An Inexpensive Device for Determining Sinus Node Function and the Refractory Periods of Cardiac Conduction Systems

A simple, inexpensive device capable of measuring the refractory period of the cardiac conducting system has been described. All components used in the device may be purchased for less than $150 and commercial equipment capable of performing similar tasks costs over two-thousand dollars. The undesired features of previous methods have been eliminated and results of using the device in clinical settings have been given.