Stress hormones cause an increase in blood pressure. I assume this directional effect of stress hormones on blood pressure is adaptive. Vasodilation makes the heart's job easier by increasing the amount of room blood can move through on its way from the heart, decreasing vascular resistance. This of course lowers blood pressure as it spreads out the impact of blood against the arterial walls. So, would the heart work harder to get blood pressure up to the same level it would be if the cardiovascular system were not under the effect of a vasodilator?