Left atrial geometry and pump function in ischemic cardiomyopathy

Abstract

Background: Many of the factors that are known to alter left atrial (LA) contractility are present in patients with ischemic cardiomyopathy (ICM). Nevertheless, preservation of LA contractile function in this group of patients was reported in previous studies. The aim of this study was to assess the changes in LA size, geometry and contractile function in ICM.

Methods and results: 60 subjects (age: 49 ± 12 years, 53% males) in sinus rhythm undergoing coronary angiography (CA), were enrolled in this study; 15 subjects as a control group, 30 patients with reduced ejection fraction (EF) and significant coronary artery disease; as the ICM group, and 15 with reduced EF and normal CA; as the dilated cardiomyopathy (DCM) group. LA dimensions, volume, active emptying fraction (ACTEF) and eccentricity index (LAEi) as well as late diastolic velocities of the mitral annulus (a') and LA free wall (A₃) were measured. Compared with the control group, ICM patients had larger LA volume and reduced ACTEF, a' and A₃, with no significant difference between patients with ICM and DCM in any of these parameters. LA eccentricity was, non-significantly, higher in both cardiomyopathy groups than in the control group.

Conclusions: Patients with ICM have increased LA volume and reduced LA contractile function in comparison with normal controls. LA enlargement, LA contractile dysfunction and LA geometric changes in ICM are similar to that occurring in DCM. LA size, contractile function and eccentricity may not be reliable in differentiating ischemic from idiopathic dilated cardiomyopathy.

Keywords: Atrial eccentricity; Echocardiography; Heart failure; Ischemic cardiomyopathy; Left atrial function.

Fig. 1

Left; left atrial volume measured using biplane (apical four, upper, and two chamber, lower, views) area–length method. Right; left atrial antero-posterior (upper), superior–inferior and medio-lateral (lower) diameters.

Fig. 2

Correlation plot between left atrial maximum volume (LA V_max) and left atrial active emptying fraction (ACTEF) in ischemic cardiomyopathy patients.

Fig. 3

Ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) did not differ significantly in left atrial active emptying fraction (LA ACTEF), septal a′ or left atrial late diastolic velocity (LA A₃). On the other hand, cardiomyopathy patients with restrictive filling pattern (RFP) had lower indices of LA contractility than those without RFP. *RFP vs Non-RFP; P value for ACTEF was 0.057. P value for septal a′ and LA A3 was < 0.05.