Pulmonary arterial hypertension after repair of tetralogy of Fallot

Abstract

Sixty-one of approximately 1,400 patients who underwent complete repair of tetralogy of Fallot had pulmonary arterial hypertension (PAH) after repair; i.e., pulmonary artery pressure (PAP) > 50 mm. Hg or PAP/LV > 0.5. Analysis of this experience showed that the prognostic significance of an increased PAP depends on its etiology, severity, and degree of associated residual pulmonary stenosis. Findings of a residual ventricular septal defect, a pulmonary-systemic arteriolar resistance ratio (Rpa/Rs) > 0.6 or Rpa > 12 units square meter, or a ratio of right to left ventricular (RV/LV) peak systolic pressure > 0.7 were particularly adverse signs, whereas peripheral pulmonary arterial obstructions (MPPAO) or lower levels of pulmonary arteriolar resistance were generally well tolerated. Pulmonary regurgitation was of little prognostic significance despite the PAH. Late functional results were good, but these did not correlate closely with late hemodynamic findings. Of interest was the development of pulmonary stenosis in 4 of the 10 patients with MPPAO who were restudied. Improved results can be achieved in this group by detecting before operation, and excluding from operation, patients who have excessive pulmonary vascular resistance (predominantly patients with Potts anastomosis) and by intraoperative monitoring of PAP routinely after repair; if PAH is present, a possible residual ventricular septal defect must be sought and, if found, closed at that time.