Cardiac Syndrome X, Endothelial Dysfunction, Obstructive Sleep Apnea
Conditions
Brief summary
Cardiac syndrome X consists of a triad of chest pain, abnormal exercise stress testing and normal coronary angiogram, and is hypothesized to be related to endothelial dysfunction. Endothelial dysfunction is also reported to be linked to obstructive sleep apnea. While chest pain can be one of potential presenting symptoms of obstructive sleep apnea, the investigators hypothesize that obstructive sleep apnea is common in subjects with cardiac syndrome X.
Interventions
no intervention is involved in this study
Sponsors
The University of Hong Kong
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Age ≧18 years, \< 70 years * Symptom of chest pain occurring at least once in the preceding year * Positive exercise treadmill test * Negative coronary angiogram * Mentally fit to give informed consent
Exclusion criteria
* Mentally incapacitated persons * Congestive heart failure * Other potential causes of orthopnea (severe chronic obstructive pulmonary disease, persistent asthma)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| apnea hypopnea index | measure at a single time point when the subjects are admitted for overnight polysomnography | assess apnea hypopnea index by overnight polysomnography, by a single admission to sleep laboratory |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| endothelial function | measured at a single time point when the subjects are admitted for overnight polysomnography | assess endothelial function by EndoPAT 2000 (an non-invasive device) and peripheral blood endothelial progenitor cells |
Countries
Hong Kong
Outcome results
None listed