Chest Pain Evaluation
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Transcript of Chest Pain Evaluation
DIAGNOSING THE CAUSE DIAGNOSING THE CAUSE OF CHEST PAINOF CHEST PAIN
Dr. Rashidi AhmadEmergentist
MD(USM), MMED(USM), FADUSM
School of Medical Sciences
USM Health Campus
Knowledge is a process of pilling up Knowledge is a process of pilling up facts. Wisdom lies in their simplificationfacts. Wisdom lies in their simplification
Martin Luther King, Jr
Introduction
Chest pain is the chief complaint in about 1-2% of outpatient visits.The cause is often non-cardiac BUT heart disease remains the leading cause of death.Chest pain in ED, > 50% due to CV condition.In outpatient primary: musculoskeletal conditions, GIT disease, stable CAD, pulmonary disease, etc.Unstable CAD is rare.15% never reach a definitive diagnosis.
Buntinx F, et al. Chest pain in general practice or in the hospital emergency department: is it the same? Fam Pract 2001;18:586-9.
Epidemiology of Chest pain in primary care setting & ED
Buntinx F, et al. Chest pain in general practice or in the hospital emergency department: is it the same? Fam Pract 2001;18:586-9.
Chest Pain Origin - Difficult?
Various disease processes in a variety of organs.The severity of pain is often unrelated to its life threatening potential.The location of pain perceived by the patient frequently does not correspond with its source.PE, lab Ix, X-rays are often unavailable or non diagnostic.More than one disease process may be present.
Misdiagnosis of ACS
Young patientAtypical presentation & silent ischemiaPoor documentation & incomplete history & physical examinationECG misinterpretationReliance on laboratory assayInexperience doctorHesitance to admit patients with vague symptoms
History
Chest discomfort ~ 80 - 85% Atypical presentation ~ 20%burning/indigestion ~ > 20%chest ache ~ 13%sharp, stabbing pain ~ 5%pain reproduced by palpation ~ 5%Silent ischemia ~ 23%
History
• Up to 33% of patients (elderly & diabetes), who have AMI do not have pain. Canto et al,. JAMA, vol. 283, p. 3223, 2000
• The presence or absence of risk factors does not change the likelihood of cardiac. Graber & et al. Emergency Medicine April 2001
Accuracy of chest pain diagnosis using the Hx & PE
WILLIAM E. CAYLEY, American family Physician. Volume 72, Number 10 , November 15, 2005
Physical examination
Most often normal
Levine’s sign
"No astute clinician is reassured by chest wall tenderness that reproduces a patient's pain, because 15% of patients with acute MI will have chest wall tenderness on palpation that reproduces their pain"
Rosen and Barkin. Emergency Medicine Concepts and Clinical Practice, St. Louis, Mosby, 1999
Electrocardiogram
NOT a perfect indicator of cardiac diseaseONLY 50% with a proven AMI have positive initial ECG indicating the disorderUp to 76% of ACS – normal an initial ECG, non specific, or unchanged from previous ECG Around 5% of chest pain patients with normal ECG who were discharged from the ED were ultimately found to have ACS
Mc Carthy B, Wong J. Detecting acute ischaemia in ED. J Gen Int Med 1990; 5: 381-8
Relation between time & ECG changes
Time Indication of infarct in ECG
1st to 3 hours 40%
4th to 6th hour 50%
7th to 9th hour 90%
10th to 12th hour Up to 100%
Relation between Cardiac markers & time
Cardiac marker Within time of elevation
Myoglobin
1 – 3 hour
CK-MB/Trop I
Troponin T
4 – 8 hour
6 – 8 hour
•At hours: 4 to 8 and 8 to 12 the CPK level is more sensitive (84% and 94%, respectively) in indicating AMI, than is troponin level (74% and 88%, respectively). •After 12 hours: troponin level is essentially 100% sensitive, whereas the CPK level becomes less sensitive
Graber & et al. Emergency Medicine April 2001
Acute Pulmonary embolism
Diagnosing PE requires a high degree of clinical suspicionSharp chest pain - 59%Dyspnea - 78%Cough - 43%Tachycardia - 30%Syncope 13%
Acute Pulmonary embolism
• Not all patients with pulmonary embolus will be hypoxic or have tachycardia or tachypnea.
