Key Feature 4a: Given an appropriate history of chest pain suggestive of herpes zoster infection, hiatal hernia, reflux, esophageal spasm, infections, or peptic ulcer disease: Propose the diagnosis.
Skill: Clinical Reasoning
Phase: Diagnosis

Key Feature 4b: Given an appropriate history of chest pain suggestive of herpes zoster infection, hiatal hernia, reflux, esophageal spasm, infections, or peptic ulcer disease: Do an appropriate work-up/follow-up to confirm the suspected diagnosis.
Skill: Clinical Reasoning
Phase: Investigation

If a patient presents with chest pain and you have considered and either ruled out or otherwise have a very low pretest probability for the 6 acutely life-threatening etiologies of the chest pain, it is then time to consider stable ischemic heart disease and the vast differential possibilities with a more detailed history and physical examination. (If not, and the patient is presenting to you in an outpatient clinic, they need an emergent referral to the nearest ED.) The illness scripts and associated work-ups/follow-ups (to ensure resolution as expected) for some of the common not acutely life-threatening and nonischemic etiologies and of chest pain are as follows (per UpToDate), with examples provided from various body systems that may be responsible.

Pericarditis (Nonischemic cardiac chest pain)

• Pericarditis refers to inflammation of the pericardial sac. 
• The diagnosis of pericarditis requires the presence of at least 2 of the following 4 criteria: 

1. Typical chest pain (sharp and pleuritic, improved by sitting up and leaning forward)
2. Pericardial friction rub
3. Suggestive ECG changes (typically widespread ST segment elevation)
4. New or worsening pericardial effusion (via echocardiogram)

• In developed countries, unless there is an apparent medical or surgical condition known to be associated with pericarditis, most cases of acute pericarditis in immunocompetent patients are due to viral infection or are idiopathic. Acute viral or idiopathic pericarditis typically follows a brief and benign course after empiric treatment with anti-inflammatory drugs.

Pneumonia (Respiratory system)

• Patients with pneumonia may have chest pain, which is often pleuritic. They also have fever and productive cough, and they may be hypoxemic.
• Chest xray is the standard diagnostic tool
• Treatment is with antimicrobials tailored to the suspected etiology

Esophageal or Peptic Ulcer Disease (Gastrointestinal system)

• Patients with suspected gastrointestinal etiologies often complain of heartburn, regurgitation, pain associated with food, and indigestion. However, some patients may also complain of anginal symptoms. 
• Patients with a negative cardiac evaluation and anginal-like chest pain often have gastroesophageal reflux disease (GERD). GERD can be diagnosed based on symptoms and response to therapy, with initial therapy depending on the severity of symptoms. 
• Patients with alarm features should undergo an early upper endoscopy, preferably within two weeks. Patients with alarm features in whom the early upper endoscopy is negative are subsequently managed similarly to patients without alarm features.
  • Alarm features: (DR GI OW)
    1. Dysphagia
    2. Recurrent vomiting
    3. Gastrointestinal bleeding
    4. Iron deficiency anemia
    5. Odynophagia
    6. Weight loss
• Patients without alarm features should be treated with an empiric trial of PPIs for eight weeks. Further evaluation with both esophageal impedance and pH monitoring and esophageal manometry should be pursued in these patients if they fail to respond to PPIs. In the absence of alarm features, we reserve upper endoscopy for patients in whom impedance/pH and manometry testing are unrevealing.
• Patients with an esophageal motility disorder (aka esophageal spasm) may have retrosternal chest pain that patients may often describe as squeezing retrosternal pain or spasm. Patients with an esophageal motility disorder usually present with dysphagia for solids and liquids. Patients have esophageal dysphagia characterized by difficulty swallowing several seconds after initiating a swallow and a sensation of food getting stuck in the esophagus. In some cases, patients have symptoms of heartburn or regurgitation. 
• Hiatus hernia is not a diagnosis that is pursued in and of itself and is usually discovered incidentally on upper endoscopy, manometry, or imaging performed to exclude other diagnoses. Repair of an isolated, asymptomatic sliding hiatus hernia is not indicated. Management of patients with a symptomatic sliding hiatus hernia consists of management of GERD.
• The diagnosis of peptic ulcer disease is definitively established by direct visualization of the ulcer on upper endoscopy. All patients diagnosed with peptic ulcer disease should undergo testing for H. pylori infection. Additional evaluation to determine the underlying etiology should be considered when H. pylori and NSAID use have been excluded. 
• Patients with H. pylori should be treated with a goal of eradication of H. pylori infection. In patients treated for H. pylori, eradication of infection should be confirmed four or more weeks after the completion of eradication therapy.
• All patients with peptic ulcer disease should receive antisecretory therapy to facilitate ulcer healing. 
• Patients with duodenal ulcers who have been treated do not need further endoscopy unless symptoms persist or recur. The decision to perform surveillance endoscopy in patients with a gastric ulcer should be individualized.

