[Assessment of left ventricular function by pressure-volume loop in VSD and TOF before and after operation].

Abstract

This study estimates the perioperative left ventricular function of VSD and TOF by using Pressure-Volume (PV) loop. The most characteristic hemodynamic change of VSD is a decreased volume load. Although ejection fraction significantly decreased after the operation, this change did not mean a deteriorated left ventricular contractility. Emax, which is an index of left ventricular contractility on PV loop, improved and pressure-volume area (PVA) which is correlated with 02 consumption of left ventricule was reduced. Mechanical efficiency of left ventricular energetic state did not significantly change. Left ventricular volume and ejection fraction in TOF slightly increased after the operation. Increased ejection fraction reflected a compensation to volume overload after surgery. Emax slightly decreased and PVA increased. Meanwhile mechanical efficiency increased after the operation indicating well preserved ventricular contractility. In particular, the shape of PV loop of both VSD and TOF eventually became usual square after operation due to recover of the isovolumic contraction and relaxation phase. These characteristics had better to be concerned for improvement of surgical techniques as in conotruncal repair, particularly in TOF in the setting of better quality of life with low atrial pressure.