Why did my BP never return to pre-treadmill number 120/70?

[Maxcran]

I had an ECG and Echocardiogram. I'm 61, 129lbs, used to be athletic, retired now, more sedentary, felt winded on the treadmill but finished...highest BP was 155/75 or 80. My BP would not recover to base line. Even after 10-15 minutes it was still 135/70....before the test started it was 120/70. The tech kept taking BP but finally I had to go without it ever returning to homeostasis....what does it mean when it's not recovering in a normal time frame?

[Ger57]

What is in your opinion a normal time frame?
If you do the treadmill test till maximum effort, I think it is quite normal that your body has not yet returned to its resting situation in 10-15 minutes. So, your heart rate as well as respiration rate and BP will still be a bit elevated.