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In the event of end-stage heart failure, a left ventricular assist device (LVAD) can be used as a heart transplant bridge to keep a patient alive. The first iterations of LVADs were pulsatile and mimicked the physiological pumping action of the heart (Figure 1) .
Figure 1 A pulsatile-flow LVAD schematicA pulsatile-flow LVAD assists ventricular systole by mechanically pumping blood from a weakened left ventricle into the aorta through a pair of one-way valves. The pressure differential ΔP generated by the pump is related to cardiac output (CO) and vascular resistance (VR) :ΔP = CO × VREquation 1The efficiency and performance of the heart (or LVAD) can be determined by the patient's cardiac pressure-volume (PV) loop. A cardiac PV loop plots the pressure and volume of the blood in the left ventricle throughout a single cardiac cycle (Figure 2) .
Figure 2 Cardiac PV Loop of a pulsatile-flow LVADBlood pressure is often represented by only two numbers: arterial systolic and diastolic pressures. A more detailed representation of blood pressures is shown in a blood pressure profile, which graphs the blood pressure throughout the length of the different vessel groups (Figure 3) . Multiple pressure fluctuations are shown within a vessel because the pressure is traced across multiple cardiac cycles.
Figure 3 Blood pressure profile of the different vessels
-The mean arterial pressure (MAP) is used to approximate the average blood pressure of an individual's arteries:MAP = DP + (SP - DP) /3where DP is diastolic pressure and SP is systolic pressure. What is the MAP for the blood pressure profile shown in Figure 3?

Question

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In the event of end-stage heart failure, a left ventricular assist device (LVAD) can be used as a heart transplant bridge to keep a patient alive. The first iterations of LVADs were pulsatile and mimicked the physiological pumping action of the heart (Figure 1) .

Figure 1 A pulsatile-flow LVAD schematicA pulsatile-flow LVAD assists ventricular systole by mechanically pumping blood from a weakened left ventricle into the aorta through a pair of one-way valves. The pressure differential ΔP generated by the pump is related to cardiac output (CO) and vascular resistance (VR) :ΔP = CO × VREquation 1The efficiency and performance of the heart (or LVAD) can be determined by the patient's cardiac pressure-volume (PV) loop. A cardiac PV loop plots the pressure and volume of the blood in the left ventricle throughout a single cardiac cycle (Figure 2) .

Figure 2 Cardiac PV Loop of a pulsatile-flow LVADBlood pressure is often represented by only two numbers: arterial systolic and diastolic pressures. A more detailed representation of blood pressures is shown in a blood pressure profile, which graphs the blood pressure throughout the length of the different vessel groups (Figure 3) . Multiple pressure fluctuations are shown within a vessel because the pressure is traced across multiple cardiac cycles.

Figure 3 Blood pressure profile of the different vessels
-The mean arterial pressure (MAP) is used to approximate the average blood pressure of an individual's arteries:MAP = DP + (SP - DP) /3where DP is diastolic pressure and SP is systolic pressure. What is the MAP for the blood pressure profile shown in Figure 3?

Quizplus · Accepted Answer

11ecba2d_12e6_e907_a3bf_efe7de1eb6e7_MD0008_00 Mean arterial pressure (MAP) is defined as the average arterial blood pressure throughout a cardiac cycle. Due to the oscillatory nature of arterial blood pressure (as seen in the figure above), MAP cannot simply be calculated as the midpoint between systolic and diastolic pressure (Choice D). MAP is approximated from arterial systolic pressure (SP) and diastolic pressure (DP) with the given equation 11ecba2d_12e6_e908_a3bf_bd93e045bc05_MD0008_00 Arterial systolic pressure is the maximum blood pressure in the arteries due to ventricular contraction, and arterial diastolic pressure is the minimum blood pressure in the arteries due to heart relaxation. From Figure 3, the highest arterial pressure is 120 mm Hg, and the lowest arterial pressure is 90 mm Hg. Using 120 mm Hg as SP and 90 mm Hg as DP, 11ecba2d_12e6_e909_a3bf_d559b0474082_MD0008_00 The MAP of the blood pressure profile is 100 mm Hg. (Choice A) The systolic and diastolic measurements for MAP are taken from the arteries. If the lowest blood pressure in the entire circulatory system (0 mm Hg at the veins) is used as the arterial diastolic pressure, MAP will be incorrectly calculated as 40 mm Hg. Educational objective: Systolic pressure is the maximum measured blood pressure due to ventricular contraction, and diastolic pressure is the minimum measured blood pressure due to heart relaxation. The mean arterial pressure (MAP) is approximated from arterial systolic (SP) and diastolic (DP) pressures by 11ecba2d_12e6_e90a_a3bf_4b012c08e98a_MD0008_00 __________

Passage In the Event of End-Stage Heart Failure, a Left Ventricular