Chest Discomfort¶
Chapter 15 | Part 2: Cardinal Manifestations and Presentation of Diseases
KEY CLINICAL POINTS¶
- Chest discomfort is one of the most common ED presentations (6-7 million visits/year in US); fewer than 15% are eventually diagnosed with ACS
- Initial assessment must rapidly identify life-threatening causes: ACS, acute aortic syndrome, pulmonary embolism, tension pneumothorax, and pericarditis with tamponade
- Quality, location, pattern, and associated symptoms are pivotal in formulating clinical impression; typical anginal pain is pressure/tightness, retrosternal with radiation to arms/jaw
- High-sensitivity troponin with serial testing (1-3h) combined with clinical decision pathways achieves 'miss rates' for ACS of <0.5%
- Gastrointestinal disorders are the most common cause of nontraumatic chest discomfort (42%), followed by ischemic heart disease (31%)
1. DEFINITION & OVERVIEW¶
Chest discomfort is among the most common reasons patients present for medical attention at emergency departments or outpatient clinics. The evaluation is inherently challenging due to the broad variety of possible causes, with a minority being life-threatening conditions that must not be missed. The initial diagnostic assessment and triage should be framed around three categories: 1. Myocardial ischemia 2. Other cardiopulmonary causes (myopericardial disease, aortic emergencies, pulmonary conditions) 3. Noncardiopulmonary causes While rapid identification of high-risk conditions is a priority, strategies incorporating routine liberal use of testing carry potential for adverse effects from unnecessary investigations.
1.1 Clinical Framework for Assessment¶
A series of structured questions guides evaluation: 1. Could the discomfort be due to an acute, potentially life-threatening condition? (Unstable ischemic heart disease, aortic dissection, pneumothorax, pulmonary embolism) 2. Could it be due to a chronic condition likely to lead to serious complications? (Stable angina, aortic stenosis, pulmonary hypertension) 3. Could it be due to an acute condition warranting specific treatment? (Pericarditis, pneumonia/pleuritis, herpes zoster) 4. Could it be due to another treatable chronic condition? (Esophageal reflux/spasm, peptic ulcer disease, gallbladder disease, musculoskeletal disorders, anxiety)
2. EPIDEMIOLOGY¶
Chest discomfort is one of the three most common reasons for ED visits in the United States.
2.1 Incidence and Healthcare Utilization¶
- 6-7 million emergency visits per year in the US
-
60% of patients with this presentation are hospitalized for further testing
- Most of the remainder undergo additional investigation in the ED
- Fewer than 15% are eventually diagnosed with acute coronary syndrome (ACS)
- ACS rates: 10-20% in most unselected populations; as low as 5% in some studies
2.2 Distribution of Final Diagnoses¶
- Gastrointestinal causes: 42%
- Ischemic heart disease: 31%
- Chest wall syndrome: 28%
- Pericarditis: 4%
- Pleuritis: 2%
- Pulmonary embolism: 2%
- Lung cancer: 1.5%
- Aortic aneurysm: 1%
- Aortic stenosis: 1%
- Herpes zoster: 1% In a large proportion of patients with transient acute chest discomfort, ACS or another acute cardiopulmonary cause is excluded but the cause is not determined. As few as 5% are other life-threatening cardiopulmonary conditions.
2.3 Missed Diagnosis Rates¶
Historically, 2-6% of patients with chest discomfort of presumed nonischemic etiology who are discharged from the ED were later deemed to have had a missed myocardial infarction (MI). The estimated rate of major cardiovascular events through 30 days in patients with acute chest pain stratified as low risk was 2.5% in a large population-based study (excluding ST-segment elevation or definite noncardiac chest pain).
3. ETIOLOGY & PATHOPHYSIOLOGY¶
The causes of chest discomfort can be broadly categorized into cardiopulmonary and noncardiopulmonary etiologies, each with distinct pathophysiologic mechanisms.
