Load Dependency of Left Atrial Strain in Normal Subjects

Area of Science:

• Cardiology
• Cardiac Physiology
• Echocardiography

Background:

• Left atrial (LA) longitudinal strain is a novel parameter for evaluating LA function with prognostic value in cardiac diseases.
• The load dependency of LA strain is not well understood.
• This study aimed to assess the impact of acute preload changes on LA strain and volume.

Purpose of the Study:

• To evaluate the preload dependency of Left Atrial (LA) strain.
• To compare the load dependency of LA strain with LA volume.
• To investigate LA function in healthy subjects under varying preload conditions.

Main Methods:

• Twenty-five healthy volunteers underwent echocardiographic imaging.
• Acute preload reduction was induced using a tilt maneuver (0°, 40°, 80°).
• LA strain components (reservoir, conduit, contractile) and LA volumes were measured using speckle-tracking and standard methods.

Main Results:

• Progressive tilt resulted in significant decreases in LA volumes, LV volumes, and LVEF.
• LA reservoir, conduit, and contractile strain values significantly decreased with preload reduction.
• Percentage changes in LA reservoir strain were smaller compared to changes in LA maximum volume.

Conclusions:

• Left atrial strain is preload dependent in healthy individuals.
• LA strain exhibits less load dependency compared to LA volume.
• LA strain may offer a relative advantage over LA maximum volume in diagnostic assessments.