1 / 156

Is He Having The Big One?

Is He Having The Big One?. Sirous Partovi, M.D. Department of Emergency Medicine TTUHSC, El Paso. ECG #1- 68 year old with chest pain for 3 days. ECG #2- 66 year old man with 1 hour history of chest pressure. ECG #3- 39 year old AAM with chest pain, PMH HTN.

oded
Download Presentation

Is He Having The Big One?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Is He Having The Big One? Sirous Partovi, M.D. Department of Emergency Medicine TTUHSC, El Paso

  2. ECG #1- 68 year old with chest pain for 3 days

  3. ECG #2- 66 year old man with 1 hour history of chest pressure

  4. ECG #3- 39 year old AAM with chest pain, PMH HTN

  5. ECG #4 - 62 year old with profuse diaphoresis and vomiting

  6. ECG #5-72 year old male- PMH: CRF,a-fib presents with generalized weakness for 1 hour.

  7. ECG #6- 45 year old female with onset of chest discomfort 2 hours ago – PMH ?Cancer

  8. ECG #7 – 50 year old man with crushing substernal chest pain for 30 minutes

  9. ECG #8- 72 year old female with history of HTN found unconscious

  10. ECG #9- 67 year old man with PMH of MI in respiratory failure due to acute CHF

  11. ECG #10- Chest pain radiating to the jaw in a 41 year old woman

  12. Objectives • Understand the etiology of chest pain • Distinguish between Acute Coronary events requiring thrombolysis and those that do not. • Recognize the more common conditions that may cause a pseudo-infarction pattern on ECG.

  13. Chest Pain • 2% of all ED visits • 10-20% are diagnosed with AMI • 1.7 million admissions to hospitals annually • $5 Billion spent on admitted patients which AMI was subsequently ruled out in

  14. Chest Pain- AMI • 1.1 million cases of AMI annually • 50% present to EDs • 2%-8% rate of misdiagnosis • 11,000 missed diagnosis of MI per year • 20% of money awarded in malpractice cases

  15. Differential Diagnosis of Chest Pain Cardiac • Ischemic • Angina • Unstable angina • AMI • Non-ischemic • Pericarditis • Aortic dissection • Valvular • Myositis

  16. Differential Diagnosis of Chest Pain Non-cardiac • Gastroesophageal Causes • GERD • Esophageal spasm • PUD • Boerhaave’s Syndrome • Cholecystitis

  17. Differential Diagnosis of Chest Pain Non-cardiac • Non-gastroesophageal • Pneumothorax • Pulmonary embolism • Musculoskeletal • Somatoform disorders

  18. Chest Pain-Diagnosis • History and Physical • ECG • Cardiac serum markers

  19. AMI- World Health Organization (WHO) Definition • A combination of two of three characteristics: • Typical symptoms (i.e., ischemic-type chest discomfort) • A rise and fall in serum cardiac markers • Typical ECG pattern involving the development of Q waves

  20. Acute MI - History • 70%-80% present with ischemic type CP • Less than 25% of patients admitted to hospital with ischemic-type CP are diagnosed with AMI • Unusual symptoms for AMI • Elderly • Women • Diabetics

  21. Features of H&P That Increase the Probability of AMI Panju et al, JAMA. 1998;280:1256-1263 History and Physical LR • Chest pain radiating to both arms 7.1 • Third heart sound 3.2 • Hypotension 3.1 • Chest pain radiating to right shoulder 2.9

  22. Likelihood Ratio Positive LR • Odds that a patient with a positive test result has the target disorder Pos LR= Sensitivity/(1-Specificity) Negative LR • Odds that a patient with a negative test result has the target disorder Neg LR= (1-Sensitivity)/Specificity

  23. Historical Features That Decrease the Probability of AMI Panju et al, JAMA. 1998;280:1256-1263 Quality of Chest Pain LR • Pleuritic 0.2 • Sharp or stabbing 0.3 • Positional 0.3 • Reproduced by palpation 0.2-0.4

  24. ECG evolution in Q-wave Myocardial Infarction • Tall peaked T-waves • ST-segment elevation • Appearance ofabnormalQ wave • Decrease of ST-segment elevation with the beginning of T-wave inversion • Isoelectric ST-segment with symmetrical T-wave inversion

  25. Tall T- Waves • The earliest sign of AMI • Due to subendocardial ischemia • Within minutes or hours after the onset of chest pain • Transient • Most ECGs fail to show this pattern

  26. ECG evolution in Q-wave Myocardial Infarction • Tall peaked T-waves • ST-segment elevation • Appearance ofabnormalQ wave • Decrease of ST-segment elevation with the beginning of T-wave inversion • Isoelectric ST-segment with symmetrical T-wave inversion

  27. ST-Segment Elevation • The most common early ECG sign • STE - specificity 91% , sensitivity 46% • Mortality increases with the number of ECG leads showing ST elevation • STE decreases in the first 7-12 hours • STE resolves within 2 weeks in 90% of IWMI, but only in 40% of anterior MI

  28. Reciprocal ST-Segment Depression • Seen in up to 82% • Marked early, 50% resolve within 24 hours • Due to reciprocal electrical alteration • Increases specificity of AMI to 99% • Seen in 72% of IWMI • Indicative of: • Larger AMI • Lower ventricular ejection fraction • Higher mortality

  29. ECG evolution in Q-wave Myocardial Infarction • Tall peaked T-waves • ST-segment elevationrepresents a stage beyond ischemia -i.e. injury • Appearance ofabnormal Q-wave • Decrease of ST-segment elevation with the beginning of T-wave inversion • Isoelectric ST-segment with symmetrical T-wave inversion

