Objective: To develop a middle range nursing theory of impaired knowledge in individuals with heart failure.
Methods: Descriptive study of the cross type developed through the theoretical-causal validity method, which used six steps for theory building: Definition of the construction approach; Definition of theoretical-conceptual models; Definition of main concepts; Development of a pictorial scheme; Construction of propositions; and Establishment of causal relations and evidence for practice.
Results: Twenty-four articles were found, which identified two attributes, eight antecedents, and seven consequences, which gave rise to the pictogram, which schematized the concepts by relating them to cardiac physiology. Finally, 11 propositions and four causal relationships were created.
Conclusion: The constructed theory enables a targeted driving of nurses' clinical judgment regarding impaired knowledge in individuals with heart failure, culminating in individualized interventions to improve quality of life.