Relationships between the changes of P-wave form of intracavitary electrocardiogram and the tip position of valved peripherally inserted central catheter

Objective To explore the changing rule of the P-wave form of intracavitary electrocardiogram during the procedure of valved peripherally inserted central catheter intubation(PICC). Methods A total of 21 patients received chemotherapy in Drum Tower Hospital from February 2015 to March 2015 were enrolled in the study.Saline technique was used to help getting a good intracavitary electrocardiogram(IEGM) trace during valved PICC intubation.Surface(A)electrocardiograms of the patients were recorded before valved PICC intubation.During valved PICC intubation, the IEGMs were recorded when the tips of catheters were in different positions.The amplitudes and slopes of P-wave of different positions were compared with each other. Results Valved PICCs were inserted successfully in all the patients.The maximum average value of amplitude[(9.65±2.09) mm]and slope(6.38±2.27)of P-wave were recorded in the upper third of right atrium(RA). There were no statistically significant differences between the value of amplitude, slope of upper third and middle third of RA(P=0.36, P=0, 26). The method of using slope of P-wave to judge whether the tip was in the upper third of RA had no statistical difference with the method of using amplitude of P-wave[13(61.9%)vs.16(76.2%), P=0.32]. There were three types of P-wave form from IEGMs when the tips entered into the upper of RA from super vena cava(SVC)RA junction. Conclusions The typical changes of P-wave form can help operators to place the tip of valved PICC in the right position. Key words: Intracavitary electrocardiogram; Peripherally inserted cental catheters; P-wave form