Cardiac fluid dynamics anticipates heart adaptation

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Physics

Background:

• Hemodynamic forces act as epigenetic factors influencing heart development and pathology.
• Cardiac blood flow exhibits vortical dynamics, believed to play a role in disease progression or regression.

Purpose of the Study:

• To demonstrate the relevance of maladaptive intra-cardiac vortex dynamics in the geometrical adaptation of a dysfunctional heart.
• To investigate the role of hemodynamic forces as an early indicator of cardiac changes.

Main Methods:

• Utilized an in vivo model of patients undergoing cardiac resynchronization therapy (CRT).
• Analyzed intra-ventricular fluid dynamics using echocardiography with Particle Image Velocimetry (Echo-PIV).
• Temporarily switched off biventricular pacemakers to observe changes in flow dynamics.

Main Results:

• Under normal conditions (CRT on), intraventricular hemodynamic forces showed longitudinal alignment.
• When CRT was switched off, flow forces misaligned, impacting lateral walls without other immediate electro-mechanical changes.
• Misaligned hemodynamic forces were identified as the initial event preceding physiological activity and cardiac adaptation.

Conclusions:

• Maladaptive intra-cardiac vortex dynamics are relevant to geometrical adaptation in dysfunctional hearts.
• Hemodynamic forces emerge as an early physiological event that anticipates cardiac changes.
• This understanding may aid in predicting longer-term heart adaptations and disease progression.