Although some important progresses were made in the field of the meridian research, no breakthroughs have been achieved. Besides,there are some problems in meridian researches. Particularly, previous research of meridian phenomena involved lots of subjective elements and outcomes.Researches that use modern scientific techniques to investigate the biological characteristics of meridian phenomenon are urgently needed. Therefore, this study is designed to assess the heat transport characteristics of the Heart and Lung meridians by infrared thermal imaging (ITI). Thus, the biological characteristics of meridian phenomena could be presented objectively in a scientific methodology

This study will include 40 patients with chronic stable angina pectoris (CSAP), and 80 healthy adults. Infrared thermal imaging (ITI) examination will be adopted to assess the heat transport characteristics of the Heart and Lung meridians and investigate the specificity for the meridian-visceral correlation and site-to-site correlation between two specific meridians.

Inclusion Criteria:

Inclusion criteria for CSAP patients

• Patients should meet the diagnostic criteria of coronary heart disease, which includes the following items: 1)confirmed old myocardial infarction (MI), or a history of percutaneous coronary intervention(PCI), or coronary artery bypass grafting; 2)50% or more luminal stenosis in at least one coronary artery or major branch segment confirmed by coronary angiogram or CT angiography; 3) myocardial ischemia indicted by exercise stress radionuclide myocardial imaging; 4) treadmill exercise testing is positive (for male patients);
• Patients should meet the diagnostic criteria of CSAP and the Canadian Cardiovascular Society(CCS) classification for CSAP is level II or III;
• The medical history of CSAP is more than 3 months with attacks occurring at least twice weekly in the last month;
• 35≤age ≤75 years, male or female;
• Patients have clear consciousness and could communicate with others normally;
• Patients could understand the full study protocol and written informed consent is signed.

Inclusion criteria for healthy adults

• Healthy volunteers who could provide a recent medical examination report to confirm they have not any cardiovascular and respiratory disease;
• age≥20 years, male or female;
• Participants have clear consciousness and could communicate with others normally;
• Participants could understand the full study protocol and written consent is signed.

Exclusion Criteria:

Exclusion criteria for CSAP patients

• Patients have acute coronary syndrome and severe arrhythmias;
• Patients' chest pain is caused by valvular heart disease, hypertrophic cardiomyopathy and dilated cardiomyopathy;
• Patients' chest pain is caused by non-cardiac disease;
• Patients have concomitant lung diseases;
• Patients have serious concomitant conditions and fail to treat them effectively, such as diseases of the digestive, urinary, respiratory, hematological and nervous system;
• Patients have mental illness, severe depression, alcohol dependence or history of drug abuse;
• Pregnant or lactating patients;
• Patients are participating in other trials.

Exclusion criteria for healthy adults

• Participants have mental illness, severe depression, alcohol dependence or history of drug abuse;
• Pregnant or lactating participants ;
• Participants are participating in other trials.