Typical Clinical Features of Major Causes of Acute Chest Discomfort¶
| System/Condition | Onset/Duration | Quality | Location | Associated Features |
|---|---|---|---|---|
| CARDIAC - Myocardial Ischemia (Stable Angina) | Precipitated by exertion, cold, or stress; 2-10 min | Pressure, tightness, squeezing, heaviness, burning | Retrosternal; often radiation to neck, jaw, shoulders, or arms; sometimes epigastric | S4 gallop or mitral regurgitation murmur (rare) during pain; S3 or rales if severe ischemia or complication of MI |
| System/Condition | Onset/Duration | Quality | Location | Associated Features |
|---|---|---|---|---|
| CARDIAC - Myocardial Ischemia (Unstable Angina) | Increasing pattern or at rest | Pressure, tightness, squeezing, heaviness, burning | Retrosternal; often radiation to neck, jaw, shoulders, or arms; sometimes epigastric | S4 gallop or mitral regurgitation murmur (rare) during pain; S3 or rales if severe ischemia or complication of MI |
| CARDIAC - Myocardial Infarction | Usually >30 min | Pressure, tightness, squeezing, heaviness, burning | Retrosternal; often radiation to neck, jaw, shoulders, or arms; sometimes epigastric | S4 gallop or mitral regurgitation murmur (rare) during pain; S3 or rales if severe ischemia or complication of MI |
| CARDIAC - Pericarditis | Variable; hours to days; may be episodic | Pleuritic, sharp | Retrosternal or toward cardiac apex; may radiate to left shoulder | May be relieved by sitting up and leaning forward; pericardial friction rub |
| VASCULAR - Acute Aortic Syndrome | Sudden onset of unrelenting pain | Tearing or ripping; knifelike | Anterior chest, often radiating to back, between shoulder blades | Associated with hypertension and/or underlying connective tissue disorder; murmur of aortic insufficiency; loss of peripheral pulses |
| VASCULAR - Pulmonary Embolism | Sudden onset | Pleuritic; may manifest as heaviness with massive PE | Often lateral, on the side of the embolism | Dyspnea, tachypnea, tachycardia, and hypotension |
| VASCULAR - Pulmonary Hypertension | Variable; often exertional | Pressure | Substernal | Dyspnea, signs of increased venous pressure |
| PULMONARY - Pneumonia/Pleuritis | Variable | Pleuritic | Unilateral, often localized | Dyspnea, cough, fever, rales, occasional rub |
| PULMONARY - Spontaneous Pneumothorax | Sudden onset | Pleuritic | Lateral to side of pneumothorax | Dyspnea, decreased breath sounds on side of pneumothorax |
| GI - Esophageal Reflux | 10-60 min | Burning | Substernal, epigastric | Worsened by postprandial recumbency; relieved by antacids |
| GI - Esophageal Spasm | 2-30 min | Pressure, tightness, burning, intense squeezing | Retrosternal | Can closely mimic angina; may be relieved by nitroglycerin or dihydropyridine CCBs |
| GI - Esophageal Injury | Prolonged | Intense squeezing | Retrosternal | Includes Mallory-Weiss tear or esophageal rupture (Boerhaave's syndrome) from vomiting |
| System/Condition | Onset/Duration | Quality | Location | Associated Features |
|---|---|---|---|---|
| GI - Peptic Ulcer | Prolonged; 60-90 min after meals | Burning | Epigastric (most common), substernal | Relieved with food or antacids |
| GI - Gallbladder Disease | Prolonged; steady, usually hours | Aching or colicky | Epigastric, RUQ; sometimes to back, scapula, lower chest | May follow meal and may subside spontaneously |
| GI - Pancreatitis | Prolonged | Typically aching | Epigastric, radiates to the back | |
| NEUROMUSCULAR - Costochondritis | Variable | Aching | Sternal | Sometimes swollen, tender, warm over joint; may be reproduced by localized pressure |
| NEUROMUSCULAR - Cervical Disk Disease | Variable; may be sudden | Aching; may include numbness | Arms and shoulders | May be exacerbated by movement of neck |
| NEUROMUSCULAR - Trauma/Strain | Usually constant | Aching | Localized to area of strain | Reproduced by movement or palpation |
| NEUROMUSCULAR - Herpes Zoster | Usually prolonged | Sharp or burning | Dermatomal distribution | Vesicular rash in area of discomfort |
| PSYCHOLOGICAL - Emotional/Psychiatri c | Variable; may be fleeting or prolonged | Variable; often tightness and dyspnea with feeling of panic/doom | Variable; may be retrosternal | Situational factors may precipitate; history of panic attacks, depression |
3.1 Myocardial Ischemia/Injury¶
Myocardial ischemia causing chest discomfort (angina pectoris) is a primary clinical concern. It is precipitated by an imbalance between myocardial oxygen requirements and supply, resulting in insufficient oxygen delivery to meet metabolic demands. Determinants of Myocardial Oxygen Consumption: - Heart rate - Ventricular wall stress - Myocardial contractility Determinants of Myocardial Oxygen Supply: - Coronary blood flow - Coronary arterial oxygen content Pathophysiology of Injury: When ischemia is sufficiently severe and prolonged (as little as 20 minutes), irreversible cellular injury occurs, resulting in MI.
