A Multicenter Study on the Normal Reference Range and Clinical Significance of the Right Atrioventricular Coupling Index Assessed by Artificial Intelligence-Based Three-Dimensional Echocardiography

Healthy Adults Group Inclusion Criteria: * Participants must meet all of the following criteria to be enrolled: 1. Of Han Chinese ethnicity 2. Aged 18-79 years 3. Normal blood pressure (\< 140/90 mmHg) 4. Normal fasting blood glucose 5. Normal blood lipid levels (triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein) 6. Normal complete blood count results (hemoglobin concentration, white blood cell count, red blood cell count, platelet count) 7. Normal liver and renal function (alanine transaminase \< 2× upper limit of normal; normal creatinine and blood urea nitrogen) 8. Normal electrocardiogram results (occasional atrial premature beats may be enrolled at the investigator's discretion) 9. No structural heart disease and normal cardiac function confirmed by echocardiography Exclusion Criteria: Participants will be excluded if they meet any of the following criteria: 1. Clinically significant cardiac valve regurgitation (≥ mild severity) 2. Respiratory diseases: acute or chronic respiratory disorders 3. Endocrine diseases: thyroid disease, diabetes mellitus, hyperaldosteronism, pheochromocytoma, etc. 4. Abnormal liver function (alanine transaminase \> 2× upper limit of normal), abnormal renal function (elevated creatinine beyond normal range), or dyslipidemia (elevated triglycerides, total cholesterol, low-density lipoprotein, or high-density lipoprotein) 5. Other systemic diseases: anemia, malignancy, connective tissue disease, large artery/peripheral vascular diseases (aortic dilation, aortic dissection, coarctation of the aorta, Takayasu arteritis, atherosclerosis), etc. 6. Pregnant or lactating women 7. Professional athletes 8. Poor-quality ultrasound images that cannot support parameter measurement and analysis Pulmonary Hypertension Group Inclusion Criteria: Patients must meet all of the following criteria to be enrolled: 1. Aged 18-79 years 2. Confirmed diagnosis via right heart catheterization: mean pulmonary arterial pressure (mPAP) ≥ 20 mmHg, in accordance with the 2022 ESC/ERS guidelines Exclusion Criteria: Patients will be excluded if they meet any of the following criteria: 1. Unable to complete right heart catheterization or pressure-volume loop assessment 2. Complicated with significant left heart disease (left ventricular ejection fraction \[LVEF\] \< 50%, significant mitral valve disease) 3. Pericardial disease or arrhythmias (e.g., atrial fibrillation) that severely impair right heart function evaluation 4. Poor-quality images that prevent accurate measurement of right atrial or right ventricular parameters 5. Concurrent liver or renal disease 6. Concurrent malignancy 7. History of surgical procedures such as pulmonary endarterectomy or balloon pulmonary angioplasty Heart Failure Group Inclusion Criteria: Patients must meet all of the following criteria to be enrolled: 1. Aged 18-79 years 2. Meets the 2022 AHA/ACC/HFSA diagnostic criteria for heart failure Exclusion Criteria: Patients will be excluded if they meet any of the following criteria: 1.Complicated with significant valvular heart disease (e.g., severe mitral regurgitation, severe tricuspid regurgitation, etc.) Tricuspid Regurgitation Group Inclusion Criteria: Patients must meet all of the following criteria to be enrolled: 1. Moderate or severe primary or secondary tricuspid regurgitation confirmed by echocardiography 2. Aged 18-79 years Exclusion Criteria: Patients will be excluded if they meet any of the following criteria: 1. Pericardial disease or arrhythmias (persistent atrial fibrillation) that interfere with measurements 2. Congenital heart disease or residual lesions after surgical correction Atrial Septal Defect Group Inclusion Criteria: Patients must meet all of the following criteria to be enrolled: 1. Secundum atrial septal defect confirmed by echocardiography or transesophageal echocardiography 2. Patients who have not undergone closure or surgical correction, or stable patients with \> 3 months postoperatively 3. Aged 18-79 years Exclusion Criteria: 1.Complicated with other complex congenital heart diseases.