An integrated catheter placement system for accurately placing a catheter within a patient's vasculature is disclosed. In one embodiment, the integrated system comprises a system console, a tip location sensor for temporary placement on the patient's chest, and an ultrasound probe. The tip location sensor senses a magnetic field of a stylet disposed in a lumen of the catheter when the catheter is disposed in the vasculature. The ultrasound probe ultrasonically images a portion of the vasculature prior to introduction of the catheter. ECG signal-based catheter tip guidance is included in the integrated system to enable guidance of the catheter tip to a desired position with respect to a node of the patient's heart. Various aspects for visualizing and manipulating display of the ECG signal data acquired via the present system, together with aspects of various ECG sensor configurations, are also disclosed.