Effect of Heart Valve Replacement on Cheyne-Stokes Respiration (CSR)

• Changes of CSR index before and 3, 6, 12 months following valve replacement. [ Time Frame: 1 year after cardiac surgery of each enrolled patient ] [ Designated as safety issue: Yes ]
  The primary goal of this study is to compare the changes of polysomnography(PSG) parameters(index of CSR, apnea hypopnea index, pulse oxygen saturation, etc)before and 3, 6, 12 months following the cardiac valve replacement surgery.
  
  

• Association of PSG parameters with cardiac function before and 3, 6, 12 months following valve replacement [ Time Frame: 1 year after cardiac surgery of each enrolled patient ] [ Designated as safety issue: Yes ]
  The secondary goal of this study is to determine the association of PSG parameters(index of CSR, apnea hypopnea index, pulse oxygen saturation, electrocardiogram, etc)and cardiac function (LVEF, 6-minute walk test, etc) before and 3, 6, 12 months following the cardiac valve replacement surgery. Qualities of life and sleep will also be masured before and 3, 6, 12 months after surgery. (The quality of life is assessed by reference to "The Medical Outcomes Study 36item Short-Form Health Survey"(SF-36) generic questionnaire, and sleep quality is assessed by Pittsburgh Sleep Quality Index(PSQI).)
  
  

Sleep apnea, especially central sleep apnea, has a high prevalence in patients with chronic heart failure. Although sleep disordered breathing (SDB) have been described in patients with heart disease, the prevalence is not known because: ①There are various forms of SDBs, including obstructive sleep apnea(OSA), central sleep apnea (CSA), and mixed forms of sleep apnea syndromes that have variable prevalence; ②Patients suffering from rheumatic valve disease usually have varying degrees of heart failure, and this variability affects estimates of prevalence; ③There are no international patient registries and SDB is underdiagnosed in many parts of the world.

The previous studies are most focusing on nonvalvular disease. We ①investigate the prevalence and the risk factors of Cheyne-Stokes respiration in patients with heart valve diseases, ②compare the changes of parameters of Cheyne-Stokes Respiration and heart function (like apnea hypopnea index, pulse oxygen saturation, blood pressure, echocardiogram, electrocardiogram, 6-minute walk test) before heart valve replacement and 3, 6, and 12 months after the surgery.

With nocturnal polysomnography (PSG) examination 30 patients typical CSR are going to be screened out from 300 patients with heart valve disease and waiting for cardiac surgery. The Comparison of 30 patients undergoing heart valve replacement will be performed before and 3, 6, and 12 months following heart valve replacement. We shall analyze the changes of CSR before and after valve replacement as well as the correlation among cardiac function and PSG parameters.