Anatomopathology of the normal and abnormal AV conduction system.

The specialized conduction system of the heart is responsible for both congenital and acquired disorders of cardiac rhythm. Sinoatrial disorders may result from disruption of nodal cells and takeover by subsidiary pacemaker cells. AV block may occur congenitally or result from the ravages of ischemic heart disease. Clinically overt or concealed accessory pathway conduction via various types of bypass tracts are responsible for the genesis of many supraventricular arrhythmias. Anatomohistologic correlations provide the analytic basis for many disturbances of rhythm.