Inhaled nitric oxide (NO) has been used in the preoperative evaluation of patients with congenital heart disease and pulmonary hypertension. The purpose of this study was to characterize responses in pulmonary vascular resistance (PVR) to oxygen and increasing doses of NO during cardiac catheterization and to determine if any related factors affect the response of the pulmonary vascular bed to NO. A prospective analysis of 42 patients (median age, 3.0 years) with congenital heart disease and pulmonary hypertension who underwent NO testing was performed. Systemic vascular resistance (SVR) and PVR were assessed in room air, 100% oxygen, and oxygen plus 20, 40, and 80 parts per million (ppm) NO. Changes in pulmonary artery pressure, PVR, and SVR were assessed. The response to NO was then correlated to individual patient's age, gender, type of heart defect, the presence of trisomy 21, and baseline PVR/SVR. There was a greater decrease in PVR and PVR/SVR with 20 ppm NO than with oxygen alone. There was no additional decrease at 40 or 80 ppm NO. There was no correlation between age, gender, type of congenital heart disease, and baseline PVR/SVR ratio with the degree of response to NO. Patients with trisomy 21 had less of a response to NO (p = 0.017) than patients without trisomy 21. There is no difference in determining PVR response with doses of NO beyond 20 ppm during cardiac catheterization. Age, gender, and baseline PVR/SVR ratio are not associated with responsiveness to NO. Patients with trisomy 21 may be less responsive to NO.
Folate antagonist are chemotherapeutic agents used in many neoplastic, autoimmune, and inflammatory disorders. The first suggestions that folic acid antagonists were teratogenic in humans were based on reports of failed terminations in mothers given aminopterin in the first trimester. Newborns who survived after aminopterin exposure were noted for years to have defects of the neural tube, skull, or limbs. There is now a well-defined syndrome of congenital anomalies associated with the use of aminopterin. The aminopterin syndrome consists of cranial dysostosis, hypertelorism, anomalies of the external ears, micrognathia, limb anomalies, and cleft palate. The use of aminopterin has now fallen out of favor. Methotrexate is a folate antagonist that is now used more frequently. A similar pattern of malformations has been found in fetuses exposed to methotrexate. If used during pregnancy, it can cause congenital malformations or fetal death. A consistent association between methotrexate exposure and cardiac, renal, or gastrointestinal malformations has not been reported. We report two patients who presented with classic features of aminopterin syndrome combined with significant congenital cardiac malformations after first-trimester in utero methotrexate exposure. Both of these patients survived to undergo corrective cardiac surgery.
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