Cyanotic congenital heart disease and pregnancy: natural selection, pulmonary hypertension, and anesthesia.

Pregnancy carries substantial maternal and fetal risks in patients with uncorrected or palliatively corrected cyanotic congenital heart disease (CHD). In tricuspid valve Ebstein's anomaly, pregnancy is well tolerated. Maternal mortality in tetralogy of Fallot seems to be less than 10%, but it exceeds 50% in Eisenmenger's syndrome and primary pulmonary hypertension (PPH). Maternal hematocrit greater than 60%, arterial oxygen saturation lower than 80%, right ventricular hypertension, and syncopal episodes are poor prognostic signs. Maternal risk could be reduced by vaginal delivery. Continuous monitoring of arterial and central venous pressure, electrocardiography, and pulse oximetry are recommended for every anesthetic procedure. The use of a pulmonary artery catheter is controversial and probably should be avoided in parturients with cyanotic CHD or PPH. The choice of anesthetic technique and drugs per se is of secondary importance and should be governed by individual preferences. Titration of anesthetic drugs, general anesthesia with controlled ventilation, or, preferably, regional anesthesia with spontaneous breathing should be used cautiously to avoid worsening of the preexisting condition. Prevention of excessive erythrocytosis, volume and blood loss substitution, cardiocirculatory pharmacologic support, prophylaxis of infective endocarditis, and judicious use of anticoagulant drugs should be applied as indicated by the type and presentation of CHD. Poor outcome of pregnancy in PPH requires an early consideration of heart-lung or lung transplantation. Multidisciplinary team effort and prolonged monitoring in the intensive care unit are mandatory to ensure a favorable outcome for cyanotic CHD and PPH parturients.