The first step in emergency medical treatment of a hypercyanotic spell includes comforting the patient in order to allay anxiety and administration of oxygen by mask. Oxygen is a pulmonary vasodilator and also will increase systemic oxygen content, although not significantly until pulmonary blood flow is increased. An intravenous line must be placed as expeditiously as possible and a fluid bolus given rapidly, in order to increse right ventricular filling volume. Sytemic arteriolar vasoconstriction by an agent such as norepinephrine enhances pulmonary blood flow by raising systemic resistance. Beta blockers act directly by relaxing the musculature of the right ventricular outflow tract, thereby decreasing the obstruction. Calcium channel blocking agents, on the other hand, dilate the systemic arterial bed, decreasing systemic vascular resistance. This will exacerbate the problem and is contraindicated.