Right atrial electrocardiography. A bedside method for the diagnosis of cardiac arrhythmias

Although a majority of disturbances of cardiac rhythm are easily identified by inspection, auscultation, or cholinergic stimulation, routine right atrial electrocardiography has raised serious doubts as to the precise interpretation of many simple and complex mechanisms. Early workers recognized the necessity to identify atrial and ventricular activity for the diagnosis of cardiac arrhythmias and in 1906 Cremer1first used semidirect esophageal leads to record atrial potentials. However, tracings taken by esophageal leads are often technically unsatisfactory and the method is often contraindicated in seriously ill patients. The use of a saline-filled catheter for the recording of intracavitary potentials was first introduced by Hellerstein et al2in 1949. Later, this method was modified by Dreifus et al3who used a polyethylene catheter filled with 5% saline which could be introduced percutaneously. The right atrial recordings are made by connecting the patient to an ordinary electrocardiograph. Ground wires are