A new era is emerging in the field of complex pacing as a treatment for heart failure. Cardiac resynchronization therapy (CRT) is already established as an effective therapy to improve mortality and functional capacity in patients with moderate-severe heart failure, left ventricular systolic impairment and conduction delay (prolonged QRS duration on surface ECG). Recent evidence has demonstrated that CRT is also an effective treatment for patients with mild heart failure. As the indications for CRT expand, cardiologists face the exciting prospect of exploring where pacemaker technology can help improve patient outcomes across the entire heart failure disease continuum. Enthusiasm for future application needs to be tempered with the practicalities of delivering safe and effective care within the confines of finite healthcare resources.