Does a blockage in the heart cause a drop in Blood Pressure?

Here's an update w/question. I went for my Nuclear stress test since my regular stress test came back abnormal. Doc suspects blockages.  Had the quick squeezes in chest with the pains that shot to the elbow. They subsided after 2 days. Today during Nuclear Stress Test, my BP started out at 102/72. Usual BP is 140/80. As test progessed on the treadmill, BP went top number would gradually go up to 128 and the bottom number dropped to 59. At conclusion of test BP went to 102/60. I have been so sleepy, as if I could just fall asleep at any time and this is not like me. Any suggestions? I have a follow up appt w/doc regarding the results in 2 weeks. Thanks for any input.