The anesthetic induction and the beginning of mechanical ventilation are the most sensible times due to the risk of hemodynamic decompensation. The suppression of the sympathetic tonus which is consequence of the anesthetic induction, decrease the systemic vascular resistances and lead to decrease of blood pressure. In return, the anesthetic induction is associated with an increase of pulmonary vascular resistances, resulting in increase of the postcharge and the work of the right ventricle (VD). These systemic and pulmonary hemodynamic modifications can lead to equalization, or even an inversion of the systemic and pulmonary pressures. As consequence, a hemodynamic collapse or even a heart arrest can arise.