3.2 Classification of Ischemic Heart Disease¶
Stable Angina: Ischemic episodes typically precipitated by superimposed increase in oxygen demand during physical exertion; relieved upon resting. Unstable Ischemic Heart Disease: - Unstable Angina: No detectable acute myocardial injury - NSTEMI: Acute myocardial injury without ST-segment elevation - STEMI: Acute myocardial injury with ST-segment elevation MI Classification System: - Type 1 MI: Results from acute coronary thrombosis - Type 2 MI: Occurs secondary to other imbalances of myocardial oxygen supply and demand Secondary Causes of Ischemia: - Increased demand: Intense psychological stress - Decreased oxygen delivery: Anemia, hypoxia, hypotension - Extreme demand with impaired endocardial blood flow: Aortic valve disease, hypertrophic cardiomyopathy, idiopathic dilated cardiomyopathy
3.3 Pericardial and Myocardial Diseases¶
Pericarditis: - Visceral surface and most parietal surface are insensitive to pain - Pain arises principally from associated pleural inflammation - Pleuritic nature: exacerbated by breathing, coughing, or position changes - Central diaphragm (via phrenic nerve) has overlapping sensory supply with C3-C5 somatic fibers → pain referred to shoulder/neck - Lateral diaphragm involvement → upper abdominal pain Myocarditis: - Highly varied symptoms - Pain may originate from inflammatory injury or severe wall stress from poor ventricular performance Takotsubo (Stress-Related) Cardiomyopathy: - Abrupt onset with chest pain and shortness of breath - Triggered by emotional or physical stress - May mimic acute MI (ST-segment elevation, elevated troponin)
3.4 Diseases of the Aorta¶
Acute Aortic Syndromes encompass a spectrum of acute aortic diseases related to disruption of the aortic wall media: - Acute aortic dissection - Penetrating ulcer - Intramural hematoma Risk Factors (nontraumatic dissections very rare without these): - Hypertension - Pregnancy - Bicuspid aortic disease - Inherited connective tissue diseases (Marfan syndrome, Ehlers-Danlos syndrome) Location Patterns: - Ascending aorta: Midline anterior chest pain - Descending aorta: Pain in the back - Ascending extending to descending: Front chest pain extending to back between shoulder blades
3.5 Pulmonary Embolism¶
Produces dyspnea and sudden-onset chest discomfort. Three mechanisms for pain: 1. Pleural surface involvement adjacent to pulmonary infarction (lateral, pleuritic pain - small emboli) 2. Distention of pulmonary artery 3. RV wall stress/subendocardial ischemia from acute pulmonary hypertension Massive PE may cause severe substernal pain mimicking MI (mechanisms 2 and 3), syncope, hypotension, and signs of right heart failure.
3.6 Pneumothorax¶
Primary Spontaneous Pneumothorax: - Rare cause of chest discomfort - Risk factors: Male sex, smoking, family history, Marfan syndrome - Usually sudden onset; dyspnea may be mild → delayed presentation Secondary Spontaneous Pneumothorax: - Underlying lung disorders (COPD, asthma, cystic fibrosis) - More severe symptoms Tension Pneumothorax: - Medical emergency - Trapped intrathoracic air causing hemodynamic collapse
3.7 Other Pulmonary Conditions¶
Most pulmonary diseases producing chest pain (pneumonia, malignancy) do so via pleural or surrounding structure involvement. - Pleurisy: Knifelike pain worsened by inspiration/coughing - Chronic Pulmonary Hypertension: May present with angina-like pain suggesting RV myocardial ischemia - Reactive Airways Disease: Chest tightness with breathlessness rather than pleurisy
3.8 Gastrointestinal Conditions¶
Most common cause of nontraumatic chest discomfort. Esophageal disorders particularly may simulate angina. - Esophageal Reflux: Burning substernal/epigastric pain; worsened by postprandial recumbency; relieved by antacids - Esophageal Spasm: Pressure/tightness/burning; retrosternal; can closely mimic angina; may be relieved by nitroglycerin or dihydropyridine CCBs - Esophageal Injury: Mallory-Weiss tear or esophageal rupture (Boerhaave's syndrome) from vomiting - Peptic Ulcer: Burning epigastric pain; symptomatic 60-90 min after meals; relieved by food/antacids - Gallbladder Disease: Aching/colicky RUQ pain; may follow meals - Pancreatitis: Aching epigastric pain radiating to back
3.9 Musculoskeletal and Other Causes¶
- Costochondritis (Tietze's Syndrome): Tenderness of costochondral junctions; relatively common
- Cervical Radiculitis: Prolonged/constant aching in upper chest and limbs; exacerbated by neck movement
- Cervical Rib Compression: Brachial plexus compression
- Shoulder Tendinitis/Bursitis: May mimic angina radiation
- Intercostal Muscle Cramping
- Herpes Zoster: Dermatomal distribution pain with vesicular rash Emotional/Psychiatric Conditions: Up to 10% of ED presentations with acute chest discomfort have panic disorder or related conditions. Hyperventilation can cause nonspecific ST and T-wave abnormalities.
