ST elevation myocardial infarction diagnostic criteria: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 20: Line 20:
{{WikiDoc Cardiology Network Infobox}}
{{WikiDoc Cardiology Network Infobox}}
{{CMG}}
{{CMG}}
__TOC__
 
__FORCETOC__


==Overview==
==Overview==

Revision as of 20:05, 1 July 2010

Myocardial infarction
Acute Myocardial infarction; Posterior wall.
Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
ICD-10 I21-I22
ICD-9 410
DiseasesDB 8664
MedlinePlus 000195
eMedicine med/1567  emerg/327 ped/2520

For patient information click here

WikiDoc Resources for ST elevation myocardial infarction diagnostic criteria

Articles

Most recent articles on ST elevation myocardial infarction diagnostic criteria

Most cited articles on ST elevation myocardial infarction diagnostic criteria

Review articles on ST elevation myocardial infarction diagnostic criteria

Articles on ST elevation myocardial infarction diagnostic criteria in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on ST elevation myocardial infarction diagnostic criteria

Images of ST elevation myocardial infarction diagnostic criteria

Photos of ST elevation myocardial infarction diagnostic criteria

Podcasts & MP3s on ST elevation myocardial infarction diagnostic criteria

Videos on ST elevation myocardial infarction diagnostic criteria

Evidence Based Medicine

Cochrane Collaboration on ST elevation myocardial infarction diagnostic criteria

Bandolier on ST elevation myocardial infarction diagnostic criteria

TRIP on ST elevation myocardial infarction diagnostic criteria

Clinical Trials

Ongoing Trials on ST elevation myocardial infarction diagnostic criteria at Clinical Trials.gov

Trial results on ST elevation myocardial infarction diagnostic criteria

Clinical Trials on ST elevation myocardial infarction diagnostic criteria at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on ST elevation myocardial infarction diagnostic criteria

NICE Guidance on ST elevation myocardial infarction diagnostic criteria

NHS PRODIGY Guidance

FDA on ST elevation myocardial infarction diagnostic criteria

CDC on ST elevation myocardial infarction diagnostic criteria

Books

Books on ST elevation myocardial infarction diagnostic criteria

News

ST elevation myocardial infarction diagnostic criteria in the news

Be alerted to news on ST elevation myocardial infarction diagnostic criteria

News trends on ST elevation myocardial infarction diagnostic criteria

Commentary

Blogs on ST elevation myocardial infarction diagnostic criteria

Definitions

Definitions of ST elevation myocardial infarction diagnostic criteria

Patient Resources / Community

Patient resources on ST elevation myocardial infarction diagnostic criteria

Discussion groups on ST elevation myocardial infarction diagnostic criteria

Patient Handouts on ST elevation myocardial infarction diagnostic criteria

Directions to Hospitals Treating ST elevation myocardial infarction diagnostic criteria

Risk calculators and risk factors for ST elevation myocardial infarction diagnostic criteria

Healthcare Provider Resources

Symptoms of ST elevation myocardial infarction diagnostic criteria

Causes & Risk Factors for ST elevation myocardial infarction diagnostic criteria

Diagnostic studies for ST elevation myocardial infarction diagnostic criteria

Treatment of ST elevation myocardial infarction diagnostic criteria

Continuing Medical Education (CME)

CME Programs on ST elevation myocardial infarction diagnostic criteria

International

ST elevation myocardial infarction diagnostic criteria en Espanol

ST elevation myocardial infarction diagnostic criteria en Francais

Business

ST elevation myocardial infarction diagnostic criteria in the Marketplace

Patents on ST elevation myocardial infarction diagnostic criteria

Experimental / Informatics

List of terms related to ST elevation myocardial infarction diagnostic criteria

Cardiology Network

Discuss ST elevation myocardial infarction diagnostic criteria further in the WikiDoc Cardiology Network
Adult Congenital
Biomarkers
Cardiac Rehabilitation
Congestive Heart Failure
CT Angiography
Echocardiography
Electrophysiology
Cardiology General
Genetics
Health Economics
Hypertension
Interventional Cardiology
MRI
Nuclear Cardiology
Peripheral Arterial Disease
Prevention
Public Policy
Pulmonary Embolism
Stable Angina
Valvular Heart Disease
Vascular Medicine

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


Overview

The diagnosis of acute MI is based upon the occurence of:

  1. Clinical symptoms such as substernal chest pain
  2. ECG changes such as ST elevation
  3. A rise in the release of very specific biomarkers into the bloodstream that are normally only found in side the heart muscle cell (the myocyte).

