Initial diagnosis of acute coronary syndrome is almost entirely based on history, risk factors, and, to a lesser extent, ECG. The symptoms are due to myocardial ischemia, which has an underlying cause of an imbalance between supply and demand for myocardial oxygen.
* Typically, angina is a symptom of myocardial ischemia that appears in circumstances of increased oxygen demand. It usually is described as a sensation of chest pressure or heaviness that is reproduced by activities or conditions that increase myocardial oxygen demand.
* Not all patients experience chest pain. Some present with only neck, jaw, ear, arm, or epigastric discomfort.
* Other symptoms, such as shortness of breath or severe weakness, may represent anginal equivalent symptoms.
* A patient may present to the ED because of a change in pattern or severity of symptoms. A new case of angina is more difficult to diagnose because symptoms are often vague and similar to those caused by other conditions (eg, indigestion, anxiety).
* Patients may have no pain and may only complain of episodic shortness of breath, weakness, lightheadedness.
Patients may complain of the following:
* Pain, which is usually described as pressure, squeezing, or a burning sensation across the precordium and may radiate to neck, shoulder, jaw, back, upper abdomen, or either arm
* Exertional dyspnea that resolves with pain or rest
* Diaphoresis from sympathetic discharge
* Nausea from vagal stimulation
* Decreased exercise tolerance
* Patients with diabetes and elderly patients are more likely to have atypical presentations and offer only vague complaints, such as weakness, lightheadedness, and nausea.ess, diaphoresis, or nausea and vomiting
* Male gender
* Diabetes mellitus (DM)
* Smoking history
* Increased age
* Prior cerebrovascular accident (CVA) - These patients constitute 7.5% of patients with ACS and have high-risk features (Hasdai, 2003).
* Inherited metabolic disorders (Wilken, 2003)
* Methamphetamine use (Turnipseed, 2003)
* Occupational stress (Panagiotakos, 2003)
* Connective tissue disease (Soejima, 2004)
* Transient ST segment elevations (fixed changes suggest acute MI): In patients with elevated ST segments, consider LV aneurysm, pericarditis, Prinzmetal angina, early repolarization, and Wolff-Parkinson-White syndrome as possible diagnoses.
* Dynamic T-wave changes, either inversions, normalizations, or hyperacute changes: In patients with deep T-wave inversions, consider also CNS events or drug therapy with tricyclic antidepressants or phenothiazines.
* ST depressions that may be junctional, downsloping, or horizontal
* Diagnostic sensitivity may be increased by performing right-sided leads (V4R), posterior leads (V8, V9), and serial recordings