National Institutes of Health
Aging populations are on the rise worldwide. Aging is the major risk factor for the development of cardiac arrythmia. Age-related alterations throughout the sinoatrial node (SAN), atrioventricular node (AVN), and His of bundle (HB) and its right and left branches (RBB and LBB) cardiac conduction system (CCS) (see illustration) predispose older individuals to bradyarrhythmia, conduction disturbances, and supraventricular and ventricular tachyarrhythmias, all of which increase in incidence and prevalence with advancing age. This is known as “geriatric CCS syndrome”. Age-associated adverse remodeling of CCS is the foundation of developing this syndrome due to either an increase in susceptibility or a decrease in the pathologic threshold. Hence, the opportunity for a visual, methodological catalog of CCS is helpful for clinical and basic research in molecular, cellular, tissue, and organismal levels for diagnosis, treatment, and prevention of this syndrome in the elderly population.
In this collection, methodologies for in situ studies of nodal cell-specific events, the number of pacemaker cells, morphology, cell-cell junction, action potential and current, sinoatrial extracellular matrix and arterial remodeling as well as cardiac Purkinje fiber cellular behavior of CCS bear important implications for a complete understanding of CCS biology in young and old cardiac conditions; these techniques will provide insight into the assessment and intervention of heartbeat aging and age-related CCS geriatric syndrome.