β 1 adrenergic autoantibody on cardiomyocytes β 1 adrenergic receptor increased the occurrence of malignant arrhythmia in patients with chronic heart failure, accelerated myocardial cell damage, and participated in sudden cardiac death. Our team found for the first time that endogenous orphanin enkephalin promotes arrhythmia after acute myocardial ischemia in rats, and its mechanism includes PKC pathway, regulation of action potential duration and cell membrane surface β 1 adrenoceptor internalization disorder. At the same time, N / OFQ can regulate the level of immune factors, and immune factors participate in the formation of β1-aa. This study will be verified by clinical observation and animal experiments: first, N / OFQ, IL-6 and chronic ischemic heart failure, and β 1-aa; second, relationship between IL-6 gene 572G / C polymorphism and chronic ischemic heart failure correlation of β 1-aa production; last, objective to verify whether N / OFQ is involved in the regulation of IL-6 on chronic ischemic heart failure by knocking out N/ OFQ gene in the animal model of chronic ischemic heart failure. So as to clarify the mechanism of myocardial cell and extracellular injury, and find a new target for the treatment of chronic heart failure.

Inclusion Criteria:

• Chronic heart failure patients with reduced ejection fraction due to ischemic heart disease.

Exclusion Criteria:

• Restrictive or hypertrophic cardiomyopathy, hypertensive cardiomyopathy, acute myocarditis, acute coronary syndrome or acute myocardial infarction in the last 2 months, valvular disease (except mitral regurgitation secondary to left ventricular dilation).

During the study period, patients in the Department of Cardiology of the second hospital of Shanxi Medical University were admitted.