4. CLINICAL FEATURES¶
Characteristics of ischemic chest discomfort (angina pectoris) are highly similar in quality and location whether manifesting as stable ischemic heart disease, unstable angina, or MI.
4.1 Characteristics of Ischemic Chest Discomfort¶
Heberden initially described angina as a sense of "strangling and anxiety." Quality: - Typically: Aching, heavy, squeezing, crushing, or constricting - Substantial minority: Vague - mild tightness, uncomfortable feeling, numbness, or burning sensation - NOT typically: Sharp (knifelike, stabbing, pleuritic) - though patients may use "sharp" to convey intensity Location: - Usually retrosternal - Common radiation: Ulnar surface of left arm; right arm; both arms; neck; jaw; shoulders - Some present with aching at radiated sites as only symptom - Radiation to BOTH arms has particularly high association with MI Pattern: - Stable angina: Builds over minutes; predictably at characteristic level of exertion/stress; dissipates within minutes with rest or nitroglycerin - Unstable angina: Progressively lower intensity of activity or at rest - MI: More severe, prolonged (usually ≥ 30 min), not relieved by rest
4.2 Pain Quality Discriminators¶
Increased Likelihood of AMI: - Radiation to right arm or shoulder - Radiation to both arms or shoulders (highest association) - Associated with exertion - Radiation to left arm - Associated with diaphoresis - Associated with nausea or vomiting - Worse than previous angina or similar to previous MI - Described as pressure Decreased Likelihood of AMI: - Inframammary location - Reproducible with palpation - Described as sharp - Described as positional - Described as pleuritic
4.3 Pattern and Timing¶
- Pain reaching peak immediately: More suggestive of aortic dissection, PE, or spontaneous pneumothorax
- Fleeting pain (few seconds): Rarely ischemic
- Constant for prolonged period (hours to days) without ECG changes, biomarker elevation, or sequelae: Unlikely ischemia
- Morning onset: Both myocardial ischemia and acid reflux
- Highly localized (tip of one finger): Highly unusual for angina
4.4 Provoking and Alleviating Factors¶
Myocardial Ischemia: - Usually prefer to rest, sit, or stop walking - "Warm-up angina": Some experience relief continuing at same/greater exertion - Relief within minutes after nitroglycerin (but >10 min delay suggests non-ischemic or severe ischemia like MI) Against Ischemia: - Altered by position changes or upper extremity/neck movement → suggests musculoskeletal - Note: Chest wall tenderness does NOT exclude ischemia Pericarditis: Worse supine; relieved sitting upright and leaning forward Gastroesophageal Reflux: Exacerbated by alcohol, some foods, reclined position; relieved by sitting GI Causes: Exacerbated by eating; unlikely altered by physical exertion (exception: postprandial angina in severe CAD due to splanchnic redistribution) Esophageal Spasm: May also be relieved by nitroglycerin
4.5 Associated Symptoms¶
With Myocardial Ischemia: - Diaphoresis - Dyspnea - Nausea - Fatigue - Faintness - Eructations - These may exist as anginal equivalents (particularly in women and elderly) Dyspnea: Not discriminative but important - suggests cardiopulmonary etiology Sudden Significant Respiratory Distress: Consider PE and spontaneous pneumothorax Hemoptysis: Usually pulmonary parenchymal etiology; may occur with PE or as blood-tinged frothy sputum in severe heart failure Syncope/Presyncope: Consider hemodynamically significant PE, aortic dissection, ischemic arrhythmias Nausea/Vomiting: Suggest GI disorder but may occur with MI (more commonly inferior MI) - vagal reflex or Bezold-Jarisch reflex
4.6 Location-Specific Patterns¶
- Retrosternal: Classic for angina; also esophageal pain
- Radiation to trapezius ridge: Characteristic of pericardial pain; NOT usual for angina
- Above mandible or below epigastrium: Rarely angina
- Severe pain radiating to back (between shoulder blades): Consider acute aortic syndrome
- Epigastric: GI causes most common; angina may also occur here
5. DIFFERENTIAL DIAGNOSIS¶
The differential diagnosis of chest discomfort is broad and can be organized by organ system and clinical urgency.
