Abstract 2552: Altered Myocardial Characteristics and Function in Patients with Obstructive Sleep Apnea Evaluated by Myocardial Integrated Backscatter and Tissue Doppler imaging.
Background: It has been suggested that patients with obstructive sleep apnea (OSA) have subclinical myocardial dysfunction that may account for their risk of heart failure. This study sought to examine whether myocardial characteristics and function, as determined by echocardiographic integrated backscatter and tissue Doppler imaging, might be altered in patients with OSA.
Methods: Thirty-seven patients with suspected OSA (32 men and 5 women) underwent clinical evaluation, overnight polysomnography, and echocardiographic assessment. For assessing subclinical myocardial function, the myocardial reflectivity (integrated backscatter intensity) of the ventricular septum (IBI-sp) and posterior wall (IBI-pw), and the systolic (Sa) and diastolic (Ea) velocity at the mitral annulus were obtained. Variables were compared between patients with apnea-hypopnea index (AHI) <15 (n=17) and those with AHI ≥15 (n=20).
Results: Although age and global parameters of LV function were similar, moderate-to-severe OSA patients had greater LV mass index, lower Ea, and higher myocardial reflectivity. The myocardial reflectivity (IBI-sp, r=0.45, p<0.01; IBI-pw, r=0.56, p<0.001) and Ea (r=−0.40, p<0.05) correlated significantly with AHI independent of LV mass index.
Conclusions: OSA can affect myocardial integrity as well as myocardial diastolic function. More frequent hypoxic events during sleep appear to accelerate myocardial disease in OSA patients.