The apparent arrhythmia began while the patient was undergoing CVVHD. She had no history of atrial arrhythmias. Her blood pressure and heart rate remained unchanged at 99/62 mm Hg and 70/min. There was no significant change in her clinical symptoms, physical examination findings, or repeated echocardiogram. She was diagnosed as having atrial flutter with 4:1 conduction, supported by the saw-tooth wave pattern at a rate of 300/min and narrow QRS complex. The treating clinicians initiated heparin infusion and referred the patient for cardioversion. However, careful inspection of the ECG demonstrated P waves prior to QRS complexes with different morphologies from the other flutter waves (Figure 2A). This, coupled with the fact that her heart rate did not change when she went into the “arrhythmia,” led us to suspect an artifact. The CVVHD was then paused, and the “arrhythmia” disappeared (Figure 2B). The abnormal rhythm strip returned as soon as the CVVHD resumed. Therefore, the apparent arrhythmia on both ECG and rhythm strip was an ECG artifact produced by the CVVHD.
Flutter Waves in a Dialysis Patient—Discussion. Arch Intern Med. 2011;171(18):1623-1624. doi:10.1001/archinternmed.2011.463