ECG-only devices rely on supjective P-wave interpretation and can easily be misinterpreted because they cannot distinguish between arterial or azygos placement.2, 3
ECG navigation devices rely on the assumption that Right Atrium depolarization always originates at the CAJ and moves in a down-left direction towards the leg.
In reality, the SA node shape and location may vary from patient to patient. This in turn may lead to variations in the RA depolarization direction and result in incorrect P-wave interpretation and imprecise catheter tip placement.
1 Data on file at VasoNova, Inc.
2 Jeon Y, et al. Transesophageal echocardiographic evaluation of ECG-guided central venous catheter placement, Canadian Journal of Anesthesia (2006) 53:10, 978-983
3 Schummer W. et al. Central venous catheters - the inability of 'intra-atrial ECG' to prove adequate positioning, British Journal of Anesthesia (2004) 93:2 193-198