Relationship between obstructive sleep apnea severity index and left ventricular function and volume

Abstract

BACKGROUND AND OBJECTIVESObstructive sleep apnea (OSA) causes increased cardiovascular morbidity and mortality, including systemic arterial hypertension, coronary heart disease, heart rhythm and conduction disorders, heart failure and stroke. In our study, we aimed to assess left ventricular mass and myocardial performance index (MPI) in OSA patients.DESIGN AND SETTINGA cross-sectional study conducted between May 2007 and August 2009 in a tertiary hospital in Istanbul, Turkey.PATIENTS AND METHODSForty subjects without any cardiac or pulmonary disease referred for evaluation of OSA had overnight polysomnography and echocardiography. According to the apnea-hypopnea index (AHI), subjects were classified into three groups; mild OSA (AHI: 5–14/h; n=7), moderate OSA (AHI: 15–29/h; n=13), and severe OSA (AHI: ≥30/h; n=20). The thickness of the interventricular septum (IVS) and left ventricular posterior wall (LVPW) were measured by M-mode along with left ventricular mass (LVM) and LVM index (LVMI). The left ventricular MPI was calculated as (isovolumic contraction time + isovolumic relaxation time)/aortic ejection time by Doppler echocardiography.RESULTSNo differences were observed in age or body mass index among the groups, but blood pressures were higher in severe OSA compared with moderate and mild OSA. In severe OSA, the thickness of the IVS (11.6 [1.7 mm]), LVPW (10.7 [1.7 mm]), LVM (260.9 [50.5 g]), and LVMI (121.9 [21.1g/m2]) were higher than in moderate OSA (9.4 [1.3 mm]; 9.9 [1.6]; 196.4 [35.2]; 94.7 [13.2 g/m2], respectively) and mild OSA (9.8 [2.4 mm], 8.9 [2.0 mm], 187.6 [66.2 g], 95.8 [28.6 g/m2], respectively). In severe OSA, MPI (0.8 [0.2]) was significantly higher than in mild OSA (0.5 [P<.01]) but not significantly higher than moderate OSA (0.8 [0.1]).CONCLUSIONSOSA patients have demonstrable cardiac abnormalities that worsen with the severity of apnea. The MPI may have utility in subsequent OSA studies, possibly as a surrogate outcome measure.

Tıkayıcı uyku apnesi olan hastalarda ekokardiyografik değerlendirme polisomnografi için daha doğru hasta seçimi sağlayabilir: Ekokardiyografi ile hastalığın şiddetini tahmin etme

“…Additionally, severe OSA patients showed a significant increase in LVMI. This is in line with previous studies on this topic [20]. It is known that intermittent hypoxia causes left ventricular hypertrophy and also plays an important role in the cardiovascular complications of OSA [21].…”

Effect of Severe Obstructive Sleep Apnea on Morphology of Left-Sided Heart and Pulmonary Artery Pressure

“…This has been reported earlier also and suggests higher left ventricular afterload consequent to obstructive sleep apnea [27,28]. Left ventricular hypertrophy, which is commonly seen in patients with systemic hypertension has been reported in subjects with obstructive sleep apnea even in absence of systemic hypertension [29].…”

Prevalence of obstructive sleep apnea in surgical patients presenting to a tertiary care teaching hospital in India: A preliminary study

“…It should be noted that untreated OSA is an independent risk factor for cardio-vascular illness through a myriad of mechanisms. [1920] However, the condition is reversible and treatment of OSA was found to decrease the incidence of cardio-vascular disorders. [21] OSA is also known to impair glycemic control that was found to improve with the treatment.…”