What is the clinical evidence from this study?

Study design: Other. Population: Bioprosthetic heart valve leaflet fluttering. Intervention: Varying hemodynamic conditions (cardiac output, inflow, valve orientation). Primary outcome: Leaflet fluttering frequency and amplitude.

What does this research mean for the field?

Bovine bioprosthetic heart valve leaflet fluttering presents in two distinct modes—high-frequency tip vibrations and low-frequency travelling waves—which increase with higher cardiac output and are associated with specific vortex shedding patterns. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

November 14, 2025Annals of Biomedical Engineering2 citationsOpen Access

Modes of Leaflet Fluttering: Quantitative Characterization of a Bovine Bioprosthetic Heart Valve

SJSilje Ekroll Jahren BVBernhard Vennemann KBK Bornemann

Key Result

In vitro testing of a bovine bioprosthetic heart valve identified two modes of leaflet fluttering: high-frequency (150–380 Hz) tip vibrations and low-frequency (30–90 Hz) travelling waves, which increased with higher cardiac output.

Structured PICO

Population

In vitro and computational fluid-structure interaction study of a 21-mm bovine bioprosthetic heart valve to characterize leaflet fluttering modes under varying hemodynamic conditions.

Exposure

Varying experimental hemodynamic conditions including cardiac output (3.5 and 5.0 L/min), inflow modifications (exponential horn insert vs no insert), and rotational orientations.

Outcome

Quantitative characterization of leaflet fluttering modes (frequency, amplitude, and kinematics) and associated flow structures.

Bioprosthetic heart valve leaflet fluttering occurs in two distinct modes (high-frequency tip vibrations and low-frequency travelling waves) driven by fluid-structure interactions, which may contribute to structural valve deterioration.

Limitations

Use of only one bioprosthetic valve design and size
Flow loop did not mimic the complex flow pattern within the left ventricle
Aortic root model featured no coronary arteries
FSI study did not explore sensitivity to fluid viscosity, pulse waveform, and material parameters

Abstract

Oscillations of aortic bioprosthetic heart valve (BHV) leaflets during systole are known as leaflet fluttering (LF). LF may be relevant for assessing valvular function and could play a role in structural valve deterioration. However, a quantitative characterization of LF and its underlying physical processes is still missing. The objectives of this study are to systematically characterize LF for a BHV in vitro and to investigate the associated flow structures using a computational model. Leaflet motion of a bovine BHV was captured with high-speed cameras in an in vitro flow loop under varying experimental conditions (cardiac output (CO), inflow, and valve and aortic root orientation). A fluid-structure interaction (FSI) study was conducted for the same BHV for one condition to examine the blood flow patterns associated with LF. In vitro, LF presents in two different modes: either as high-frequency (150-380 Hz), low-amplitude (0.2-0.8 mm) vibrations of the leaflet tips (V-mode) or low frequency (30-90 Hz), high-amplitude (0.4-2.6 mm) waves travelling from leaflet base to tip (T-mode). We observed that LF depends on individual leaflet properties, is more likely to occur, and increases in amplitude and frequency with higher CO, and is also affected by the inflow. The FSI study confirms the presence of the same two modes. We identified large-scale vortex shedding related to the T-mode, superimposed with small-scale vortex shedding connected to vibrations of the leaflet tip (V-mode). Both identified LF modes are potential factors in BHV degeneration and should be considered in the BHV's design.

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