Here are 7 signs that can be taken as warning and could help avert(避免) a catastrophic situation:
1.   The most common warning sign of a heart attack is the feeling of discomfort or heaviness in the chest. This feeling could also be more of a burning sensation. Any of these symptoms should not be taken lightly, and if it occurs more than once, you need to rush to your doctor. If another person is complaining of the problem, chances are they have experienced the feeling before and are only expressing it now. So, rush them to the nearest doctor or hospital immediately for a check-up.
2. Shortness of Breath
If your breathing gets heavy and the breath falls short even after a short walk, climb or other form of movement or exercise,          Even if this condition is not accompanied with chest discomfort, it should be taken as a warning sign.
3. Sweating
Whilst sweating is inevitable in the scorching(灼热的) heat of May and June, excessive sweating even in cool conditions is uncalled for.  
4. Nausea(恶心)
Regularly feeling nauseous of dizzy could imply the onset(发作) of a heart attack. Do not treat is callously(麻木不仁地) as a sign of tiredness. This could happen due to the artery(动脉) getting blocked. It could also display itself via excessive stress, fatigue after short spans of movement or exercise, or a feeling of weakness despite eating and sleeping well.
5. Numbness(麻木) in Arms
If your arms feel numb and seem to be drifting to the sides, heart problem may be the cause.
6. Unresponsiveness
If certain parts of your body begin to stop responding,         The affected parts may be the shoulders, arms or back of the neck.
7. Slurring(含糊不清) while Speaking
Difficulty while speaking need not necessarily occur after a bout of drinking with the buddies. It could be a graver situation than that! Inability to speak coherently could be the sign of a great attack. If you think you are suffering this ask a friend or relative to help by asking them to understand what you are saying.
A heart attack can be avoided if the warning signs are read correctly and in time.         They could be the result of a choked artery(动脉). Even If heart attack is not the result, a check-up should definitely not be avoided! Take care!

A．it should be a wave of happiness

B．do not ignore the circumstance.

C．Discomfort in the Chest

D．it should be a huge cause of worry.

E. do not ignore the result.
F. Seek medical aid immediately if one or more of the above symptoms are noticed.
G. If you notice such sweating, consult a medical professional immediately.