Comparison of the amplitude of the P-wave from intracardiac electrocardiogram obtained by means of a central venous catheter filled with saline solution to that obtained via esophageal electrocardiogram.

Recognition of the P wave is important for the correct characterization of atrial and ventricular arrhythmias. When the P wave is difficult to identify on standard electrocardiography (SECG), either esophageal electrocardiography (EECG) or intracardiac electrocardiography (IC-ECG), central venous catheter may be used. The feasibility of these methods has already been demonstrated, but there is no published study comparing them. This study compared the amplitude of the P wave obtained by IC-ECG with those of the P waves obtained by EECG and SECG. SECG, EECG, and IC-ECG were performed on each patient. IC-ECG and EECG made it possible to register P waves larger than registered by SECG (p <0.00001). The difference between the largest P waves obtained with IC-ECG (5.93 +/- 3.56 mm) and EECG (4.67 +/- 2.16 mm) was not statistically significant (p = 0.1953). In conclusion, IC-ECG is easy to perform and magnifies the P wave at least as effectively as EECG.