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 9). In: Sloan PD, Slatt LM, Ebell MH, Smith MA, eds. Essentials of Family Medicine, 6th ed. Philadelphia, PA: Wolters Kluwer/Lippincott, Williams and Wilkins, 2012, 99-112. 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

Ebell, MH, Evaluation of Chest Pain in Primary Care Patients. Am Fam Physician.  2011 Mar 1; 83 (5):603-605.

A 35 year old woman comes to clinic with a 1 hour history of chest pain and diaphoresis that began while she was sitting at her desk.  She describes a pressure radiating to both arms.  She is a smoker.  No history of hypertension, diabetes, or family history of cardiac disease.  She 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.  She has no murmurs, gallops or rubs on exam.  Lungs are clear.  She has no tenderness.  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
• aortic 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
  • Prinzmetal (variant) angina

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?  What is this patient’s risk according to the clinical decision rule in the Ebell article?

Assess risk factors (diabetes, hyperlipidemia, family history of premature CAD, smoking, obesity, hypertension) is useful in prevention and long term prediction but are not useful in discriminating cardiac from noncardiac causes in the acute setting.

This patient would fall into the low risk classification (her pain is not reproducible).

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 new LBBB, new ST elevation >0.5 mm or ST depression >1 mm in two or more leads, T wave hyperacuity or inversion in two or more leads, or Q waves to indicate acute cardiac ischemia
  • 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 ¯ V1 – V3 – posterior
  • diffuse ST ­ - pericarditis – new LBBB
• CXR – look for cardiomegaly, pulmonary disease, mediastinal widening, fracture, mass, pneumothorax
• Serial enzymes
  • myoglobin
  • CK MB – low sensitivity till 4-12 h after onset of pain
  • Troponin sensitive, specific, early rise in MI (within 6 hours)
• Stress testing
  • Stress EKG (exercise or pharmacologic)
  • Thallium (Mi perfusion)
  • stress echo
  • angiogram
• Response to therapy – nitroglycerin can improve pain in cardiac ischemia or esophageal spasm, antacids help in GI causes

Question 7:  How might women present differently than men?  What are special challenges with female patients in the evaluation of chest pain? 

Women are more likely to have "atypical chest pain"  (often pain in the neck, back, or epigastrium).  Women and their physicians often don’t recognize these symptoms as cardiac. 

Women have a high false positive rate on exercise stress testing.  Experts recommend using immediate radionuclide imaging or stress echocardiography.

Question 8:  How might the presentation change for a diabetic patient?  An elderly patient?

Diabetic patients often feel little or no pain.  Elderly patients often have shortness of breath instead of pain.  Patients over 65 often have unreliable results on stress ECG testing as well.

Question 9:  How would you manage this patient?

According to the clinical decision rule presented in the Ebell article, this patient should be evaluated for noncardiac causes of chest pain unless there are other reasons for concern.  An EKG may have been avoided in this patient, though many physicians would order one anyway.  Because this was ordered, it may prompt following the moderate risk pathway with a nonconcerning EKG (serial troponins). This does not add any statistical value to the analysis, but it may help reassure a worried patient or provide opportunities for education about lifestyle modification.

CASE 2

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.  His blood pressure is 142/94.  02 saturation is 97% on room air and his pulse is about 130. His pain is not reproducible. 

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

• chest pressure
• radiation
• diaphoresis
• feeling of impending doom               
• 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.  According to the referenced clinical decision rule, he would be a moderate risk patient, necessitating an EKG evaluation and either stress testing or serial troponin levels.

If he does have ischemia/infarction, Aspirin has proven strong benefit in reducing mortality. IV beta blockers are contraindicated in unstable patients due to increased risk for cardiogenic shock, but they may have a net benefit for stable patients.  Oral beta blockers can reduce death and reinfarction rates and should be initiated within 24 hours if there is no sign of CHF.  Metoprolol is preferred over atenolol.  ACE inhibitors are indicated within 24 hours and may reduce mortality in patients who have an MI.  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. Reperfusion therapy (thrombolytic or emergent PCI) is essential in patients with ST elevation, new LBBB, or ST depression in anterior precordial leads.  Thrombolytic therapy must be initiated within 6 hours of symptom onset (perhaps 12 hours) if there are no contraindications.  PCI should occur within 90 minutes of patient presentation.

Treatment for chronic CAD would include continued aspirin and beta blocker therapy, smoking cessation, lipid management, long-acting CCBs, avoidance of NSAIDs.  Revascularization may be indicated based on angiogram results.