His bundle studies
The bundle of his is a group of electrical fibres in the heart that are responsible for transmitting the electrical impulses which generate a normal cardiac contraction. This test may be performed in cases of cardiac arrhythmias, to locate a specific area responsible for a conduction defect and to determine the need for cardiac pacemaker placement.
The test involves the passage of a an electrode tipped catheter into the heart. This catheter is usually threaded through a neck, arm or chest vein. Measurements of the his bundle can then be performed while standard ecg leads are placed on the arms and legs.