Comparison of left atrial volume and function in non-dipper versus dipper hypertensives: A real-time three-dimensional echocardiography study

OBJECTIVE: Non-dipper hypertension is associated with an increased cardiovascular morbidity and mortality. Besides this, the left atrial (LA) size and functions are accepted to be prognostic factors in various cardiovascular diseases. In this study, we aimed to evaluate the effect of nondipper hypertension on LA volume and functions using real-time three-dimensional echocardiography (RT3-DE). METHODS: Forty dipper and 52 non-dipper hypertensives enrolled in this prospective cross-sectional study. Patients with any comorbidities that have a potential for causing structural cardiac alterations were excluded. Two-dimensional echocardiography (2-DE) and RT3-DE were performed to assess LA volumes and functions. The statistical tests used in this study were Shapiro-Wilk's test, Student's t-test, Mann-Whitney U test, chi-square test, Spearman's test, and Pearson's correlation test. RESULTS: LA minimal volume, LA volume before LA contraction, and LA total systolic volume were higher in non-dipper hypertensives than in dipper hypertensives (p<0.001, p=0.003, and p=0.03, respectively). Only, the 2-DE measurements of interventricular septal thickness and E/Em ratio were higher in non-dipper hypertensives (p=0.001 and p=0.03, respectively). There was a moderate correlation between LA minimal volume and LA volume before LA contraction with E/Em (r=0.31, p=0.007 and r=0.32, p=0.005, respectively). CONCLUSION: Although LA volume and passive LA systolic functions measured by RT3-DE are significantly increased in non-dipper hypertensives, the alterations in active LA systolic functions are not prominent. RT-3DE may be used to define LA volume and function alterations in conditions that have capabilities of adverse cardiac remodeling such as systemic hypertension.