The relation between mitral annulus motion and left ventricular ejection fraction in atrial fibrillation

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Physiology

Background:

• Mitral annulus motion (MAM) is a novel index for assessing left ventricular (LV) function.
• Previous studies established agreement between MAM and ejection fraction (EF) in sinus rhythm patients.
• Atrial fibrillation (AF) patients were excluded from prior MAM research.

Purpose of the Study:

• To investigate the relationship between MAM and EF in patients with atrial fibrillation.
• To determine if the conversion factor for estimating LV function using MAM differs in AF patients compared to controls.

Main Methods:

• Echocardiographic assessment of mitral annulus motion (MAM) and ejection fraction (EF).
• Comparison of MAM and EF between patients with atrial fibrillation and age-matched controls in sinus rhythm.
• Calculation of the EF/MAM conversion factor for both groups.

Main Results:

• Mitral annulus motion (MAM) was significantly reduced in patients with atrial fibrillation compared to sinus rhythm controls.
• Ejection fraction (EF) did not differ between the atrial fibrillation and control groups.
• The EF/MAM conversion factor was higher (7.2) in atrial fibrillation patients versus controls (5.1).
• Patients with AF exhibited lower stroke volume and higher heart rate.

Conclusions:

• The established conversion factor for MAM to estimate EF requires adjustment in patients with atrial fibrillation.
• Reduced systolic long-axis shortening in AF patients contributes to altered MAM.
• Accurate assessment of LV function using MAM in AF requires consideration of these differences.