Evidence of atrial mechanical dysfunction by acoustic quantification in abnormal relaxation and restrictive filling patterns of diastolic dysfunction in patients with coronary artery disease.

Abstract

This study made use of acoustic quantification (AQ) to investigate if left atrial (LA) mechanical function was impaired in patients with diastolic dysfunction, which might not be detected by conventional Doppler echocardiography. One hundred and ten patients with coronary artery disease (mean age 65+/-11 years, 80% male) underwent echocardiography prospectively while AQ was performed using harmonic imaging at the apical four-chamber view to evaluate LA function. By Doppler echocardiography, left ventricular (LV) diastolic dysfunction in the form of abnormal relaxation pattern (ARP) was present in 84, pseudonormal (PN) in nine and restrictive filling pattern (RFP) in 10 patients. LA mechanical dysfunction with impaired total fractional area change (FAC) of </=20% was present in 17/19 (89%) patients in the RFP/PN group, but was observed in 27/84 (32%) patients with ARP. Despite identical diastolic Doppler indices between patients with ARP with preserved (n=57) and impaired total FAC, the latter group had significantly lower LV ejection fraction (P<0.001), larger LV volumes (P<0.05 and 0.002, respectively), as well as larger LA area (P<0.001) and lower LA peak emptying and filling rates (both P=0.001). In contrast, there was no difference in nearly all of the parameters of LA function, LV systolic function and LV volume between patients with RFP/PN and ARP with FAC </=20%. Both active and passive LA pump functions were impaired in patients with RFP/PN or ARP with FAC </=20%. LA mechanical dysfunction was found to be present in one-third of the patients with ARP of diastolic dysfunction despite a high MV-A. It was also present in almost all the patients with RFP/PN pattern of diastolic dysfunction. Therefore, AQ may provide information on atrial mechanical function complementary to that of Doppler echocardiography.