Signs or symtoms of impending myocardial infarction?

Sign and symptoms vary from patients, all the above respondents are correct.
It may be symptomless too at times.
The common signs weather history of Diabetes and Hypertension is present or not are as follows, one or two symptoms are usually present:
Chest pain or epigastric pain.
Radiation of pain from chest to left arm, back, jaw.
Nausea / Vomiting.
Dizziness/ Vertigo.
Fast thready pulse; it can be slow as well.
Profuse or Mild Sweating.
Shortness of breath.
Cold clammy skin.
The above are typical signs and symptoms, which require immediate cardiac emergency procedure/s.
This is further confirmed by EKG, and cardiac enzymes, anyway you have to start the ACS protocol.

www.webmd.com can provide you with all the symptoms

I'm not medically qualified, but am writing from experience, as my husband sadly died of this in 1991. The symptoms are a grey pallour, intermittent dizziness, cold sweats, and shortness of breath. He also tired very easily, and the most menial tasks were an enormous effort for him.

My husband was also a diabetic, and apparently it is more common in diabetics than in non-diabetics.

Very high blood pressure.
http://www.mayoclinic.com/health/heart-a...

As someone who works for 10 cardiologists, I have to say EVERYONE is different.
Some signs:
dull OR sharp pain in chest
numbness and tingling in left arm
back or neck pain
headache
sweating
etc...
Some people have all plus some and others don't have any.
If you think you are having a heart attack, GO TO THE E.R.
Some people have them, and then the pain goes away, so they don't go to the DR or hospital. BAD IDEA! Some people have mild ones until the BIG ONE hits. You can have a routine test, EKG, where they will put electrodes (stickers) on your chest for less than 3minutes. No pain inflicted unless you have a hairy chest when they rip off the stickers (my favorite part when it comes to mean patients with attitudes) This will help them read the electrical impulses your heart is giving off along with showing your rhythm and rate. It can determine if there might be a problem. If they suspect something or need to rule out heart damage, they will do further tests like an echo cardiogram (ultrasound of your heart) and/or stress test (walk on a treadmill and take pictures of your heart). Needless to say, if you wait, whether you are or aren't having one, YOUR LIFE MAY DEPEND ON IT! Go to the E.R.

From my heart to yours..........................

There are symptoms of AMI that typically occur in men, symptoms that typically occur in women and there is the silent MI, which is atypical in its presentation.

Typical Male Symptoms: Feelings of heaviness or tightness that progresses to severe gripping pain in the lower sternum. Pain that radiates down the left arm. The pain isn't relieved by rest or nytroglycerin. Then shortness of breath, sweating, anxiety.

Typical Female Symptoms: More likely to have upper abdominal pain, dyspnea, nausea and fatigue as well as chest pain. There may be shoulder or upper back pain.

Both Male & Female: Nausea and vomiting. Pulse becomes rapid and weak (thready). Blood pressure drops. Skin pallor and cyanosis.