Herpes Zoster Infection

• Chest pain may be the presenting symptom of herpes zoster, preceding the characteristic rash. Dysesthesia is usually present in the affected dermatome. Postherpetic neuralgia may also cause chest pain.
• Antiviral therapy is recommended for patients with uncomplicated herpes zoster who present within 72 hours of clinical symptoms. For patients who present after 72 hours, antiviral therapy is recommended if new lesions are appearing at the time of presentation. There is likely minimal benefit of antiviral therapy in the patient who has lesions that have encrusted.

Chest Pain

Key Feature 3: In a patient with unexplained chest pain, rule out ischemic heart disease.
​Skill: Clinical Reasoning, Selectivity
Phase: Hypothesis generation, Investigation

Ischemic Heart Disease

Key Feature 3: In a patient presenting with symptoms suggestive of ischemic heart disease but in whom the diagnosis may not be obvious, do not eliminate the diagnosis solely because of tests with limited specificity and sensitivity (ex: electrocardiography, exercise stress testing, normal enzyme results).
Skill: Selectivity, Clinical Reasoning
Phase: Diagnosis, Investigation

Key Feature 6: In a person with diagnosed acute coronary syndrome (ex: cardiogenic shock, arrhythmia, pulmonary edema, acute myocardial infarction, unstable angina), manage the condition in an appropriate and timely manner.
Skill: Selectivity
Phase: Treatment

In the patient who presents to clinic with a history of chest pain, the features listed below should raise your suspicion that the pain is secondary to cardiac ischemia, per UpToDate:

• Angina is usually characterized more as a discomfort (pressure, squeezing, constriction, choking, burning, tightness, knot in throat or chest) rather than pain (sharp, stabbing, pins and needles-like).
• Angina is typically gradual in onset and offset. Once present, it is constant and does not change with position or respiration.
• Angina is not felt in a specific spot, but is usually a diffuse discomfort that may be difficult to localize.
• Angina is usually elicited by activities and situations that increase myocardial oxygen demand.
• Angina generally lasts for two to five minutes.
• Angina is often associated with other symptoms; the most common are shortness of breath, nausea, and diaphoresis.

However well the episode(s) of chest pain fit the above descriptors, this can help you determine your pretest probability of the chest pain being secondary to cardiac ischemia. The following table suggests a way of categorizing pretest probability:

If you are concerned for active cardiac ischemia and a possible myocardial infarction (MI) then you need to send any patient who comes into your outpatient office to the emergency for the appropriate  workup and treatment (see last post). In the patient who presents without ongoing ischemic chest pain but in whom you suspect they may have ischemic heart disease, the next step is generally to get a baseline ECG and then refer them for cardiac stress testing. If the initial workup, either in the acute or stable patient, is negative for ischemic heart disease, be it via ECG, cardiac biomarkers, or stress testing, remember that the tests can be falsely negative. If you are still suspicious for ischemic heart disease, consider further testing with repeat ECG, repeat cardiac biomarkers, and/or coronary angiography. See the algorithm and table below for investigation and workup of suspected acute coronary syndrome. The institution at which you are working may also have a protocol for acute chest pain and suspected ACS. Consider using a Grace or TIMI score (on your medical calculator app) for risk stratification. If you think a patient may be having complications of acute coronary syndrome, see these past blog posts for management of an arrhythmia or cardiogenic shock. 

See this Life in the Fast Lane post about left bundle branch blocks.

