The Consequence of Cardiovascular Sympathetic Nervous System in Obstructive Sleep Apnea / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The previous studies have shown that patients with obstructive sleep apnea (OSA) have shown high levels of cardiovascular diseases. These cardiovascular diseases are related to imbalance of cardiac autonomic systems. Alteration of QT interval in EKG reflects the increased cardiac sympathetic activity. The purpose of this study is to compare the cardiac sympathetic nerve activity between the control and OSA patients. SUBJECTS AND METHOD: All the patients were divided into the control group (n=20), whose RDI was less than 5 and the OSA group (n=40), whose RDI was more than 5. The OSA group was also divided into 3 groups, mild, moderate and severe, according to their RDI. The corrected QT interval (QTc) in EKG was checked at day time and during polysomnography. RESULTS: The number of hypertensive patients was significantly greater in the OSA group than the control group (p<0.001). The QTc interval was increased proportional to the RDI (p<0.001). There was a significant difference in the QTc intervals between the daytime period and apnea peak (p=0.031). CONCLUSION: Our results showed that the QT prolongation might be a prognostic factor in predicting the cardiac sympathetic hyperactivity in obstructive sleep apnea patients.