Load-independent analysis of a pulsatile right ventricular assist device

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Cardiac Physiology

Background:

• Right ventricular assist devices (RVADs) are crucial for heart transplantation and post-cardiopulmonary bypass support.
• Interest in pulsatile RVADs is growing, but their impact on biventricular function requires load-independent analysis.
• This study compares pulsatile and continuous-flow RVADs to assess their effects on cardiac function.

Purpose of the Study:

• To compare the effects of pulsatile versus continuous-flow RVADs on biventricular function.
• To determine if pulsatile RVADs are less detrimental to cardiac function than nonpulsatile pumps.
• To perform a load-independent analysis of biventricular function under RVAD support.

Main Methods:

• Sixteen dogs underwent instrumentation for biventricular pressure-dimension measurements.
• Right ventricular bypass was established using either a pulsatile (n=7) or continuous-flow (n=9) RVAD for 4 hours.
• Load-insensitive preload recruitable stroke work was calculated to assess biventricular function post-support.

Main Results:

• Neither pulsatile nor continuous-flow RVADs showed significant benefits in right or left ventricular function (RV PRSW index: 0.863 vs. 0.849; LV PRSW index: 0.880 vs. 0.821).
• Cardiac output and pulmonary vascular resistance did not differ significantly between the pulsatile and continuous-flow groups.
• No significant difference in myocardial performance was observed between the two RVAD types.

Conclusions:

• Pneumatically driven pulsatile RVADs do not offer additional myocardial performance benefits compared to conventional nonpulsatile pumps.
• Further investigation is required to define the potential role of pulsatile circulatory support devices.
• Current data suggest no superior functional advantage of pulsatile RVADs over continuous-flow devices.