5.1 Life-Threatening Conditions Requiring Urgent Evaluation¶
- Unstable ischemic heart disease (unstable angina, NSTEMI, STEMI)
- Acute aortic syndrome (dissection, intramural hematoma, penetrating ulcer)
- Pulmonary embolism (massive or submassive)
- Tension pneumothorax
- Pericarditis with tamponade
- Fulminant myocarditis
5.2 Chronic Conditions Likely to Lead to Serious Complications¶
- Stable angina
- Aortic stenosis
- Pulmonary hypertension
5.3 Acute Conditions Warranting Specific Treatment¶
- Pericarditis (without tamponade)
- Pneumonia/pleuritis
- Herpes zoster
- Esophageal rupture (Boerhaave's syndrome)
5.4 Other Treatable Chronic Conditions¶
Gastrointestinal: - Esophageal reflux - Esophageal spasm - Peptic ulcer disease - Gallbladder disease - Pancreatitis Musculoskeletal: - Costochondritis - Cervical disk disease - Arthritis of shoulder or spine - Trauma or strain Other: - Anxiety state/panic disorder
6. INVESTIGATIONS & DIAGNOSIS¶
The evaluation of nontraumatic chest discomfort relies heavily on clinical history and physical examination to direct subsequent diagnostic testing.
Comparison of HEART and EDACS Decision-Aid Scores¶
| Feature | HEART Score | EDACS Score |
|---|---|---|
| Low Risk Threshold | 0-3 points | 0-15 points |
| Feature | HEART Score | EDACS Score |
|---|---|---|
| Captured as Low Risk | 51.8% | 60.6% |
| Negative Predictive Value | 99.55% | 99.49% |
| Troponin Requirement | < Limit of quantification | < Limit of quantification |
| Key Components | History, ECG, Age, Risk factors | Age, Known CAD/risk factors, Sex, Symptoms |
| Endpoint (60 days) | MI, cardiogenic shock, cardiac arrest, all-cause mortality | MI, cardiogenic shock, cardiac arrest, all-cause mortality |
6.1 History Taking¶
Assess: - Quality of pain - Location (including radiation) - Pattern (onset and duration) - Provoking or alleviating factors - Associated symptoms - Past medical history: Risk factors for CAD, VTE, conditions predisposing to specific disorders (e.g., Marfan syndrome → aortic syndrome or pneumothorax)
6.2 Physical Examination¶
General Assessment: - Clinical stability assessment - Appearance: Anxious, uncomfortable, pale, cyanotic, diaphoretic suggests acute cardiopulmonary disorder - Levine's sign: Clenched fist against sternum - Body habitus: Marfan syndrome; tall, thin young man (pneumothorax) Vital Signs: - Tachycardia + hypotension: Consider MI with cardiogenic shock, massive PE, tamponade, tension pneumothorax - Acute aortic emergencies: Usually severe hypertension; may be profound hypotension with coronary compromise or pericardial dissection - Sinus tachycardia: Important manifestation of submassive PE - Tachypnea/hypoxemia: Pulmonary cause - Low-grade fever: Nonspecific (MI, thromboembolism, infection) Pulmonary: - May localize primary pulmonary cause (pneumonia, asthma, pneumothorax) - Rales: LV dysfunction from severe ischemia/infarction or acute valvular complications Cardiac: - JVP: Usually normal in acute ischemia; characteristic patterns with tamponade or acute RV dysfunction - S3: Systolic dysfunction - S4 (more common): Diastolic dysfunction - Murmurs: Mitral regurgitation or VSD (mechanical MI complications); aortic insufficiency (ascending dissection complication); underlying cardiac disorders (AS, HCM) - Pericardial friction rub: Pericardial inflammation Abdominal: - Localizing tenderness: GI etiology - Hepatic congestion: Right-sided heart failure Extremities: - Chronic pulse deficits: Underlying atherosclerosis (increases CAD likelihood) - Acute limb ischemia (loss of pulse, pallor, especially upper extremities): Catastrophic aortic dissection - Unilateral leg swelling: VTE Musculoskeletal: - Localized swelling, redness, marked tenderness at costochondral/chondrosternal articulations: Costochondritis - Deep palpation may elicit pain without costochondritis - Chest wall tenderness does NOT exclude myocardial ischemia - Upper extremity sensory deficits: Cervical disk disease NOTE: Physical exam may be normal in unstable ischemic heart disease; unremarkable exam is not definitively reassuring
6.3 Electrocardiography¶
