Negative effect of Imdur?

Four years ago I had stents placed to open my LAD and the circumflex artery.  The (untreated) anterior artery is 100% blocked, but its portion of my heart seems to be functioning pretty well from collateral supply.  I play 3-4 sessions of tennis a week and three 45 min sessions on treadmill, interspersed with floor exercises and hand weights.  My cardiologist is very against tennis (I play mainly doubles).  He had suggested I take a nitro immediately before each tennis session.  I have no chest pain, but understood that the nitro might help avoid some sort of cardiac incident.  Now he has prescribed a daily 30 mg of Imdur (slow release nitro).    I also had an abdominal aortic aneurysm repaired about 2.5 years ago and it left me with an inadequate supply to one leg.  After 15 min on the treadmill, or a vigorous set of tennis, the leg/hip/buttock area have a lot of pain and I get to the point where I can barely walk.  2-5 min rest and I am good as new, meaning to me (and the vascular surgeon) that the problem is indeed inadequate flow through the repair (which they do not want to mess with further).  Which leads to my question.  This blood-flow condition is much worse after taking the Imdur.  I had thought it might actually relieve the condition somewhat, by allowing increased flow through the dilated vessels.  But the opposite seems to be the case.   Anyone understand this?  Or am I hallucinating?

[kenkeith]

Imdur is a nitrate that targets coronary vessels.  It relaxes and dilates the coronary arteries to supply an ample amount of blood/oxygen.  The cost may be a deficit in other areas when there is vigorous exertion.  There is other medication to dilate system vessels such as an ACE inhibitor and a beta blocker.

I have a totally blocked LAD and the RCA was stented about 4 years ago. I was taking a nitrate daily, but now I take Isosorbide (generic nitrate) when there is an expectation of angina (tightness in chest area) and that is usually 3X a week on the treadmill for a half an hour (4mph [7 METs]) and weight resistance training.  Sometimes I have been able to do the exercise without Isosorbide, and sometimes I take nitro if angina begins to occur.  It works for me, but your situation involves different conditions and circumstances.