The intracavitary electrocardiogram: a routine bedside procedure elucidating obscure arrhythmias. A study in 60 patients.

: Right heart intracavitary ECG were studied in 60 patients. The procedure is performed by means of a nonmetallic saline-filled catheter introduced percutaneously. It is a simple, quick bedside method requiring minimal equipment. The intracavitary recording visualizes clear and high-voltage P waves, so that a more precise interpretation of complicated rhythm disturbances is possible. It has a distinct advantage over the esophageal lead recording in the differentiation between atrial and ventricular ectopic rhythms. The precise localization of the tip of the catheter used for central venous pressure monitoring can be determined. In 10 patients, doubtful surface ECG diagnoses were confirmed and in 10 others the original ECG interpretation was changed following intracavitary recording. In the remaining 40 patients, the method was used in order to avoid aberrant placement of the central venous pressure catheter.