Crucial in evaluation; obtain within 10 minutes of presentation. Primary Goals: - Identify STEMI candidates for immediate revascularization - Detect ischemia in absence of STEMI Findings Indicative of Ischemia: - ST-segment elevation: Diagnostic of STEMI - ST-segment depression: Ischemia, higher risk - Symmetric T-wave inversions ≥ 0.2 mV: Ischemia, higher risk Serial ECGs: - Recommended every 30-60 min early in ED evaluation of suspected ACS - Right-sided lead placement: Consider in suspected ischemia with nondiagnostic standard 12-lead Limitations: - Sensitivity for ischemia is poor (as low as 20% in some studies) Other Conditions Causing ST/T Abnormalities: - Pulmonary embolism - Ventricular hypertrophy - Acute and chronic pericarditis - Myocarditis - Electrolyte imbalance - Metabolic disorders - Hyperventilation (panic disorder) PE Findings: - Most often: Sinus tachycardia - S-wave in lead I, Q-wave and T-wave in lead III (S1Q3T3) - Rightward axis shift Pericarditis vs MI Differentiation: - Diffuse ST elevation not following coronary distribution - PR-segment depression
6.4 Chest Radiography¶
Routine in acute chest discomfort; selective in outpatient subacute/chronic pain. Most Useful For: - Identifying pulmonary processes (pneumonia, pneumothorax) Specific Findings: - ACS: Often unremarkable; pulmonary edema may be evident - Aortic dissection: Mediastinal widening (some patients) - Pulmonary embolism: Hampton's hump, Westermark's sign - Chronic pericarditis: Pericardial calcification
6.5 Cardiac Biomarkers¶
Cardiac Troponin: - Preferred biomarker for MI diagnosis - Should be measured in ALL patients with suspected ACS - NOT necessary/advisable in patients without ACS suspicion (unless for specific risk stratification in PE or heart failure) High-Sensitivity Troponin Assays (Preferred): - Greater analytical sensitivity - Enhanced diagnostic accuracy - Improved risk stratification - Greater negative predictive value Timing of Troponin Measurement: - At presentation - Repeat at 1-3 h (high-sensitivity) or 3-6 h (conventional assays) - Additional measurements may be warranted beyond 3-6 h if clinical suspicion persists - Patients presenting >2-3 h after symptom onset: Very low high-sensitivity troponin at presentation may be sufficient to exclude MI (NPV >99%) Rapid Rule-Out Protocols: - Serial testing and changes over 1-2 h perform well for diagnosis with high-sensitivity assays Interpretation (Figure 15-3): Elevated cTn Concentration: - Dynamic cTn (significant rise or fall) + Ischemia = MI (Type 1 or Type 2) - Dynamic cTn + No ischemia = Acute myocardial injury (not MI) - Stable cTn = Chronic myocardial injury (structural heart disease, ESRD, interfering antibodies) Caveats: - Initial biomarkers may be normal even in STEMI (time needed for release) - High-sensitivity assays detect injury in larger proportion of non-ACS cardiopulmonary conditions - Rising/falling pattern needed to discriminate acute from chronic elevation - Diagnosis of MI reserved for acute myocardial injury that is ischemia-caused with values exceeding 99th percentile Other Laboratory Tests: - D-dimer: Aid in PE exclusion - B-type Natriuretic Peptide (BNP): Heart failure diagnosis (in conjunction with history/exam)
6.6 Integrative Decision-Aids¶
Clinical decision pathways (CDPs) estimate: 1. Probability of final ACS diagnosis 2. Probability of major cardiac events during short-term follow-up Recommended Use: - Categorize patients as low, intermediate, and high risk - Identify low clinical probability patients who can be discharged without additional noninvasive testing Common Elements Across Risk Stratification Tools: 1. Symptoms typical for ACS 2. Older age 3. Risk factors for or known atherosclerosis 4. Ischemic ECG abnormalities 5. Elevated cardiac troponin level Performance: - Clinical application of CDPs with ECGs and serial high-sensitivity troponin achieves overall "miss rates" for ACS of <0.5% - Protocol-driven care in dedicated chest pain units has decreased costs and evaluation duration with no detectable excess adverse outcomes Important Distinction: - Diagnostic algorithms differ from prognostic risk scores (TIMI, GRACE) used AFTER ACS diagnosis is established
6.7 HEART Score¶
Components (without troponin): History: - Highly suspicious: 2 points - Moderately suspicious: 1 point - Slightly suspicious: 0 points ECG: - Significant ST depression: 2 points - Nonspecific abnormality: 1 point - Normal: 0 points Age: ≥ 65 years: 2 points - 45-<65 years: 1 point - <45 years: 0 points Risk Factors: ≥ 3 risk factors: 2 points - 1-2 risk factors: 1 point - None: 0 points Risk Stratification: - Low risk: 0-3 points - Not low risk: ≥ 4 points AND cardiac troponin < limit of quantification Performance: - Captured as low risk: 51.8% - NPV: 99.55% (for composite endpoint of MI, cardiogenic shock, cardiac arrest, all-cause mortality by 60 days)
