Question: Mr. Lopez, a 65-year-old man, presents to the clinic with complaints of frequent dizziness and fatigue, especially when standing up quickly. His blood pressure is recorded at 90/60 mmHg, and his heart rate is 110 bpm. Upon further examination, it is found that his cardiac output is low, and systemic vascular resistance is also reduced. These findings suggest that his body is not maintaining adequate perfusion pressure, leading to symptoms of lightheadedness and fatigue. The physician explains that cardiac output (CO), which is the product of heart rate (HR) and stroke volume (SV), and vascular resistance together determine blood pressure (BP). In Mr. Lopez's case, both CO and resistance are low, resulting in hypotension and poor tissue perfusion. Physiological Factor Effect on Perfusion Decreased cardiac output [ Select ] Decreased vascular resistance [ Select ] Decreased blood pressure. Need Assignment Help?