Chest Pain

Key Feature 1: Given a patient with undefined chest pain, take an adequate history to make a specific diagnosis (ex: determine risk factors, whether the pain is pleuritic or sharp, pressure, etc.).
Skill: Clinical Reasoning
Phase: History

Key Feature 2: Given a clinical scenario suggestive of life-threatening conditions (ex: pulmonary embolism, tamponade, dissection, pneumothorax), begin timely treatment (before the diagnosis is confirmed, while doing an appropriate work-up).
Skill: Selectivity
Phase: Diagnosis, Treatment

Key Feature 5a: Given a suspected diagnosis of pulmonary embolism: Do not rule out the diagnosis solely on the basis of a test with low sensitivity and specificity.
Skill: Clinical Reasoning 
Phase: Hypothesis generation, Diagnosis

Key Feature 5b: Given a suspected diagnosis of pulmonary embolism: Begin appropriate treatment immediately.
Skill: Selectivity
Phase: Treatment

Ischemic Heart Disease

Key Feature 1: Given a specific clinical scenario in the office or emergency setting, diagnose presentations of ischemic heart disease (IHD) that are:

1. Classic
2. Atypical (ex: in women, those with diabetes, the young, those at no risk)

Skill: Clinical Reasoning, Selectivity
Phase: Hypothesis generation, Diagnosis

When a patient presents with chest pain, first consider the ABCs. If the patient appears stable, the priority is then to risk stratify the likelihood of a life-threatening etiology of the chest pain, which are as follows:

1. ​Acute coronary syndrome (ACS)
2. Acute aortic dissection
3. Pulmonary embolism
4. Tension pneumothorax
5. Pericardial tamponade
6. Esophageal rupture

If you have obtain any information via history or physical exam that raises your suspicion for any of the above, it is critical to take steps immediately to further investigate +/- intervene immediately. Information that should raise your suspicion for the above etiologies includes:

1. ACS: Symptoms associated with the highest relative risk of myocardial infarction (MI) include radiation to an upper extremity, particularly when there is radiation to both arms, and pain associated with diaphoresis or with nausea and vomiting. Immediate investigations and intervention include obtaining a 12-lead ECG, attaching a cardiac monitor, obtaining IV access and  obtaining bloodwork including a troponin level, supplemental oxygen if indicated, and giving ASA 325 mg chewed +/- sublingual or intravenous nitroglycerin (contraindicated if systolic blood pressure <90 mmHg or ≥30 mmHg below baseline, marked bradycardia or tachycardia, known or suspected right ventricular infarction, phosphodiesterase inhibitor use within the last 24 to 48 hours, hypertrophic cardiomyopathy, or severe aortic stenosis).
2. Acute aortic dissection: Acute aortic dissection typically presents with an abrupt onset of thoracic or abdominal pain with a sharp, tearing, and/or ripping character, with or without syncope, symptoms of stroke, heart failure, or other clinical signs of end-organ ischemia (splanchnic ischemia, renal insufficiency, extremity ischemia, spinal cord ischemia). Physical examination may reveal a pulse or blood pressure discrepancy. If suspicious of a dissection, obtain a CT chest (beside ultrasound instead if the patient is unstable).
3. Pulmonary embolism (PE): The most common presenting symptom is dyspnea followed by chest pain and cough. Well's Criteria can hep risk stratify. Obtain a CTPA (computed tomography pulmonary angiography) if the patient is high risk. The mainstay of therapy for patients with confirmed PE is anticoagulation, depending upon the risk of bleeding (consider calculating HAS-BLED score). Alternative treatments include thrombolysis, inferior vena cava filters, and embolectomy.
4. Tension pneumothorax: Suspect a tension pneumothorax in the patient with hypotension, dyspnea, and ipsilateral decreased breath sounds. If suspected, obtain a chest xray. Immediate intervention with needle thoracocentesis is indicated if there is a high degree of clinical suspicion, even prior to obtaining confirmatory imaging.
5. Pericardial tamponade: Patients with acute cardiac tamponade typically have chest pain, dyspnea, and/or tachypnea associated with trauma or a cardiac procedure. Findings on physical examination may include sinus tachycardia, elevated jugular venous pressure, hypotension, and an exaggerated inspiratory decrease in systolic blood pressure (pulsus paradoxus). Bedside ultrasound is useful for both the diagnosis and treatment with pericardiocentesis. 
6. Esophageal rupture: This diagnosis should be suspected in patients with severe chest, neck, or upper abdominal pain after an episode of severe retching and vomiting or other causes of increased intrathoracic pressure and the presence of subcutaneous emphysema (crepitus) on physical exam. If there is a high index of suspicion, obtain a CT scan.

