Association of Presystolic Wave with Subclinical Left Ventricular Dysfunction in Obstructive Sleep Apnea Syndrome

Abstract

Background: Obstructive sleep apnea syndrome (OSAS) is associated with subclinical myocardial dysfunction. This study aimed to evaluate the association between presystolic wave (PSW) and left ventricular global longitudinal strain (GLS) in patients with confirmed OSAS and to determine whether PSW may serve as a simple echocardiographic marker of subclinical left ventricular systolic dysfunction. Methods: A total of 103 patients with polysomnography-confirmed OSAS were prospectively enrolled. Patients were classified according to the presence or absence of PSW. Clinical characteristics, polysomnographic findings, conventional echocardiographic parameters, and left ventricular GLS obtained by two-dimensional speckle-tracking echocardiography were compared between groups. Univariable and multivariable logistic regression analyses were performed to identify factors independently associated with the presence of PSW. Results: Fifty-seven patients were classified as PSW-positive and 46 as PSW-negative. Patients with PSW had significantly higher apnea-hypopnea index values and a greater prevalence of severe OSAS. Although left ventricular ejection fraction remained within the normal range in both groups, GLS was significantly impaired in PSW-positive patients (-16.1 +/- 1.9% vs. -18.1 +/- 1.3%, p < 0.001). In multivariable logistic regression analysis, GLS remained independently associated with PSW presence after adjustment for apnea-hypopnea index, body mass index, waist circumference, and beta-blocker use (OR, 2.19; 95% CI, 1.52-3.15; p < 0.001). Among patients with detectable PSW, the median peak PSW velocity was 65 cm/s (interquartile range, 57-70 cm/s) and was not significantly correlated with GLS or apnea-hypopnea index. Conclusions: In patients with OSAS, the presence of a PSW is independently associated with impaired GLS despite preserved left ventricular ejection fraction. These findings suggest that PSW may serve as a simple, non-invasive, and readily available echocardiographic marker of subclinical left ventricular systolic dysfunction in this population.