Electromagnetic interference with electrocardiogram recording of exercise test equipment

Herein, we report a case of pseudosinus tachycardia resulting from an electromagnetic interference between a mobile phone and treadmill device. Electromagnetic interference from a charging mobile phone connected to the same socket with the exercise device turned the recording of a patient to that of pseudosinus tachycardia at approximately twice the rate of actual basal heart rate. Removal of the mobile phone from the socket resulted in normalization of the electrocardiogram.