Otherwise the differential diagnosis for chest pain is broad, and includes multiple cardiac, pulmonary, gastrointestinal, musculoskeletal, psychiatric, and other causes. It is important to take a thorough history and perform a thorough physical examination of the relevant systems to narrow down the list of most likely possibilities to perform an appropriate workup. 

My DDx for common causes of chest pain is as follows (I keep this in the back of my mind to guide my history and physical assessment):

1. Cardiovascular
   1. Ischemic 
      1. Acute coronary syndromes 
      2. Stable ischemic heart disease 
   2. Non-ischemic 
      1. Aortic aneurysm 
      2. Pericarditis 
2. Pulmonary or mediastinal 
   1. Pulmonary embolus or pulmonary infarct 
   2. Pleuritis 
   3. Pneumothorax 
   4. Malignancy 
3. Gastro-intestinal 
   1. Esophageal spasm or esophagitis 
   2. Peptic ulcer disease 
   3. Mallory-Weiss syndrome 
   4. Biliary disease or pancreatitis 
4. Chest wall pain (ex: costochondritis) 
5. Anxiety disorders 

As you ran through the above list, you may have been thinking, "Oh, but what about this disease, and this other one, and this other one." There are a TON of possible reasons for chest pain, and the above list is simply a sample of causes for which patient may present with chest pain as their main concern. So, for example, a patient with a pneumonia may very well have chest pain as a symptom, but they are also more likely to present with shortness of breath. Hence the importance of starting with a complete history in the stable patient. Apart from the characterization of the chest pain using your go to history-taking mnemonic, it is also important to consider a patient's risk factors for cardiac other disease processes. Significant cardiac risk factors include:

1. Demographics: Male, age >55 yrs
2. Past medical history: Diabetes mellitus, dyslipidemia, hypertension
3. Tobacco, cocaine/amphetamine use
4. Family history of CAD

When it comes to chest pain, sometimes the diagnosis is apparent based on history alone. However, more often, the history simply narrows the differential, without having the capacity to point to a specific culprit by itself. As UpToDate states, "Thoracic organs share afferent nervous system pathways. This creates significant overlap in the symptoms patients experience when thoracic organs develop disease, and makes it difficult to distinguish which organ system is involved purely on the basis of history. Patient descriptions of their symptoms can be helpful in some instances, but (...) clinicians must guard against premature diagnostic closure based upon history. Several studies demonstrate that so-called "atypical" presentations occur more often than was previously thought and misinterpretation of such presentations increases the risk for misdiagnosis and adverse outcomes." So while history is a very important component of the evaluation of the patient presenting with chest pain, keeping an initially broad differential and narrowing this down as indicated is the safest strategy. This is particularly important when it comes to the diagnosis of ischemic heart disease, be it in the emergency department or outpatient clinic setting. Myocardial infarction is a huge burden on mortality and morbidity in the population, and intervening during an acute myocardial infarction or addressing symptoms of ischemic heart disease that portend a future MI can make a huge difference on the patient's quality of life (see my next post for symptoms of stable ischemic heart disease). Unless you feel confident the patient is presenting with symptoms attributable to separate disease processes only, investigate for ischemic heart disease always. And remember, this is relevant for the atypical presentations too, in which ischemic heart disease my present as simply dyspnea, weakness, fatigue, or epigastric pain. These atypical presentations of ischemic heart disease may be more common in women, those at the extremes of age (young or elderly), patients with diabetes, and those who may have no cardiac risk factors whatsoever. 

Below is an approach to chest pain from UpToDate. In any patient with new ongoing chest pain, they warrant an ECG to rule out cardiac ischemia (as well as to look for clues of other etiologies that may present with ECG findings), unless the chest pain is obviously from another etiology.