ADRB1 and heart failure: The increased activation of β1-ARsignal transduction is considered to provide circulatory support during earlystages of heart failure [70, 71, 72, 73] but prolonged stimulation triggersβ1-AR desensitization in the failing heart [42, 55, 69, 74, 75, 76, 77, 78, 79, 80].Such changes due to elevated levels of circulatory catecholamines or prolongedstimulation of β1-AR system are associated with worsening cardiacoutcome, cardiac dysfunction and sudden cardiac death [41, 63, 81, 82, 83, 84, 85, 86].