[Intracavitary electrocardiography. A useful method for checking the correct localization of central venous...

A placement technique for central venous catheters (CVC) using the intracavitary electrocardiography (ICECG) as well as three different connection systems of the CVC to the electrocardiographic monitor are described. The aim of the present study was to evaluate the correct placement of the CVC by this technique with posterior radiologic confirmation being carried out. The study was undertaken in 30 patients connecting a CVC to a negative electrode of the standard lead II and the positive to the left leg. The CVC was advanced and the changes in the morphology of the "P" wave as it passed along the superior vena cava (SVC) to the right auricle (RA) were observed. In 28 of the 30 patients (93.3%) a biphasic "P" wave (right auricle) was achieved with the CVC being thereafter withdrawn until the SVC (this location was radiologically confirmed posteriorly). In 2 patients (6.6%) a biphasic "P" wave was not obtained and an abnormal position of the CVC was radiologically demonstrated at surgery (one in the ipsilateral subclavian vein and the other had a ring within the right subclavian vein impeding progression). The mean time used in the performance of this technique was 220 +/- 40 s. It is concluded that intracavitary electrocardiography is a simple, easy to learn and perform technique which does not delay surgical procedure and it is a reliable method for placing the end of the CVC.