Factors influencing left atrial volume in treated hypertension

Abstract

Background: Left atrial (LA) enlargement has been documented to occur in hypertension (HT), and has been an index for evaluating the diastolic function of the left ventricle. Enlargement of the LA is one of the vital factors that induce heart failure and atrial fibrillation (AF) in patients with HT.

Methods and subjects: 130 treated hypertensive patients were enrolled. All recruits participated in an echocardiogram, electrocardiogram, a routine blood examination including brain natriuretic peptide (BNP), and physical examinations.

Results: Left ventricular mass (LVM) indexed to height(2.7) had a significant positive correlation with left atrial volume index (LAVI) (p<0.0001), as well as natural logarithm BNP (p<0.001). Blood pressure levels were not associated with LAVI, neither body mass index nor age. LAVI had a positive correlation with factors involving the left ventricle volume, LVM, and right ventricle systolic pressure (RVSP) (r=0.687, p<0.0001). The parameters of LV diastolic function were positively but weakly associated with LA size. In the subgroup of LAVI, the evidence of paroxysmal atrial fibrillation (PAF): LAVI<32 ml/m(2) had no PAF, whereas the incidence of PAF was 7.5%, 11.4%, and 15.2%, respectively in the LAVI>32 ml/m(2) group. Of anti-hypertension drugs, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers had a tendency to reduce LAVI; however, there was no statistical significance within the groups.

Conclusions: Left ventricular volume and mass are independent factors affecting LAVI in treated HT. The incidence of PAF is associated with LA size. In patients with treated HT, LA size may be a useful surrogate marker for monitoring the effectiveness of medical therapy and occurrence of AF.