The diagnosis can be confirmed at the time of autopsy or at the time of angiography if a closed artery is seen. A new clinical evidence based diagnostic and classification system has been introduced by Thygesen K, Alpert JS, White HD, et al. and jointly sponsored by the American College of Cardiology (ACC), American Heart Association (AHA), European Society of Cardiology (ESC), and the World Heart Federation (WHF).[1]

Criteria for Diagnosis of Acute Myocardial Infarction

"The term myocardial infarction should be used when there is evidence of myocardial necrosis in a clinical setting consistent with myocardial ischemia. Under these conditions any one of the following criteria meets the diagnosis for acute myocardial infarction". [1]

Below are the criteria quoted from the Thygesen article:

  1. Detection of rise and/or fall of cardiac biomarkers (preferably Troponin) with at least one of the following
    a. Symptoms of ischemia
    b. EKG changes indicative of ischemia as new (ST segment / T wave changes or new left bundle branch block LBBB)
    c. Development of pathological Q waves
    d. Imaging evidence of new viable myocardium or wall motion abnormality
  2. Sudden unexpected cardiac death, including cardiac arrest, often with symptoms suggestive of myocardial ischemia, accompanied by presumably new ST segment elevation, or new LBBB, and/or evidence of fresh thrombus in a coronary artery by angiography and/or at autopsy, if death has occurred before blood samples could be obtained, or at a time before the appearance of cardiac biomarkers in the blood
  3. In patients with normal baseline troponin values, a greater than 3 times increase above the 99th percentile of the upper limit of normal of cardiac biomarkers has been designated as the definition of PCI related myocardial infarction. A subtype related to documented stent thrombosis is recognized.
  4. For patients with CABG surgery; (In patients with normal baseline troponin values) increases of cardiac biomarkers greater than 5 times, (> 5 times the 99th percentile upper limit of normal) and either new pathological Q waves or new LBBB or angiographically evidence of new graft or native vessel occlusion have been designated as defining CABG surgery related myocardial infarction.
  5. Pathological findings of acute myocardial infarction.

Criteria for the Diagnosis of a Prior Myocardial Infarction

If any of the following are present, then a diagnosis of prior myocardial infarction is established:[1]

  • Development of new pathological Q waves with or without symptoms
  • Imaging evidence of a region of loss of viable myocardium that is thinned and fails to contract in the absence of a non ischemic cause.
  • Pathological findings of healed or healing myocardial infarction.

Modern Classification as to the Type of MI

Five types of MI are now recognized and classified as follows: [1]

Type 1: Spontaneous myocardial infarction related to ischemia due to a primary coronary event, such as plaque erosion and/or rupture, fissuring, or dissection.

Type 2: Myocardial infarction secondary to ischemia due to an imbalance of O2 supply and demand, as from coronary spasm or embolism, anemia, arrhythmias, hypertension, or hypotension

Type 3: Sudden unexpected cardiac death, including cardiac arrest, often with symptoms suggesting ischemia with new ST segment elevation; new left bundle branch block; or pathologic or angiographic evidence of fresh coronary thrombus (in the absence of reliable biomarker findings)

Type 4:

a. Myocardial infarction associated with Percutaneous Coronary Interventions (PCI)
b. Myocardial infarction associated with documented stent thrombosis.

Type 5: Myocardial infarction associated with Coronary Artery Bypass Graft surgery

For the main article on cardiac markers see the chapter on cardiac markers. For the main article on the diagnosis of STEMI, see the chapter on Clinical classification of acute myocardial infarction.

Older Classification Schemes as to the Type of MI

There have been several prior classification schemes for characterizing MI:

1. Transmural (necrosis of full thickness of ventricle) vs. non transmural (necrosis of partial thickness of ventricle)

2. Q wave vs. non Q wave: Based upon the development of electrocardiographic Q waves representing electrically inert tissue.

3. ST elevation MI (STEMI) and Non ST elevation myocardial infarction (NSTEMI)

At one time it was thought that Transmural MI and Q wave MI were synonymous. However, not all Q wave MIs are transmural, and not all transmural MIs are associated with Q waves.

Likewise, not all ST elevation MIs go on to cause q waves. Non ST elevation MIs can result in q waves.

