Chronic heart failure diagnosis: genetics
Heart failure refers to a state in which the cardiac output, no longer compensated by endogenous mechanisms, fails to meet the metabolic demands of the body. Clinically, it is defined by symptoms of breathlessness, fatigue, fluid retention, and a cardiac structural or functional abnormality. Most cases of heart failure are caused by coronary artery disease, hypertension, diabetes, and valvular heart disease, but the risk of heart failure also depends on genetic predisposition for the causative disorder as well as genetic variation that modulates the maladaptive pathophysiological response to pathophysiological stressors and the response to therapy. In a small, but almost certainly underdiagnosed proportion of cases, heart failure is caused by Mendelian genetic disorders of heart muscle (cardiomyopathies) that are mostly inherited as autosomal dominant traits characterized by locus and allelic heterogeneity and highly variable clinical expression. This chapter briefly reviews the clinical approach to the diagnosis of genetic disorders that cause heart failure and the role of genetic testing in everyday practice.