title: An inexpensive device for determining sinus node function and the refractory periods of cardiac conduction systems.
mesh_terms: D001283:Atrioventricular Node / Q000502:physiology* / Q000503:physiopathology; D005117:Cardiac Complexes, Premature / Q000209:etiology / Q000503:physiopathology; D004558:Electric Stimulation / Q000295:instrumentation*; D004562:Electrocardiography; D006329:Heart Conduction System / Q000502:physiology*; D009431:Neural Conduction; D012032:Refractory Period, Electrophysiological; D012849:Sinoatrial Node / Q000502:physiology* / Q000503:physiopathology