This patient most likely has orthostatic hypotension. Orthostatic hypotension, sometimes called postural hypotension, is a medical condition when the patient’s blood pressure drops after sudden changing to standing position from a sitting or lying position. During orthostatic hypotension the blood pressure is low and the pulse is high. The best next step is to assess the patient's pulse and blood pressure to confirm the diagnosis. Calling the doctor will be an appropriate next step after assessing the blood pressure and pulse. Defibrillation would be an appropriate procedure for patients with ventricular fibrillation on the cardiac monitor. Cardiopulmonary resuscitation would be an appropriate next step if the patient has no pulse.