Heart rate difference between Venu and chest monitor.

While doing a stress-echo at my cardiologist’s office, my pulse went above 150 and stayed there. I thought that this was a good opportunity to compare to my Venu. I was surprised to see that my Venu was saying 62, and the gear I was connected to saying 150. Following that I bought a new chest monitor. Today, I had it happen again. The HRM was over 150, and the Venu around 60. 

i have the Venu fitted properly so am left wondering if I am seeing the difference between wrist and chest. I also wonder if all wrist devices are the same.