a panic attack的用法和样例：
- Agoraphobia is an intense fear of having a panic attack.
- Hmm. I've never thought that something positive could provoke a panic attack.
- A panic attack may last for only a few minutes or even several hours.
- Age, sex and multiplicity are three main signs to distinguish a panic attack form a heart attack.
- Three signs that indicate a person is suffering from a panic attack rather than a heart attack.