Effects of diltiazem on sympathetic activity in patients with aneurysmal subarachnoid hemorrhage

This study evaluated the effect of diltiazem, a calcium antagonist, on sympathetic activity in patients with aneurysmal subarachnoid hemorrhage (SAH) during the hyperacute stage. Of patients with aneurysmal SAH who underwent aneurysm repair between August 2008 and June 2011, 119 consecutive patients were enrolled in this prospective study. On admission, patients were assigned to an antihypertensive treatment receiving continuous infusion of diltiazem (67 patients) or nicardipine (52 patients). Plasma levels of adrenaline (AD), noradrenaline (NA), and dopamine (DP) were repeatedly measured using high-performance liquid chromatography (HPLC). There were no significant differences in patient characteristics or aneurysm topography between the two groups. In all patients, acute surge of catecholamines was observed with mutual correlation. However, patients receiving diltiazem exhibited a significantly lower plasma concentration of DP than those receiving nicardipine, 3 and 6 h after admission. A similar trend was observed for NA, but the difference was not significant at 6 h. Conversely, the concentration of AD was similar between the two groups. Diltiazem may suppress sympathetic activity in the hyperacute stage of aneurysmal SAH. Further studies are needed to verify the beneficial effect of diltiazem in patients with SAH.