Shear Stress, Energy Losses, and Costs: A Resolved Dilemma of Pulsatile Cardiac Assist Devices

Table 1

Pulsatile and nonpulsatile (NP) flows pressures records (mmHg) of three different mock circuits (I, II, and III).

Groups	P1	P2	P3	P4	P5
(1)
NP (I)	32.5±1.3	31.3±1.3	30.3±0.5	30.3±0.5	30.8±0.5
NP (II)	36.3±1.3	37.8±1	39.5±0.6	38.5±0.6	39.3±0.5
NP (III)	40.3±1	42.3±1	43±0.00	42.3±0.6	43±0.00
(2)
Pm. (I)	34.5±1.7	34.5±1.3	33.5±1.7	32.3±1	31.8±1
Pm. (II)	39.3±0.5	40±0.8	40.8±0.6	40.5±0.6	40.3±0.5
Pm. (III)	43±1.2	46±2.2	46.3±1.5	44±0.8	44.8±0.5
(3)
Ps. (I)	72±3.5	81±11	92.8±4.9	98±11.5	92.8±5.6
Ps. (II)	97.3±7	92.3±6	90±11.2	81.3±7.5	82.3±8.4
Ps. (III)	84.3±6.6	79.8±5.9	79.8±5.5	69±3.9	69±4.2
(4)
Pd. (I)	−4.4±3.2	−6.5±7.4	−13.6±11.7	−35.3±8	−33.5±13.3
Pd. (II)	−1.1±6.2	−7.8±4.4	−0.8±9.4	5.6±8.4	13±3.2
Pd. (III)	0.5±10	5.3±5.3	7.5±7.5	20.3±3.8	20.3±0.5
(5)
PP (I)	76.4±3.4	87.5±11.8	106.4±15.9	133.3±17.7	126.3±18.6
PP (II)	98.3±7.9	100±10.4	100.3±10.3	75.7±15.4	66±6.1
PP (III)	83.8±9.2	74.5±8.7	72.3±12.6	48.8±7.1	48.8±4.7

Circuit I: P1, P2: pre/post-oxygenator pressure; P3, P4: pre/post-tube. Circuit II: P1: pre-oxygenator; P2, P3: pre/post-tube; P4: pre-aortic cannula. Circuit III: P1, P2: pre/post-tube; P3: post-oxygenator; P4: pre-aortic cannula. P5: post simulated resistance in all circuits. Pm: mean pulsatile pressure; Ps: systolic pulsatile pressure, Pd: pulsatile diastolic pressure; PP: pulse pressure. Pulse pressure was higher at P5 in circuit I, compared with II and III. Pm was higher at P5 compared to NP with position I. (𝑃<0.001).