In patients with heart failure (HF), it is well known that arrhythmias confer a substantial risk of mortality and morbidity, and this represents a major healthcare burden in Japan. Currently, HF hospitalizations are increasing, and they are related to cardiac arrhythmias in most cases. Indeed, cardiologist often experience that episodes of decompensation is caused by tachyarrhythmias, such as atrial fibrillation (AF). HF and AF are the most common underlying cardiac disorders in patients presenting with stroke. AF per se may contribute to an increased risk of mortality and morbidity from ischemic stroke and may aggravate the signs and symptoms of HF. Sudden cardiac death is also a major cause of mortality among HF patients and is generally related to ventricular arrhythmias (VAs). Pharmacotherapies with various actions, cardiac resynchronization therapy (CRT), other implantable devices, and developments in cardiac monitoring have been introduced for management of HF and arrhythmias in clinical practice. These allow us improvements and better management of VAs in HF, particularly in patients with reduced LVEF (HF-rEF). In HF patients with preserved LVEF (HF-pEF), persistent cardiac arrhythmia with uncontrolled ventricular rate may result in left ventricular dilatation and systolic dysfunction with signs and symptoms of HF, namely tachycardia-induced cardiomyopathy. With effective treatment of the culprit arrhythmia, the condition is reversible, depending on the presence or absence of other structural heart disease. After successful catheter ablation of the substrate of the spontaneous arrhythmias, a significant improvement in ventricular function may has been achieved. In this session, we would like to discuss widely regarding management strategies for patients with HF and arrhythmias using novel/alternative pharmacotherapies or implantable cardiac devices.