Apical left ventricular asynergy in chronic aortic regurgitation

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Physiology

Background:

• Apical left ventricular (LV) wall motion abnormalities are noted in chronic volume overload conditions.
• The precise nature of these abnormalities, specifically hypokinesia, requires detailed investigation.

Purpose of the Study:

• To evaluate apical LV wall motion abnormalities in patients with pure aortic regurgitation (AR).
• To determine if reduced apical function in AR represents actual hypokinesia and impaired contractility.

Main Methods:

• Assessed percent shortening of apical LV radiants (PS%) using computerized angiography.
• Utilized M-mode echocardiography to measure endocardial systolic movement (ESM) and thickening (%Th) in the apical region.
• Analyzed 11 patients with pure aortic regurgitation.

Main Results:

• Patients with AR showed significantly reduced apical radii shortening, %Th, and ESM compared to normal subjects.
• %Th and ESM directly correlated with PS%, indicating a link between different measures of apical function.
• PS% correlated with systolic eccentricity and end-systolic volume index, suggesting altered LV geometry.
• %Th correlated with normalized peak rates of systolic wall thickening and diastolic wall thinning.

Conclusions:

• Reduced apical radii shortening in AR is associated with impaired systolic wall thickening and diastolic wall thinning rates.
• These findings indicate actual hypokinesia and impaired contractility in the apical LV region of AR patients.
• The observed abnormalities are linked to altered LV dynamic geometry resulting from chronic volume overload.