Pulmonary vascular resistance in ventricular septal defects: The long-term prognosis as evaluated by the thermodilution method

Abstract

Twenty-six children with ventricular septal defects were investigated using the thermodilution method for determining pulmonary blood flow and calculating pulmonary vascular resistance (PVR). Fourteen were followed sequentially. All were below 2 years of age at the first investigation. Eleven of them had a PVR of three units or more. Six of the children in this group died; four at operation, two before operation. One has a residual shunt and equilibrated pressures. Fifteen patients had a PVR below three units; two of them died, none had any long-term complications. In the high-resistance group, sequential determinations of PVR with the thermodilution method further helped to separate those with a poor prognosis from those whose pulmonary vascular bed was still reactive and for whom prognosis was good.

Key Words:

• cardiac output
• heart defects ventricular septum
• pulmonary circulation