This is a diagnostic study. Patients were included from patients with clinically suspected or confirmed heart failure, and 68Ga-FAPI and 13N-NH3 gated myocardial imaging were performed to evaluate the effectiveness of 68Ga-FAPI PET imaging in visualizing the degree of myocardial fibrosis in patients with heart failure. The subjects completed 68Ga-FAPI and 13N-NH3 gated myocardial imaging in a one-stop process, and collected general information, clinical data, echocardiography, blood routine, liver and kidney function indicators, 68Ga-FAPI and 13N-NH3 PET imaging results and other imaging data of the patients and volunteers.

Fibroblast activated protein (FAP) is a type II membrane-bound glycoprotein that is highly specifically expressed in activated fibroblast reactions. The 68Ga labeled fibroblast activated protein inhibitor (68 ga-fapi) has shown advantages of high uptake and high image contrast in imaging the activated fibroblast response, including its successful use in visualizing the degree of liver fibrosis. The molecular imaging probe targeting FAP combined with the mature myocardial perfusion imaging agent 13N-NH3 can help us to achieve the following objectives: On the one hand, to investigate the myocardial fibrosis in patients with heart failure and to visualize the formation of fiBER-activated protein in the process of heart failure; At the same time, the performance of 68GA-FAPI in differential diagnosis of heart failure and grading of heart failure degree was discussed, so as to make up for the insufficiency of clinical routine imaging technology in the diagnosis of myocardial fibrosis in heart failure.

Inclusion Criteria:

• Adult patients (age 18 years or above), gender is not limited;
• Patients with clinically suspected or confirmed heart failure (supporting evidence includes visual examination, cardiac MRI, cardiac ultrasound, and serological indicators, etc.), and patients who agree to undergo 68Ga-FAPI and 13N-NH3 imaging;
• The patient or his legal representative can sign the informed consent.

Exclusion Criteria:

• Acute systemic diseases and electrolyte disorders；
• Pregnant or lactating women；
• Patients refuse to sign the informed consent.

Patients with clinically suspected or confirmed heart failure (supporting evidence including visual examination, cardiac MRI, cardiac ultrasound, and serological indicators, etc.), and who have consenting to 68GA-FAPI and 13N-NH3 imaging;