Right ventricular dysfunction in patients with obstructive sleep apnoea syndrome

Abstract

There is conclusive evidence that obstructive sleep apnoea syndrome (OSAS) influences right heart haemodynamics and can also induce pulmonary hypertension. It is not known, however, whether right ventricular dysfunction can occur in patients with OSAS in the absence of lung disease.We studied 107 patients (94 males, 13 females, mean age 55±11 yrs) with polysomnographically verified OSAS in whom clinically significant lung disease was excluded. Right ventricular ejection fraction (RVEF) was determined by radionuclide ventriculography. In addition, pulmonary function tests, arterial blood gas analysis and right heart catheterization were performed. RVEF was impaired in 19 patients (18%). Eighteen (95%) had signs or symptoms consistent with mild right ventricular failure. Patients with or without impaired RVEF did not differ with respect to body mass index, age or lung function. Stepwise multiple logistic regression analysis revealed that RVEF was significantly associated with the apnoea/hypopnoea index (r=-0.68; p=0.0009) and the extent of nocturnal oxyhaemoglobin saturation (r=0.42; p=0.035), but not with age, body mass index, blood gas analysis, gender, lung function, pulmonary artery pressure and left ventricular ejection fraction.We conclude that in patients with otherwise unexplained right ventricular failure, obstructive sleep apnoea syndrome may underlie the right ventricular dysfunction. Eur Respir J 1997; 10: 2079-2083 Obstructive sleep apnoea syndrome (OSAS) is a common condition characterized by repeated pauses (apnoeas) or reductions (hypopnoeas) in breathing during sleep [1]. It is caused by a complete or partial upper airway obstruction, which leads to increasing pleural pressure swings, decreases in oxyhaemoglobin saturation and subsequent arousal from sleep, whereupon airway patency is restored and airflow resumes.These mechanisms seem to be responsible for a series of secondary physiological events, which in turn give rise to the clinical complication of the syndrome and probably associated cardiovascular disease [2,3].While episodic nocturnal pulmonary hypertension in OSAS is well described [4,5], the consequences of OSAS with respect to the function of the right ventricle are less well studied [6][7][8][9]. Right ventricular dysfunction occurring in patients with OSAS has generally been attributed to concomitant chronic obstructive lung disease, hypercapnia, or at least mild hypoxia [8,[10][11][12]. As yet, no direct association between OSAS and right ventricular dysfunction is known. To examine this question, the prevalence of right ventricular dysfunction and parameters possibly influencing right ventricular function were studied in a group of OSAS patients in whom an intrinsic pulmonary disorder was excluded. Methods Study designOne hundred and seven consecutive patients (94 males, 13 females) referred to our sleep laboratory for snoring, suspected OSAS, or excessive daytime sleepiness with a mean age of 55±11 yrs (range 28-74) and a mean body mass index (BMI) of 31-52 kg·m -2 (rang...

Relation Between Obesity, Metabolic Syndrome, Successful Long-Term Weight Reduction, and Right Ventricular Function

“…5,27,28) In these cases, impaired RV function is seen independently of pulmonary hypertension. [29][30][31] Indeed, available data on impaired RV function of obese patients were frequently acquired from predominantly severely obese patients, who also have concomitant OSA. However, a positive correlation of sleep breathing disorder with right ventricular wall thickness was described without significant differences in right atrial dimensions, RV dimensions, and RV systolic function.…”

Obesity and Right Ventricular Structure and Function

“…SDB was not assessed with polysomnography, and the sensitivity and specifi city of the questions used are not clear, so residual confounding could be present. [37][38][39][40] MESA excluded individuals with weight . 300 pounds, so that morbidly obese individuals in the study may have been less than those in the general population.…”

The rheological properties of blood and the risk of cardiovascular disease in patients with obstructive sleep apnea syndrome (OSAS)

“…The release of catecholamines which accompanies awakenings [32] may contribute to the change of rheological properties. Decrease of the number of apnea and hypopnea episodes to the level of physiological breathing with the aid of CPAP reduces the ability of platelet aggregation in conjunction with the change in levels of catecholamines [33,34].…”