Cardiac output varies under different physiological conditions. It is decreased by?: (A) Increased hea rate, (B) Decreased hea rate, (C) Increased stroke volume, (D) None of the above
Answer is B. Cardiac output is the product of the hea rate and stroke volume (CO = HR x SV). Therefore, cardiac output decreases by bradycardia. Ref: Mohrman D.E., Heller L.J. (2010). Chapter 3. The Hea Pump. In D.E. Mohrman, L.J. Heller (Eds), Cardiovascular Physiology, 7e.