Left atrial function and deformation in chronic primary mitral regurgitation

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• Chronic primary mitral regurgitation (MR) affects left atrial (LA) function.
• Understanding global and regional LA mechanics is crucial for assessing MR severity and impact.

Purpose of the Study:

• To investigate global and regional left atrial (LA) mechanics in patients with chronic primary mitral regurgitation (MR) using echocardiography.
• To correlate LA deformation parameters with volumetric changes and assess the contractile contribution to left ventricular filling.

Main Methods:

• Echocardiographic assessment of LA volumes and dimensions in reservoir, conduit, and contractile phases.
• Calculation of LA ejection fraction (EF), ejection force, strain rates (SR-R, SR-C, SR-A), and reservoir phase strain.
• Comparison of these parameters between 27 MR patients and 25 controls.

Main Results:

• Patients with MR exhibited higher LA volumes in all phases compared to controls.
• Increased LA ejection force, reservoir phase strain, and strain rates (SR-R, SR-C, SR-A) were observed in MR patients.
• Despite enhanced LA strain rates, LA ejection fraction (EF) was unchanged, and LA contractile tissue velocity (A') was reduced in MR patients, signifying a diminished contractile contribution to left ventricular filling.

Conclusions:

• Left atrial (LA) deformation is globally and regionally increased in chronic primary mitral regurgitation (MR).
• The unchanged LA ejection fraction (EF) and reduced LA contractile velocity (A') suggest a compromised contractile contribution to left ventricular filling despite compensatory hyperdeformation.