Dursunoglu Dursun, Dursunoglu Nese
Pamukkale University Medical Faculty, Department of Cardiology, 20200 Kinikli, Denizli, Turkey.
Sleep Med. 2007 Aug;8(5):478-83. doi: 10.1016/j.sleep.2006.08.002. Epub 2007 May 18.
Delayed cardiac repolarization leading to prolongation of the QT interval is a well-characterised precursor of arrhythmias. Obstructive sleep apnea (OSA) might cause arrhythmias, since QT corrected interval dispersion (QTcd) is increased in these patients. We aimed to determine the effect of nasal continuous positive airway pressure (CPAP) therapy on QTcd in OSA patients without hypertension.
An overnight polysomnography (PSG) and a standard 12-lead electrocardiogram (ECG) were performed on 49 subjects without hypertension, diabetes mellitus, cardiac or pulmonary disease or any hormonal, hepatic, renal or electrolyte disorders. In 29 moderate-severe OSA (apnea-hypopnea index: AHI15) patients, QTd (defined as the difference between the maximum and minimum QT interval) and QTcd were calculated using the Bazzet formula at baseline and after six months of CPAP therapy.
Eighteen patients were compliant with nasal CPAP, and mean age was 46.5+/-4.9 years. Patients had high body mass index (BMI: 30.6+/-4.0 kg/m(2)), but there was no change in either BMI or blood pressure after six months. A strong positive correlation was shown between QTcd and AHI (p<0.001, r=0.913). The QTcd at baseline (54.5+/-8.7 ms) significantly decreased after CPAP therapy (35.5+/-4.2 ms, p<0.001), although it did not significantly change in 11 non-compliant patients.
In OSA patients without hypertension, CPAP therapy improves the inhomogeneity of repolarization via a significant decrease in QTcd.
延迟性心脏复极导致QT间期延长是一种特征明确的心律失常先兆。阻塞性睡眠呼吸暂停（OSA）可能会引发心律失常，因为这些患者的校正QT间期离散度（QTcd）会增加。我们旨在确定鼻持续气道正压通气（CPAP）治疗对无高血压的OSA患者QTcd的影响。
对49名无高血压、糖尿病、心脏或肺部疾病以及任何激素、肝脏、肾脏或电解质紊乱的受试者进行了整夜多导睡眠图（PSG）检查和标准12导联心电图（ECG）检查。在29名中重度OSA（呼吸暂停低通气指数：AHI≥15）患者中，使用Bazzet公式在基线和CPAP治疗6个月后计算QTd（定义为最大和最小QT间期之差）和QTcd。
18名患者依从鼻CPAP治疗，平均年龄为46.5±4.9岁。患者的体重指数较高（BMI：30.6±4.0kg/m²），但6个月后BMI和血压均无变化。QTcd与AHI之间显示出强正相关（p<0.001，r=0.913）。CPAP治疗后，基线时的QTcd（54.5±8.7ms）显著降低（35.5±4.2ms，p<0.001），尽管11名不依从患者的QTcd没有显著变化。
在无高血压的OSA患者中，CPAP治疗通过显著降低QTcd改善了复极的不均一性。
