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

Oesophageal electrocardiography in healthy horses

“…One of the aims of this study was to obtain a relatively larger P wave on oesophageal ECG recordings, as described in human medicine [6,12]. The study demonstrated that oesophageal ECG is effective in magnifying the P wave amplitude.…”

“…In human medicine, the value of oesophageal ECG recording in the identification of atrial activity and diagnosis of arrhythmias has been recognised for many years [5,6]. Due to the proximity of the left atrium to the oesophagus, P waves are magnified, which facilitates P wave identification.…”

Electrocardiography-guided and retrospective analysis of central venous catheter placement in the dog

“…The fundamental concept behind intra-cardiac ECG is that a guide wire/catheter inserted inside the vena cava can be used as an electrode and its position correlated to the amplitude of the p-wave. This principle is based on the proximity theory which states that the closer the electrode is to the area in which the myocardial electrical impulse is generated the greater the registered voltage on the ECG (Benzadón et al 2006). Schummer et al (2004b) attempted to explain this phenomenon by relating it to the far and near field effects of electromagnetic fields.…”

High-resolution esophageal long-term ECG allows detailed atrial wave morphology analysis in case of atrial ectopic beats

“…In contrast to the sECG, the esophageal ECG (eECG) features high atrial signal amplitude [2]. The collapsed esophagus exerts continuous pressure on the esophageal electrode and the esophageal mucosa incessantly produces an electrolyte-like mucus.…”