Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Organ Perfusion

Background:

• Acute myocardial infarction (AMI) can lead to biventricular heart failure.
• Mechanical circulatory support is crucial for managing severe heart failure.
• Understanding the impact of pulsatile versus non-pulsatile flow on organ perfusion is vital.

Purpose of the Study:

• To compare the effects of pulsatile and non-pulsatile biventricular assist circulation on major organ function in a porcine model of AMI.
• To evaluate the impact on regional blood flow in the kidney, brain, and liver, as well as metabolic markers.

Main Methods:

• A 3-hour biventricular assist circulation was established in pigs post-AMI.
• Pulsatile and non-pulsatile pumps were used for left ventricular support.
• Right ventricular support utilized a non-pulsatile pump.
• Regional blood flows (kidney cortex/medulla, brain white/gray matter, liver), arterial flows, arterial ketone body ratio (AKBR), and lactate/pyruvic acid (L/P) ratio were measured.

Main Results:

• Pulsatile assist improved renal cortical blood flow and intrarenal redistribution, while non-pulsatile assist decreased both.
• Significant differences in liver regional blood flow, AKBR, and L/P ratio were observed between pulsatile and non-pulsatile groups.
• No significant differences in brain white/gray matter blood flow or carotid arterial flow were found between the groups.

Conclusions:

• Pulsatile biventricular assist circulation demonstrates superior perfusion in the kidney and liver compared to non-pulsatile support.
• Pulsatile flow enhances microcirculation at the cellular level in the early treatment of acute heart failure.
• These findings suggest pulsatile assist may offer better organ protection in acute cardiac events.