Do left atrial strain and strain rate reflect intrinsic atrial function, or are they determined by left ventricular...

Area of Science:

• Cardiology
• Biomedical Engineering
• Cardiac Imaging

Background:

• Left atrial (LA) strain (S) and strain rate (SR) are recognized indicators of intrinsic cardiac function.
• The anatomical connection between the LA and left ventricle (LV) via the mitral annulus suggests a potential relationship in their mechanical behavior.

Purpose of the Study:

• To determine if LA deformation indices are primarily predicted by LV deformation.
• To compare the timing of S and SR events between the LA and LV.
• To investigate if alterations in LA and LV S and SR are similar in patients with predominant LV dysfunction.

Main Methods:

• Retrospective analysis of 50 asymptomatic women (Group 1) and 20 patients with acute pulmonary edema (Group 2).
• Utilized speckle tracking echocardiography to measure the amplitude and timing of LA and LV S and SR from three apical views.
• Cardiac cycle analysis initiated from the P-wave.

Main Results:

• In asymptomatic subjects, LA deformation indices were significantly higher than LV indices (p < 0.001).
• In patients with pulmonary edema, LA S and SR during LA contraction were higher than LV (p < 0.05), but other indices showed no significant difference.
• LA and LV S and SR timings were largely simultaneous, with a minor exception for LA contraction S in asymptomatic individuals.
• LV deformation indices were the strongest predictors of LA deformation indices, particularly in patients with LV dysfunction (r = 0.76-0.85).

Conclusions:

• LA deformation is a strong indicator of LV deformation in both healthy individuals and those with LV dysfunction.
• Distinguishing intrinsic LA function from the influence of LV mechanics is difficult using deformation analysis, except possibly during LA contraction in asymptomatic subjects.