6.8 EDACS Score¶
Emergency Department Assessment of Chest Pain Score: Age: - 86+ years: 20 points - 81-85 years: 18 points - 76-80 years: 16 points - Step down by 5-year increments: -2 points each - 46-50 years: 4 points - 18-45 years: 2 points Known CAD or Risk Factors: - Known CAD (prior MI, PCI, or CABG) OR ≥ 3 cardiac risk factors in patient aged ≤ 50 years: 4 points Sex: - Male: 6 points - Female: 0 points Symptoms: - Radiation to arm, shoulder, neck, or jaw: 5 points - Diaphoresis: 3 points - Pain with inspiration: -4 points - Reproduced by palpation: -6 points Risk Stratification: - Low risk: 0-15 points - Not low risk: ≥ 16 points AND cardiac troponin < limit of quantification Performance: - Captured as low risk: 60.6% - NPV: 99.49%
6.9 Coronary and Myocardial Stress Imaging¶
For patients in whom life-threatening causes have been reasonably excluded AND clinical assessment determines intermediate/undetermined risk. Options: - Coronary CT angiography - Functional testing (nuclear or echocardiographic imaging preferred) Selection Considerations: - Patient characteristics (body habitus, renal function) - Prior cardiac testing - History of known CAD - Contraindications for specific modalities - Patient preferences CT Angiography: - Emerged as preferred modality - Sensitive for detection of obstructive coronary disease - Enhances speed to disposition in low-intermediate probability patients - Major strength: High NPV of finding no significant stenosis or plaque - Can also exclude aortic dissection, pericardial effusion, and PE Stress Nuclear Perfusion Imaging/Stress Echocardiography: - Alternatives for patients who are candidates for further testing - PREFERRED in patients with known obstructive epicardial disease - Superior diagnostic performance over exercise ECG alone - Exercise stress preferred over pharmacologic testing when patient able to exercise - Selection depends on institutional availability and expertise
7. MANAGEMENT & TREATMENT¶
Management depends on the underlying etiology identified through the diagnostic evaluation. The approach to acute chest discomfort prioritizes identification and treatment of life-threatening conditions.
7.1 Initial Approach¶
Priorities of Initial Clinical Encounter: 1. Assessment of patient's clinical stability 2. Assessment of probability that underlying cause is life-threatening High-Risk Conditions of Principal Concern: - ACS (unstable angina, NSTEMI, STEMI) - Acute aortic syndrome - Pulmonary embolism - Tension pneumothorax - Pericarditis with tamponade - Fulminant myocarditis
7.2 Acute Management by Etiology¶
STEMI: - Immediate interventions to restore flow in occluded coronary artery - ECG within 10 minutes of presentation to identify candidates - See Chapters 284-286 for detailed management NSTEMI/Unstable Angina: - Risk stratification - Anti-ischemic and antithrombotic therapy - See Chapter 285 for detailed management Acute Aortic Syndrome: - Blood pressure control - Urgent surgical consultation - See Chapter 291 for detailed management Pulmonary Embolism: - Anticoagulation - Thrombolysis or embolectomy for massive PE - See Chapter 290 for detailed management Tension Pneumothorax: - Medical emergency - immediate decompression - See Chapter 305 for detailed management Pericarditis with Tamponade: - Pericardiocentesis - See Chapter 281 for detailed management
7.3 Disposition Decisions¶
Candidates for Discharge from ED Without Additional Testing: - Low clinical probability of ACS identified by evidence-based CDPs - AND cardiac troponin < limit of quantification Candidates for Further Testing: - Intermediate or undetermined risk after clinical assessment - Life-threatening causes reasonably excluded - Serial biomarker and clinical assessment still eligible for testing Options for Further Testing: - Coronary CT angiography (preferred for most; excludes multiple diagnoses) - Stress nuclear perfusion imaging - Stress echocardiography (preferred for known obstructive CAD) Dedicated Chest Pain Units: - Protocol-driven care has been shown to decrease costs and evaluation duration - No detectable excess of adverse clinical outcomes
8. PROGNOSIS & COMPLICATIONS¶
Prognosis varies widely based on underlying etiology.
