Role of ion channels in heart failure and channelopathies.

Heart failure (HF) is a complication of multiple cardiac diseases and is characterized by impaired contractile and electric function. Patients with HF are not only limited by reduced contractile function but are also prone to life-threatening ventricular arrhythmias. HF itself leads to remodeling of ion channels, gap junctions, and intracellular calcium handling abnormalities that in combination with structural remodeling, e.g., fibrosis, produce a substrate for an arrhythmogenic disorders. Not only ventricular life-threatening arrhythmias contribute to increased morbidity and mortality but also atrial arrhythmias, especially atrial fibrillation (AF), are common in HF patients and contribute to morbidity and mortality. The distinct ion channel remodeling processes in HF and in channelopathies associated with HF will be discussed. Further basic research and clinical studies are needed to identify underlying molecular pathways of HF pathophysiology to provide the basis for improved patient care and individualized therapy based on individualized ion channel composition and remodeling.