What is happening?

i am a 63 year female with dilated cardiomyopathy (10 Yrs), an implanted defibbrilator (8 yrs), a stent inserted this winter for a blockage in my pelvic area and recently been diagnosed with severe emphysema.  I am to use oxygen upon exertion and while sleeping.  yesterday while sitting and watching television i had a very painful tightness in my chest area....even my bra fastened was making the tightness feel tighter.... the pain went down the inside of my right arm.  i immediately started receiving the oxygen and after approximately 5 minutes the pain went away.  

today i phoned the cardiologists office and spoke with a nurse.  she infomed me that beings i feel fine today, not to worry about it because my heart cath did not show any blockage - but this was done 10 years ago.  I am already on plavix due to the blockage in the winter this year.  i do not understand if this is the beginnings of having heart attacks - which there is a history of in my family - or why the nurses did not seemed concerned.  this is the first time in 10 yrs that i have phoned them with a problem like this.  should i be concerned?

[CCF HeartMD6]

Any chest discomfort that is accompanied by symptoms such as shortness of breath, nausea, vomiting, arm/jaw pain, or sweating should always be evaluated further by a licensed physician. Given your multiple medical problems (most notably your heart and lungs), the causes for your symptoms can be due to a number of things. Unfortunately, it is impossible to say for certain what is going on over the internet -- and without a complete history and physical examination. I agree that just because your heart catheterization was normal 10 years ago does not mean that could still be the case today -- and that all of your symptoms should be investigated further.