  30. Abnormal Q-Waves • Most commonly presents while ST-segment still elevated • 12-20% of Q-waves do not persist • CHF is more common with persistent Q-waves

  31. ECG evolution in Q-wave Myocardial Infarction • Tall peaked T-waves • ST-segment elevation • Appearance ofabnormalQ wave • Decrease of ST-segment elevation with the beginning of T-wave inversion • Isoelectric ST-segment with symmetrical T-wave inversion

  32. ECG evolution in Q-wave Myocardial Infarction • Tall peaked T-waves • ST-segment elevationrepresents a stage beyond ischemia -i.e. injury • Appearance ofabnormal Q wave • Decrease of ST-segment elevation with the beginning of T-wave inversion • Isoelectric ST-segment with symmetrical T-wave inversion

  33. Criteria for Thrombolysis • ST elevation (greater than 1 mm in two or more contiguous leads), time to therapy 12 hours or less, age less than 75 years. • Bundle branch block (obscuring ST-segment analysis) and history suggesting acute MI.

  34. AMI Diagnosis- ECG Factors Influencing ECG Interpretation • Clinical observation of the patient • Knowledge of clinical data • Training and experience of interpreter

  35. AMI Diagnosis- ECG Gjorup et al, J Intern Med. 1992; 231: 407-412 • 16 IM residents read 107 ECGs • Looking for signs indicative of AMI • Disagreement in 70% of the cases

  36. AMI Diagnosis- ECG Willems et al, NEJM. 1991; 325:1767-1773 • 8 cardiologists interpreted 1220 ECGS • High interobserver agreement -  of 0.67 • 125 ECGs read twice • Different diagnosis for 10%-23% of ECGs

  37. AMI Diagnosis- ECG Massel et al. Am Heart J. 2000;140:221-6 • 3 cardiologists - 75 ECGs • 2 occasions (within 7 days) • First reading: Presence or absence of thrombolysis eligibility criteria • Second reading: criterion 1 plus the subjective opinion that the changes represented acute transmural injury

  38. Interobserver variability in thrombolytic therapy eligibility Is there 1 mm ST elevation? Does this represent an AMI? Agreement kappa Agreement kappa Rater 1 vs 2 93.3 86.2 94.7 88.2 Rater 2 vs 3 88.0 75.8 94.7 88.0 Rater 1 vs 3 86.7 72.9 94.7 88.2 Overall 78.2 88.5 AMI Diagnosis- ECG

  39. Errors in AMI • ECG of a patient who is otherwise eligible may be incorrectly interpreted as being nondiagnostic • ST-segment elevation may be erroneously interpreted as suggesting an AMI, resulting in the inappropriate overuse of thrombolysis

  40. Errors in AMI – Missed Diagnosis • ECG of a patient who is otherwise eligible may be incorrectly interpreted as being nondiagnostic • ST-segment elevation may be erroneously interpreted as suggesting an AMI, resulting in the inappropriate overuse of thrombolysis

  41. Errors in AMI - Missed Diagnosis McCarthy et al, Ann Emerg Med.1993;22:5795-82 • Rate of missed AMI among 6 NE hospitals • 1050 patients with AMI • 1.9% misdiagnosed • 25% of the patients with missed AMI had STE of at least 1 mm • Death or severe complications in 25% of pts

  42. Errors in AMI - Missed Diagnosis Pope et al, NEJM 2000;342:1163-70 • 10,689 patients, 10 hospitals (ACI-TIPI trial) • 17% had acute cardiac ischemia (ACI) • 8% AMI • 9% UA • 6% stable angina • 21% other cardiac diagnosis • 55% noncardiac diagnosis

  43. Errors in AMI – Missed Diagnosis Pope et al • Of 894 AMI patients, 19 (2.1%) was missed • 8 (47%) had one of the following ECG readings: LVH, LBBB, BER, pericarditis • 7 (41%) minor ST segment abnormality with <1mm of ST segment deviation • 14 of 19 had NQWMI

  44. Errors in AMI – Missed Diagnosis Brady et al, AEM, April 2001 • 11 ECGs with STE • 45 yo male with HTN, DM and chest pain • 458 EPs

  45. Errors in AMI – Missed Diagnosis Brady et al, AEM, April 2001 • Overall rate of correct

  46. Errors in AMI • ECG of a patient who is otherwise eligible may be incorrectly interpreted as being nondiagnostic • ST-segment elevation may be erroneously interpreted as suggesting an AMI, resulting in the inappropriate overuse of thrombolysis

  47. Errors in AMI - Over Diagnosis Lee et al, Ann Int Med 1989;110:957-62.   • No AMI in 25% of patients with acute chest pain and ST-segment elevation • For every 8 patients appropriately treated with a thrombolytic agent 1 or 2 will be treated unnecessarily

  48. Errors in AMI-Over Diagnosis Sharkey et al, Am J Cardiol 1994;73:550-3 • 93 patients with chest pain receiving thrombolytic therapy, AMI did not occur in 10 (11%) • LVH- 30% • BER- 30% • IVCD- 30%

  49. Impact of Errors • Bleeding consequences • Life-threatening bleed- 0.4% • Moderate bleed- 5% • Not treating an eligible thrombolysis candidate • Financial consequences • Missed AMI is the leading cause of malpractice loss in the ED setting

  50. Causes of ST Segment Elevation Cardiac • Acute myocardial infarction •   Variant (Prinzmetal's) angina •   Acute pericarditis •   Left ventricular aneurysm •   Left ventricular hypertrophy •   Bundle branch blocks •   Benign Early repolarization

More Related