Patient may feel sensation of chest pressure or heaviness, which is reproduced by activities or conditions that increase myocardial oxygen demand.
* Not all patients experience chest discomfort. Some present with only neck, jaw, ear, arm, or epigastric discomfort.
* Other symptoms, such as shortness of breath breathlessness or severe weakness, may represent anginal equivalents.
* A patient may present to the Emergency department because of a change in pattern or severity of symptoms.
* Other associated features are weakness, lightheadedness, diaphoresis, or nausea and vomiting.
* Patients may complain of the following:
*
o Palpitations tachycardia or bradycardia
o Pain, which is usually described as pressure, squeezing, or a burning sensation across the precordium and may radiate to the neck, shoulder, jaw, back, upper abdomen, or arms
o Exertional dyspnea breathlessness that resolves with pain or rest
o Diaphoresis (increased perspiration) from sympathetic discharge
o Nausea from vagal stimulation
o Decreased exercise tolerance
o Patients with diabetes and elderly patients are more likely to have atypical presentations and offer only vague complaints, such as weakness, dyspnea, lightheadedness, and nausea.

Stable angina
o Involves episodic pain lasting 5-15 minutes
o Provoked by exertion
o Relieved by rest or nitroglycerin

Unstable angina:
Patients have increased risk for adverse cardiac events, such as MI or death. Three clinically distinct forms exist, as follows:
o New-onset exertional angina
o Angina of increasing frequency or duration or refractory to nitroglycerin
o Angina at rest

* Variant angina (Prinzmetal angina)
o Occurs primarily at rest
o Triggered by smoking
o Thought to be due to coronary vasospasm

* Elderly persons and those with diabetes may have particularly subtle presentations and may complain of fatigue, syncope, or weakness. Elderly persons may also present with only altered mental status. Those with preexisting altered mental status or dementia may have no recollection of recent symptoms and may have no complaints whatsoever.

* As many as half of cases of ACS are clinically silent in that they do not cause the classic symptoms described above and consequently go unrecognized by the patient. Maintain a high index of suspicion for ACS especially when evaluating women, patients with diabetes, older patients, patients with dementia, and those with a history of heart failure patients.