Pain is a symptom, so--for you, English Majors out there--the term asymptomatic chest pain, when referring to the absence of classical ACS pain, is an oxymoron. It is also a puzzle because it can refer to non-ischemic pain in the chest. 

Translated:

• Other things can cause chest pain besides the ACS:
  • pericarditis,
  • aortic dissection,
  • pericardial tamponade,
  • pulmonary embolism, 
  • tension pneumothorax, myocarditis, 
  • perforating peptic ulcer, and 
  • esophageal rupture (mediastinitis).
     
• There may be no chest pain at all; alternatively, there may be unusual (non-classical) manifestations of it, such as dyspnea alone, weakness, nausea and/or vomiting, epigastric pain or discomfort, palpitations, syncope, or cardiac arrest. These are more likely to present in
  • Women.
  • Diabetics.
  • Elderly. 

Thus, it describes situations without chest pain--unusual in otherwise symptomatic angina and acute coronary syndrome or 

1. other non-cardiac conditions that can mimic the ischemic symptoms of cardiac conditions.

 

Classic Chest Pain

Classic chest pain has the following characteristics:

• Vague and diffuse: cannot be pointed out with just one finger.

It is diffusely substernal or in the left chest, with possible radiation to the arm, neck, jaw, back, abdomen, or shoulders.

• Vague in its symptoms: crushing, pressure, heaviness, tightness, fullness, or squeezing.

It does not typically present as knifelike, sharp, or pleuritic. The position of the patient makes no difference.

• It comes and goes in its intensity, especially with exertion, but not with position.

Historically, "Levine's Sign" is a clutching of the fist to the chest as a gesture of chest pain associated with cardiac events. 

 

Atypical Chest Pain

There is considerable overlap between ACS chest pain and non-cardiac chest pain regarding symptomatology. The following share partially in some of the classic chest pain presentations:

• Pulmonary conditions: pulmonary embolus, pneumonia, pleuritis, asthma, and allergic reactions, among others. Distinguishable from ACS by pain increase with deep breathing or coughing.

• GI conditions: GERD (Gastroesophageal Reflux Disease), esophagitis, and other esophageal disorders. Distinguishable from ACS by onset related to meals.

• Musculoskeletal conditions are the most common cause of chest pain: costochondritis, rib fracture, etc. Distinguishable from ACS by being able to reproduce the pain with palpation or movement.

• Infectious conditions, specifically, herpes zoster. Distinguishable from ACS by the presence of a dermatome-confined painful skin eruption.

• Referred pain to the chest: from visceral sources like the gallbladder or diaphragm or spinal origins such as disc herniation.

  Psychiatric illness: a diagnosis of exclusion after taking a history and performing a physical examination, possibly involving a nitroglycerine challenge.

 

Special Populations and Atypical/Absence of Chest Pain with ACS

Atypical ACS Patients: 1/3 of MI patients represent a special population as they have no chest pain but present with dyspnea, weakness, nausea/vomiting, epigastric pain, palpitations, or syncope.

Women: may have no symptoms, and the initial presentation is discovered via an abnormal ECG done for reasons unrelated to ACS or MI. In 43% of women with MIs, chest pain is absent.

An important difference is an increased likelihood of a woman's chest pain being induced by rest, sleep, or stress (mental) instead of with exertion or in addition to it.

Diabetics: diabetics may not recognize ischemic pain, presenting with atypical angina symptoms, silent ischemia, or even silent infarction.

This may be caused by diabetic autonomic denervation of the heart.

Elderly: like women and diabetics, atypical or absent chest pain in the elderly may be their initial ACS presentation.

 

In the Field

Any chest pain--typical or atypical--should provoke a 12-lead ECG evaluation if feasible, considering the urgency. In diabetics, women, and the elderly--in the absence of chest pain--dyspnea, weakness, nausea, epigastric pain, palpitations, and syncope call for an ECG.