8.1 Prognosis by Etiology¶
ACS: - Varies by type (STEMI vs NSTEMI vs unstable angina) - See Chapters 284-286 for detailed discussion Acute Aortic Syndrome: - Catastrophic natural history when recognized late or untreated - See Chapter 291 Pulmonary Embolism: - Depends on size and hemodynamic impact - See Chapter 290 Low-Risk Patients with Acute Chest Pain: - Estimated rate of major cardiovascular events through 30 days: 2.5% (population-based study excluding STEMI or definite noncardiac pain) Noncardiopulmonary Conditions: - Generally favorable prognosis during completion of diagnostic workup - Exception: Esophageal rupture holds greatest urgency for diagnosis
8.2 Complications of MI¶
Physical exam may reveal complications: - S3 or rales: LV dysfunction from severe ischemia - Mitral regurgitation murmur: Mechanical complication - Ventricular septal defect murmur: Mechanical complication - Pulmonary edema: Acute valvular complications or LV dysfunction
9. SPECIAL CONSIDERATIONS¶
Certain populations require special attention in the evaluation of chest discomfort.
9.1 Women and Elderly¶
- Anginal equivalents may exist in isolation
- Diaphoresis, dyspnea, nausea, fatigue, faintness, and eructations may be presenting symptoms without typical chest pain
- Heightened awareness needed for atypical presentations
9.2 Patients with Connective Tissue Disorders¶
Marfan Syndrome: - Heightened suspicion for acute aortic syndrome - Heightened suspicion for spontaneous pneumothorax Ehlers-Danlos Syndrome: - Heightened suspicion for acute aortic syndrome
9.3 Pregnancy¶
- Nontraumatic aortic dissection risk factor
- Should be considered in evaluation of pregnant patients with chest pain
9.4 Patients with Known CAD¶
- Functional testing (stress nuclear or stress echo) preferred over CT angiography
- Prior cardiac testing history informs test selection
- Useful to ask about similarity of discomfort to previous definite ischemic symptoms
9.5 Young Adults¶
Primary Spontaneous Pneumothorax: - Typical patient: Young, tall, thin man - Risk factors: Male sex, smoking, family history, Marfan syndrome
10. KEY POINTS & CLINICAL PEARLS¶
Essential clinical pearls for evaluation and management of chest discomfort.
Key Clinical Pearls in Chest Discomfort Evaluation¶
| Category | Pearl |
|---|---|
| Quality | Patients with ischemic chest discomfort may deny "pain" but complain of dyspnea or vague anxiety |
| Quality | Some patients use "sharp" to describe intensity, not quality - clarify meaning |
| Quality | Severity of discomfort has poor diagnostic accuracy |
| Location | Radiation to BOTH arms has particularly high association with MI |
| Category | Pearl |
|---|---|
| Location | Radiation to trapezius ridge is characteristic of pericarditis, NOT angina |
| Location | Pain solely above mandible or below epigastrium is rarely angina |
| Location | Highly localized pain (tip of one finger) is highly unusual for angina |
| Pattern | Pain reaching peak immediately suggests aortic dissection, PE, or pneumothorax |
| Pattern | Fleeting pain (seconds) is rarely ischemic |
| Pattern | Constant pain for hours-days without ECG/biomarker changes or sequelae is unlikely ischemia |
| Alleviating | Relief with nitroglycerin is neither sensitive nor specific - esophageal spasm also responds |
| Alleviating | >10 min delay before nitroglycerin relief suggests non-ischemic or severe ischemia (MI) |
| Physical Exam | Chest wall tenderness does NOT exclude myocardial ischemia |
| Physical Exam | Unremarkable physical exam in unstable ischemic heart disease is common - not definitively reassuring |
| ECG | Sensitivity for ischemia is poor (as low as 20%) - do NOT exclude ischemia based on normal ECG |
| ECG | Obtain within 10 minutes; repeat serially every 30-60 min in suspected ACS |
| Troponin | Initial biomarkers may be normal even in STEMI - serial testing essential |
| Troponin | Rising/falling pattern needed to distinguish acute from chronic elevation |
| Troponin | Diagnosis of MI requires ischemia + acute injury with values exceeding 99th percentile |
| Decision-Making | CDPs with serial high-sensitivity troponin achieve ACS miss rates <0.5% |
| Decision-Making | Diagnostic algorithms differ from prognostic scores (TIMI, GRACE) used after ACS diagnosis |
| Special Populations | Women and elderly may present with anginal equivalents only |
| Special Populations | Marfan syndrome: Consider both aortic syndrome AND pneumothorax |