Thus, ST elevation MI should not be equated with transmural MI or q wave MI. Likewise, Non ST elevation MI should not be equated with non transmural MI or non q wave MI. These 3 designations reflect three separate but overlapping characterization schemes.

Biomarkers in the Diagnosis of MI

Cardiac markers or cardiac enzymes are proteins that are present in cardiac myocytes that should not be in the bloodstream. When cardiac injury occurs (such as in acute MI), these intracellular proteins are then released into the bloodstream. Along with the patient's history and the electrocardiogram, the release of these enzymes forms the basis of the diagnosis of ST elevation myocardial infarction.

Until the 1980s, the enzymes SGOT and LDH were used to assess cardiac injury. In the early 1980s it was found that disproportional elevation of the MB subtype of the enzyme creatine kinase (CK) was very specific for myocardial injury. More recently, troponin has been used as an even more specific marker of myonecrosis. Current guidelines are generally in favor of troponin sub-units I or T, which are very specific for damage to myocytes.[2] [3][4]

It is important to note that it may take hours for cardiac enzymes to rise following injury to the myocardium, and that cardiac biomarkers may not be elevated on presentation. For this reason, cardiac enzymes and ECGs are checked every 6 to 8 hours over the course of the first 24 hours to "rule out" acute MI. These enzyme measures over the first 24 hours are used to gauge the size of an MI: higer peak levels and a greater area under the curve of enzyme release are associated with larger MIs and poorer prognosis.

"False Positive" Diagnosis of MI: Troponin Elevations That Are Not Due to Thrombotic Coronary Occlusion

It is important to note that cardiac troponins are a marker of all heart muscle damage, not just myocardial infarction. There are other "false positive" causes of troponin elevation that directly or indirectly lead to heart muscle damage can also therefore increase troponin levels:[5] [6]

Sources

  • The 2004 ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction [7]
  • The 2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction [8]

References

  1. 1.0 1.1 1.2 1.3 Thygesen K, Alpert JS, White HD; et al. (2007). "Universal definition of myocardial infarction". Circulation. 116 (22): 2634–53. doi:10.1161/CIRCULATIONAHA.107.187397. PMID 17951284. Unknown parameter |month= ignored (help)
  2. Eisenman A (2006). "Troponin assays for the diagnosis of myocardial infarction and acute coronary syndrome: where do we stand?". Expert Rev Cardiovasc Ther. 4 (4): 509–14. doi:10.1586/14779072.4.4.509. PMID 16918269. Unknown parameter |month= ignored (help)
  3. Aviles RJ, Askari AT, Lindahl B; et al. (2002). "Troponin T levels in patients with acute coronary syndromes, with or without renal dysfunction". N. Engl. J. Med. 346 (26): 2047–52. doi:10.1056/NEJMoa013456. PMID 12087140. Unknown parameter |month= ignored (help)
  4. Summary of "Troponin T levels in patients..." for laymen
  5. Jeremias A, Gibson CM (2005). "Narrative review: alternative causes for elevated cardiac troponin levels when acute coronary syndromes are excluded". Ann. Intern. Med. 142 (9): 786–91. PMID 15867411. Unknown parameter |month= ignored (help)
  6. Ammann P, Pfisterer M, Fehr T, Rickli H. Raised cardiac troponins. BMJ 2004;328:1028-9. PMID 15117768.
  7. Antman EM, Anbe DT, Armstrong PW, Bates ER, Green LA, Hand M, Hochman JS, Krumholz HM, Kushner FG, Lamas GA, Mullany CJ, Ornato JP, Pearle DL, Sloan MA, Smith SC, Alpert JS, Anderson JL, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Halperin JL, Hiratzka LF, Hunt SA, Jacobs AK (2004). "ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1999 Guidelines for the Management of Patients with Acute Myocardial Infarction)". Circulation. 110 (9): e82–292. PMID 15339869. Unknown parameter |month= ignored (help)
  8. Antman EM, Hand M, Armstrong PW; et al. (2008). "2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines: developed in collaboration With the Canadian Cardiovascular Society endorsed by the American Academy of Family Physicians: 2007 Writing Group to Review New Evidence and Update the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction, Writing on Behalf of the 2004 Writing Committee". Circulation. 117 (2): 296–329. doi:10.1161/CIRCULATIONAHA.107.188209. PMID 18071078. Unknown parameter |month= ignored (help)


External links


Template:WikiDoc Sources#redirect:Classification