Acute Coronary Syndrome Clinical Presentation

Updated: Sep 30, 2020
  • Author: David L Coven, MD, PhD; Chief Editor: Eric H Yang, MD  more...
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The severity and duration of coronary artery obstruction, the volume of myocardium affected, the level of demand, and the ability of the rest of the heart to compensate are major determinants of a patient's clinical presentation and outcome. A patient may present to the ED because of a change in pattern or severity of symptoms.

Typically, angina is a symptom of myocardial ischemia that appears in circumstances of increased oxygen demand. It is usually described as a sensation of chest pressure or heaviness that is reproduced by activities or conditions that increase myocardial oxygen demand. 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).

However, not all patients experience chest pain. They may present with only neck, jaw, ear, arm, or epigastric discomfort. Some patients, including some who are elderly or who have diabetes, present with no pain, complaining only of episodic shortness of breath, severe weakness, light-headedness, diaphoresis, or nausea and vomiting. Elderly persons may also present only with altered mental status. Those with preexisting altered mental status or dementia may have no recollection of recent symptoms and may have no complaints.

In addition, evidence exists that women more often have coronary events without typical symptoms, which may explain the frequent failure of clinicians to initially diagnose ACS in women.

A summary of patient complaints is as follows:

  • Palpitations

  • 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 either arm

  • Exertional dyspnea that resolves with pain or rest

  • Diaphoresis from sympathetic discharge

  • Nausea from vagal stimulation

  • Decreased exercise tolerance

Stable angina involves episodic pain lasting 5-15 minutes, is provoked by exertion, and is relieved by rest or nitroglycerin. In unstable angina, patients have increased risk for adverse cardiac events, such as myocardial infarction or death. New-onset exertional angina can occur at rest and is of increasing frequency or duration or is refractory to nitroglycerin. Variant angina (Prinzmetal angina) occurs primarily at rest, is triggered by smoking, and is thought to be due to coronary vasospasm.


Physical Examination

Physical examination results are frequently normal. If chest pain is ongoing, the patient will usually lie quietly in bed and may appear anxious, diaphoretic, and pale. Physical findings can vary from normal to any of the following:

  • Hypotension - Indicates ventricular dysfunction due to myocardial ischemia, infarction, or acute valvular dysfunction

  • Hypertension - May precipitate angina or reflect elevated catecholamine levels due to anxiety or to exogenous sympathomimetic stimulation

  • Diaphoresis

  • Pulmonary edema and other signs of left heart failure

  • Extracardiac vascular disease

  • Jugular venous distention

  • Cool, clammy skin and diaphoresis in patients with cardiogenic shock

In addition, a third heart sound (S3) may be present, and frequently, a fourth heart sound (S4) exists. The latter is especially prevalent in patients with inferior-wall ischemia and may be heard in patients with ischemia or systolic murmur secondary to mitral regurgitation

A systolic murmur related to dynamic obstruction of the left ventricular (LV) outflow tract may also occur. It is caused by hyperdynamic motion of the basal left ventricular myocardium and may be heard in patients with an apical infarct.

A new murmur may reflect papillary muscle dysfunction. Rales on pulmonary examination may suggest LV dysfunction or mitral regurgitation.

Patients who present to the ED with chest pain who have a low short-term risk of a major adverse cardiac event must be identified to facilitate early discharge in order to avoid lengthy and costly hospital stays. [14] The ASPECT study tested a 2-hour, accelerated diagnostic protocol (ADP) that included the use of a structured pretest probability scoring method, electrocardiography, and a point-of-care biomarker panel that included troponin, creatine kinase MB, and myoglobin levels. The study suggests that ADP can identify patients at low risk for a short-term major adverse cardiac event who may be suitable for early discharge; such an approach could be used to decrease the overall observation periods and admissions for chest pain and has the potential to affect health-service delivery worldwide.


ACP Screening Guidelines for CHD

In 2015, the American College of Physicians (ACP) released guidelines on screening for coronary heart disease (CHD), including the following [15] :

  • There is no evidence that cardiac screening improves patient outcomes in asymptomatic, low-risk adults.

  • Potential harms of cardiac screening include false-positive results causing patients to undergo potentially unnecessary tests and procedures.

  • Among adults at low risk, prevalence of coronary heart disease is low, and cardiac screening is of low predictive value. Therefore, cardiac screening is of low yield, and the probability that positive findings will influence therapeutic decision making is low.

  • Clinicians should therefore emphasize strategies to reduce cardiovascular risk even further among low-risk adults by treating modifiable risk factors (smoking, diabetes, blood pressure, hyperlipidemia, overweight, and exercise).

  • Clinicians should not screen asymptomatic, low-risk adults for cardiac disease using resting or stress electrocardiography, stress echocardiography, or stress myocardial perfusion imaging.

  • Clinicians should conduct cardiovascular risk assessment with a global risk score combining individual risk factor measurements into a single quantitative estimate of risk.

  • The ACP recommendations do not apply to symptomatic patients or to screening athletes before participation in various events.