Instructor version of discussion cases: Chest Pain

Learning Objectives:

• Define the accuracy of the initial EKG, labs, etc., in the diagnosis of cardiac disease in the ED or office
• Define the role and significance (or lack thereof) of risk factors such as diabetes, family history, smoking and hypertension in the decision of whether or not to admit a patient for cardiac disease
• Define the roles of various diagnostic tests in the diagnosis of possible pulmonary embolism
• Discuss the differential diagnosis of chest pain

Suggested Readings:
Green LA, Rodgers PE, Chest Pain (Chapter 24). In: Sloan PD, Slatt LM, Ebell MH, Jacques LB, eds. Essentials of Family Medicine, 4th ed. Philadelphia, PA: Lippincott, Williams and Wilkins, 2002, 395 - 417. Note: This is the required text for the FM Preceptorship.

Panju AA, et al. Is This Patient Having a Myocardial Infarction? JAMA 1998;280:1256-63. May be accessed at: http://jama.ama-assn.org/cgi/reprint/280/14/1256.pdf

A 35 year old female comes to your clinic with a 1 hour history of chest pain. The pain is described as a pressure radiating to both arms. She is a smoker. No history of hypertension, diabetes, or family history of cardiac disease. She is diaphoretic and has a normal blood pressure. She blames the diaphoresis on the fact that it is hot outside with a high humidity, and she has just walked in from the parking lot. She looks relatively calm and comfortable. Her EKG shows nonspecific ST-T changes without other abnormalities.

Question 1: What is the differential diagnosis of chest pain?

• chest wall pain, musculoskeletal, costochondritis
• aortic dissection - > 60, HTN, severe pain with normal EKG
• aostic stenosis: angina/dyspnea/syncope
• pericarditis
• myocarditis
• GERD, esophageal dysmotility, spasm, esophagitis
• pulmonary embolus
• pulmonary hypertension
• pulmonary parenchymal: pneumonia, cancer, sarcoid, pneumothorax
• pleuritic (pneumothorax, viral pleuritis, pneumonia)
• psychogenic/panic
• referred pain - gallbladder
• cardiac ischemia
  • - ischemia
  • - stable angina
  • - acute MI

Question 2: What is the differential of cardiac chest pain?

Note: One-third of cardiac patients have no chest pain!

• stable angina
• unstable angina
• acute MI acute coronary syndrome
  • unstable angina and acute MI acute coronary syndrome = acute coronary syndrome

Unstable angina is:

• rest angina
• crescendo angina
• change in angina pattern
• new angina
• perioperative angina

Question 3: What historical features help you better characterize it as cardiac versus noncardiac chest pain?

Assessment risk factors: (diabetes, hperlipidemia, family history of premature CAD, smoking, obesity, hypertension) is useful in prevention an lng tem prediction but are not useful in discriminating cardiac from noncardiac causes in the acute setting.

Question 4: Which has the highest likelihood ratio of being associated with cardiac disease, right arm radiation, left arm radiation or pain to both arms?

Pain may radiate to neck, throat, lower jaw, teeth and upper extremity, shoulder. Wide extension increases odds for chest pain of cardiac origin. Radiation to both arms is a stronger predictor of cardiac chest pain. 

Question 5: What physical findings increase the likelihood that chest pain is due to a cardiac source?

Hypotension - S3 - Pulmonary crackles - Diaphoresis - (Dyspnea is not a strong indicator!) 

Question 6: What lab tests or other studies do you want to order and how will you use the results in your decision making?

• Serial EKG - 20% are normal in unstable angina - look for LBBB, new ST change, or Q waves to indicate cardiac cause
  • ST/TW changes - ischemic
  • ST elevation in V₁ - V₃ - anteroseptal (LAD)
  • ST elevation in V₄ - V₆ - apical/lateral
  • ST elevation in II, III, AVF - inferior (RCA + LCX)
  • reciprocal ST decrease V₁ - V₃ - posterior
  • diffuse ST increase - pericarditis - new LBBB
• CXR - look for cardiomegaly, pulmonary disease
• Serial enzymes
  • myoglobin
  • CK MB - low sensitivity till 4-12 h after onset of pain
  • Troponin sensitive, specific, early rise in M1 (within 6 hours)
• Stress testing (Exercise or pharmacologic)
  • Thallium (Mi perfusion)
  • stress echo
  • angiogram
  • GXT
• Response to therapy - nitroglycerin can improve pain in cardiac ischemia or esophageal spasm, antacids help in GI causes 

