Mechanical heart valve performance in a pulsatile pediatric ventricular assist device

Area of Science:

• Biomedical Engineering
• Cardiovascular Device Development
• Pediatric Cardiac Support

Background:

• Pediatric ventricular assist devices (VADs) are crucial for managing heart failure in children.
• Optimizing valve performance in VADs is essential for improving patient outcomes.
• Development of a novel 12 ml dynamic stroke volume pulsatile pediatric VAD is ongoing.

Purpose of the Study:

• To compare the hydrodynamic performance of a monoleaflet valve (Monostrut) and a bileaflet valve (CPHV) in a pulsatile pediatric VAD.
• To evaluate the impact of varying heart rate and systolic duration on valve function.
• To determine valve suitability for pediatric VAD applications.

Main Methods:

• Utilized a high-speed video and data acquisition system for simultaneous recording.
• Measured video images, pressure waveforms, and flow waveforms under various in vitro conditions.
• Tested both Björk-Shiley Monostrut (monoleaflet) and CarboMedics Prosthetic Heart Valve (CPHV, bileaflet) in horizontal and vertical orientations, and inlet/outlet positions.

Main Results:

• CPHV exhibited larger regurgitant volumes than Monostrut valves across all tested conditions and positions.
• CPHV demonstrated higher stroke volumes and cardiac outputs at increased heart rates and longer systolic durations.
• Monostrut valve hydrodynamic performance was more sensitive to operational condition changes compared to CPHV.

Conclusions:

• The bileaflet CPHV shows potential for higher cardiac output in pediatric VADs, particularly at higher operating rates.
• Valve selection requires careful consideration of regurgitant volume versus cardiac output trade-offs.
• Further research is needed to identify optimal operating conditions for both valve types in this specific pediatric VAD.