• Up to 50% of patients with DVT have a silent, or asymptomatic PE.
• Among PE patients without underlying pulmonary disease, ~ 12% have a PaO2>80 mmHG
Meingnan 7 et al. Archives of Internal Medicine, 2000, Vol 160; 159Stein & et al. Chest .1996, Vol. 109, 78
Chest X Ray
Without infarction, the chest x-ray may be normal, or diminished pulmonary vascular markings in the embolized area may be noted.With infarction, the x-rays frequently shows a peripheral infiltrative lesion, with elevation of the diaphragm & pleural fluid on the affected site.
DIAGNOSING THE CAUSE OF CHEST PAIN
William E. Cayley, Jr., M.D., American Family Physician;Vol. 72/no. 10 (November 15, 2005)
Outpatient Diagnosis of Chest pain
Diagnostic test makes sense
Graber & et al. Emergency Medicine April 2001
Likelihood ratios (LR)& Bayes' nomogramare a useful & practical way of expressing the power of diagnostic tests in increasing or decreasing the likelihood of disease
2 methods of estimating the pre-test probability:
Emergency gut feeling (educated guess) after the history & examination Clinical decision rules.
Accuracy of chest pain diagnosis using the Hx & PE
WILLIAM E. CAYLEY, American family Physician. Volume 72, Number 10 , November 15, 2005
•The Rouan decision rule reliably predicts which patients with chest pain & a normal or nonspecific electrocardiogram are at higher risk for MI
•However, 3% of patients initially diagnosed with a non-cardiac cause of chest pain suffer death or MI within 30 days of presentation.
•Patients with cardiac risk factors warrant close follow-up.
•The Diehr diagnostic rule, uses 7 clinical findings to predict the likelihood of pneumonia .
•Other findings that suggest pneumonia include egophony& dullness to percussion, but their absence does not rule out the diagnosis.
•Well’s clinical decision rules for the diagnosis of PE consists of 7 signs & symptoms.
•The strength of the Wells model is that it does not require a CXR or ABG measurements. It relies on a careful history & physical examination.
Accuracy of chest pain diagnosis
using diagnostic & prognostic tests
D-dimer* testing has become an important part of the evaluation for PE & deep venous thrombosis (DVT).
A low clinical suspicion for PE (Wells score <2) plus a normal quantitative ELISA D-dimer assay safely rules out PE, with a negative predictive value >99.5 %.
If further testing is needed, helical computed tomography (CT), combined with clinical suspicion and other testing such as lowerextremity venous ultrasound, can be used to rule in or rule out PE.
* Quantitative enzyme-linked immunosorbent antibody assay (ELISA) D-dimer assays are more sensitive & have been more thoroughly tested in clinical settings than whole-blood agglutination assays.
DIAGNOSTIC TESTING –PULMONARY EMBOLISM
Summary
Although diagnostic tests are impressive, they should not replace the history & physical examination.Clinician decision rule can be given a point score to arrive at a pre-test probability of a disease & help rule in or out specific diagnoses.After history taking & physical examination, we formulate prior probability of the disease –decide as to whether no test, a screening test, or a definitive test should be performed.
SummaryLikelihood ratios (LR) are a useful & practical way of expressing the power of diagnostic tests.An evidence-based approach tailors the diagnostic strategy to the patient - uses clinical evaluation to guide the selection of tests & their interpretation.
“ Having cross the bridge of understanding, we still must cross the bridge to practice ”
William E. Cayley, Jr., M.D., American Family Physician;Vol. 72/no. 10 (November 15, 2005)
Outpatient Diagnosis of Chest pain