55 year old man with no prior history of cardiac disease presents stating he feels as though he is going to die. He notes chest pain that reached a maximum intensity about 10 minutes after it started. It is described as a pressure that radiates to his left arm. He complains of dyspnea, is diaphoretic and appears in distress. He has a long history of smoking and hypertension but a negative family history. When questioned, the patient notes that he also has a past history of depression but has been fine for the past 10 years or so. His job is stressful but no more than usual, and he usually handles things pretty well. 0₂ saturation is 97% on room air and his pulse is about 130. 

Question 1: What signs and symptoms does this patient display that are consistent with cardiac disease?

• chest pressure
• radiation
• diaphoresis
• distress
• dyspnea
• crescendo pattern of pain
• tachycardia

Question 2: What signs and symptoms does this patient have that are associated with panic disorder?

• "going to die"
• dyspnea
• tachycardia

Question 3: What would you do for this patient?

Subjective discussion about whether he should be admitted to rule out MI or not.

Aspirin and beta-blockers have proven benefit in reducing mortality. Heparin adds little benefit. Nitroglycerin reduces preload and afterload and provides good pain relief. Morphine reduces pain and anxiety. Oxygen and bed rest are often used but are not proven to be beneficial.

A 25 year old female on oral contraceptives comes in complaining that she had a syncopal episode about one hour ago and was transiently short of breath. She notes that her pulse rate was elevated but is now normal. No real chest pain is noted by the patient, but she has vague twinges in her chest when she breathes. No leg swelling or other edema. No fever, chills, cough. Her oxygen saturation is 97%, her pulse is 110 and respiratory rate is 22. The rest of her exam is normal.

Question 1: What are the risk factors for PE? Does this patient have any risk factors?

• Immobilization
• Recent surgery
• Stroke or prior venous thromboembolism
• DVT
• Malignancy
• Fractured/sprained limb
• Factor V Leyden
• Antiphospholipid Syndrome
• Trauma
• Exogenous estrogen use

  This patient uses oral contraceptives (presumably containing estrogen) which is her only reported risk factor. 

Question 2: What are the symptoms and signs of PE? Does this patient exhibit any such signs and symptoms?

Symptoms:

• dyspnea (73%)*
• pleuritic CP (66%)*
• cough (37%)
• hemoptysis (13%)

Signs:

• tachypnea (70%)*
• rales (51%)
• tachycardia (30%)
• S4 (24%)
• fever (14%) > 103
• hypotension
• lower extremity DVT

  This patient exhibits signs and symptoms indicated by asterisks. 

Question 3: What are the laboratory tests that can help you in the diagnosis of PE?

None are very helpful in ruling in PE, but can support diagnosis.

• ABG's - hypoxemia - hypo or hypercapnia, increased A-a gradient
• Troponin increase in some cases
• EKG with nonspecific changes
• CXR - atelectasis, pleural effusion, cardiomegaly
• D-dimer
  • degradation of cross linked fibrin
  • good predictive value negative if < 500 ng/mL
  • high sensitivity
  • low specificity
  • Do not use in post op or hospitalized patients or those with a known malignancy 

Question 4: What is currently the best imaging test for diagnosis PE? What is the role of spiral CT?

• Angiogram - gold standard
• VQ Scan - if normal excludes diagnosis
  • High
  • Low probability
  • Intermediate
• CT - controversial, varied sensitivity 57-98% Widely Used. In a study of 1015 patients with negative CT, less than 2% had a subsequent PE in 3 months 

Question 5: Would you Doppler the patient's legs looking for a DVT?

• Doppler can have false negatives and false positives.
• Source of emboli could be upper extremity or pelvic veins.
• Consider if VQ scan or CT is indeterminate and you have a high index of suspicion before proceeding to angiogram.