Chronic effect of left ventricular assist pumping on right ventricular function

Area of Science:

• Cardiovascular Science
• Medical Devices
• Heart Failure Research

Background:

• Left ventricular assist devices (LVADs) are crucial for managing advanced heart failure.
• Understanding the impact of LVADs on right ventricular (RV) function is essential for patient outcomes.
• Previous research has not fully elucidated RV response to LVAD support in various cardiac conditions.

Purpose of the Study:

• To evaluate RV function during LVAD support in both acute and chronic settings.
• To investigate the effects of LVAD pumping on RV hemodynamics in normal and failing left ventricles.
• To determine the long-term impact of LVADs on RV dimensions and function.

Main Methods:

• Implantation of an LVAD between the left atrium and descending aorta in goats.
• Conducting acute and chronic experiments (4-6 weeks) with LVADs in counterpulsation and maximum bypass modes.
• Utilizing sonomicrometry to measure RV free-wall segment dimensions and assess RV function.

Main Results:

• LVAD pumping did not negatively affect RV function, even after 6 weeks of support.
• A gradual, small increase in RV free-wall dimensions was observed postoperatively, attributed to increased RV volume return and LV volume reduction.
• Similar RV dimensional changes were noted in hearts with pre-existing left ventricular failure.

Conclusions:

• LVADs can potentially assist RV function by reducing RV afterload.
• Prolonged and excessive LVAD support may lead to RV free-wall dilation.
• Preexisting RV dysfunction is identified as the primary cause of RV failure during LVAD therapy.