Sub-arachnoid haemorrhage (SAH) are often due to ruptured intracerebral aneurysms and are associated with an importante morbi-mortality. SAH are often complicated by delayed cerebral ischemia (DCI) potentially due to cerebral vasospasm (CVS). A recent study showed that levosimendan, an inotropic and vasodilatory drug, could reduce the incidence of CVS and potentially improve patient outcome. In this pilot randomized controlled trial, we will evaluate the impact Levosimendan vs Placebo in SAH patient on the occurrence of CVS and DCI. Study population: adult patient admitted to ICU for aneurysmal SAH WFNS grade I-IV and mFisher 3-4. Intervention: Levosimendan (0.1 µg/kg/min) or placebo infusion at Day 1 and 8. Primary outcome: incidence of DCI or CVS at day 14 Duration of the study: 24 months Number of patients: 30 (15 patients per group) Number of center: 1