What Causes Elevated Heart Rate And Chest Discomfort?

I wish that my question is answered by Dr Sukhvinder Singh, Cardiologist who knows my case and has answered my questions in the past couple of times. Dear Dr Sukhvinder, upon my forced (medically) return from States in december, 2017 and after consulting 2-3 Cardiologists in Cbandigarh, I have finally gone for another angiography about a month back at a top corporate hospital in Mohali. This time, the SVD has blockage of between 60-70% in LAD and instead of placing a stent, the Cardiologist has taken a decision to go further as may be guided by FFR to be performed later. But I have to urgently go again to USA and I have myself requested this Cardiologist to postpone my FFR for 3-4 months. As conservative treatment is said to be one of the options, he has put me on Dilzem CD 90 mg twice a day; Nicoran 5 mg twice a day; Ecosprin Gold 20 OD besides Telma AM 40/5 mg already being taken by me. I do yoga for one hour in the morning and a walk of about 2-2.5 km daily. Though I dont feel any problem during yoga in which certain asanas require exertion, I feel some discomfort, as before, in the chest. The bigger problem, however, is that I feel higher heart rate while asleep during nights occasionally. Last night only, the heart rate was between 110-120 beats pm and it lasted for -40 minutes. I checked my BP also which read 187/87 at that time. A holter test done about 10-12 days back at GMCH didnot show anything abnormal. This morning I got my blood sugar checked after taking tea and some rusks about -40 minutes before sample being take and it reads 116. My LVEF is 55%. KINDLY ADVISE: 1) Why this discomfort at 60% SVD and when I am on these medicines? 2) what could be the cause of increased heart beat during sleep? 3) Has this level of blood sugar or any of the medicines anything to do with my problem 4) whether FFR is required at all You may kindly recall my that Stress Thallium test done at KEM Mumbai during 2014 had also shown moderate problem in this area of my heart.