Graphical Abstract.

Upper panel: Schematic representation of the interaction between the various arrhythmia and conduction abnormalities with four electrical abnormalities and their consequences for remodelling and developing heart failure. Red text in boxes indicates the therapeutic approaches that treat the electrical abnormalities and thereby also heart failure. CRT, cardiac resynchronization therapy. Lower panel: Flow chart of recommended checks for the eligibility of heart failure with reduced ejection fraction patients for the various electrical therapies based on the evidence presented in the upper panel and guidelines.