E-wave generated intraventricular diastolic vortex to L-wave relation: model-based prediction with in vivo validation

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Imaging

Background:

• L-waves, observed alongside Doppler echocardiographic E-waves, are associated with diastolic dysfunction.
• The precise mechanisms generating L-waves remain incompletely understood.
• A hypothesis proposes that recirculating intraventricular vortex rings are responsible for L-wave formation.

Purpose of the Study:

• To investigate the mechanism of L-wave generation.
• To predict and confirm the presence of L-waves in the right ventricle (RV).
• To elucidate the role of intraventricular vortex rings in diastolic fluid mechanics.

Main Methods:

• Doppler echocardiography and phase-contrast magnetic resonance imaging (PC-MRI) were used to image intraventricular flow.
• Studies were conducted on 10 healthy volunteers.
• Three-dimensional intraventricular flow patterns were analyzed using PC-MRI.

Main Results:

• L-waves were detected in all subjects, with peak velocities typically found 2 cm below the annulus.
• L-waves occurred in 55% of cardiac cycles analyzed.
• PC-MRI confirmed the hypothesis, and L-waves were observed in both the left and right ventricles (LV and RV).

Conclusions:

• The re-entry of E-wave-generated vortex ring flow is the mechanism for imaging L-waves.
• L-waves are a common feature resulting from LV and RV diastolic fluid dynamics.
• The findings provide a new understanding of diastolic function and potential markers for dysfunction.