[Intra-atrial ECG via a central venous catheter]

The authors registered measurements of ECG via the saline column in a central venous catheter in a prospective investigation. The P-waves in the atrial ECG from various heights in the atrium and low down in the superior vena cava were compared with lead II in surface ECG and this revealed significantly larger P-waves in the invasive ECG. In patients with tachyarrhythmia, who have or require a central venous catheter, the atrial ECG will thus present an alternative to the oesophageal ECG in the diagnostic elucidation. The method is found to be easy to carry out and it is without risks or discomfort for the patient and it provides good information about atrial activity.