign without cardiac murmurs, peripheral edema, or cyanosis. Chest CT revealed absent right PA (pulmonary artery) with contrast reflux. A subsequent angiogram revealed blood flow from the right internal mammary artery to the right upper PA and from the celiac and inferior diaphragmatic artery to the right lower PA. Left and right cardiac catheterization showed normal pressures in the right atrium, right ventricle, and PA. Mean PA pressure was 14 mmHg, and wedge pressure was 6 mmHg. Left ventricular end diastolic pressure was 6 mmHg, with normal coronary artery and vein anatomy. Oxygen saturations were: SVC 86%, RA 82%, RV 81%, left PA 81%, and femoral artery 96%. Treadmill stress test was inconclusive due to early termination as the patient did not achieve 85% of maximum heart rate. Occupational medicine recommended HAST (high altitude simulation testing) in concordance with FAA regulations. Before HAST was performed, the patient opted out of his dream career of becoming a pilot. DISCUSSION: PA-IVS is a rare congenital heart disease accounting for < 1 % of total heart defects [2]. It is characterized by atresia of the RV outflow tract. The precise cause is unclear, but thought to be related to an insult during embryological development. PA-IVS can be classified into membranous and muscular forms with the former harboring a better long term prognosis. The muscular form is associated with abnormal connections between the RV and coronary artery. In our patient, left heart catheterization did not reveal abnormal coronary anatomy to suggest muscular PA-IVS.HAST is utilized in patients with cardiopulmonary defects to predict physiological response to hypobaric conditions at higher altitudes. The patient is asked to breathe a mixture of gases with an oxygen saturation of 15.1%, and simulates cabin pressures up to 2400 meters. The test is considered abnormal if there is evidence of hypoxemia (pAO2 < 50 mmHg), symptoms, and/or arrhythmias. We believe that our patient would have had an appropriate response to HAST due to a favorable form of PA-IVS and normal cardiopulmonary pressures and saturations. CONCLUSIONS: In adolescents with congenital cardiopulmonary defects a thorough workup including HAST is recommended prior to allowing exposure to a suboptimal environment. REFERENCE #1: Daubeney PE, Sharland GH, Keeton BR, et al. Pulmonary atresia with intact ventricular septum. Circulation 1998 (8(6): 562-566. REFERENCE #2: Ferencz C, Rubin JD, McCarter RJ, Brenner JI, Neill CA, Perry LW, Hepner SI, Downing JW. Congenital heart disease: prevalence at livebirth. The Baltimore-Washington Infant Study. Am J Epidemiol. 1985 Jan;121(1):31-6. DISCLOSURES: No relevant relationships by Moises Cossio, source=Web Response No relevant relationships by Domingo Franco-Palacios, source=Web Response No relevant relationships by Arjun Mahendra, source=Web Response No relevant relationships by Toribiong Uchel, source=Web Response