The Association of Functional Capacity With Right Atrial Deformation in Patients With Pulmonary Arterial Hypertension: A Study With Two-Dimensional Speckle Tracking

Abstract

Background: The purpose of this study was to assess right atrial (RA) myocardial mechanics in pulmonary hypertension (PH) patients using two-dimensional speckle tracking (2D-STE), and define the relationship between RA function and exercise capacity in PH patients.

Methods: Thirty-eight consecutive PH patients were studied and compared with a control group of 25 healthy volunteers. Peak atrial longitudinal strain (PALS), RA strain rate were measured in all subjects. PALS values were obtained by averaging all segments (global PALS), and by averaging segments measured in the four-chamber view.

Results: Right atrial PALS was significantly lower in PH patients than in controls, and gradually reduced with the development of cardiac insufficiency. A significantly positive correlation between global PALS and 6-minute walk distance (6MWD) was found (p=0.003). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.979) and excellent sensitivity and specificity of 86.8% and 84%, respectively, to predict functional status using a cut-off value less than 38.08%.

Conclusions: Right atrial deformation is significantly damaged in PH patients. Right atrial reservoir function can be estimated using 2D-STE, which gradually decreases in PH patients with different World Health Organization-functional class (WHO-FC). Right atrial PALS is a valuable factor for predicting the functional status and exercise capacity in PH patients.

Keywords: Longitudinal strain; Pulmonary hypertension; Right atrium; Speckle-tracking echocardiography.