St Segmen ecg/dr mahipal

ST Segment ST Segment Elevations in Elevations in ECGECG

DR MAHIPAL REDDYDR MAHIPAL REDDY

NIZAMABAD-INDIANIZAMABAD-INDIA

IntroductionIntroduction

ST segment of the cardiac cycle represents the ST segment of the cardiac cycle represents the period period betweenbetween depolarization and depolarization and repolarization of the left ventriclerepolarization of the left ventricle

In normal state, ST segment is isoelectric relative In normal state, ST segment is isoelectric relative to PR segmentto PR segment


Most ST segment elevationMost ST segment elevation is a result of is a result of non-non-AMI causesAMI causes

Otto LA, Aufderheide TP. Evaluation of ST segment Otto LA, Aufderheide TP. Evaluation of ST segment elevation criteria for the prehospital electrocardiographic elevation criteria for the prehospital electrocardiographic diagnosis fo acute myocardial infarction. Ann Emerg Med diagnosis fo acute myocardial infarction. Ann Emerg Med 1994; 23 (1):17-24.1994; 23 (1):17-24.

Chan TC, Brady WJ, Harrigan RA et al. ECG in Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. 1st ed. Emergency Medicine and Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.Pennsylvania: Elsevier Mosby; 2005.


Of 123 adult Of 123 adult chest pain patientschest pain patients withwith ST ST segment elevation ≥ 1mm,segment elevation ≥ 1mm, 63 patients (51%) did 63 patients (51%) did not have myocardial infarctions. not have myocardial infarctions.

These non-MI were mainly These non-MI were mainly LBBB (21%) and LBBB (21%) and LVH (33%).LVH (33%).

Otto LA, Aufderheide TP. Evaluation of ST segment Otto LA, Aufderheide TP. Evaluation of ST segment elevation criteria for the prehospital electrocardiographic elevation criteria for the prehospital electrocardiographic diagnosis fo acute myocardial infarction. Ann Emerg Med diagnosis fo acute myocardial infarction. Ann Emerg Med 1994; 23 (1):17-24.1994; 23 (1):17-24.

Causes of ST Segment ElevationCauses of ST Segment Elevation

Acute PericarditisAcute Pericarditis Benign Early Benign Early

RepolarizationRepolarization Left Bundle Branch Left Bundle Branch

Block with AMI Block with AMI (Sgarbossa et al’s criteria)(Sgarbossa et al’s criteria)

Left Ventricular Left Ventricular HypertrophyHypertrophy

Left Ventricular Left Ventricular AneurysmAneurysm

Brugada SyndromeBrugada Syndrome HyperkalemiaHyperkalemia HypothermiaHypothermia CNS pathologiesCNS pathologies Prinzmetal AnginaPrinzmetal Angina Post electrical Post electrical

cardioversioncardioversion

Acute Myocardial InfarctionAcute Myocardial Infarction

Initial ST elevation as part of the classic Initial ST elevation as part of the classic evolutionary pattern of acute myocardial evolutionary pattern of acute myocardial infarction was first described by infarction was first described by PardeePardee in 1920 in 1920

Pardee HEB. An electrocardiographic sign of coronary Pardee HEB. An electrocardiographic sign of coronary artery obstruction. Arch Intern Med 1920; 26: 244–57.artery obstruction. Arch Intern Med 1920; 26: 244–57.


The exact reasons AMI produces ST segment The exact reasons AMI produces ST segment elevation are complex and not fully understoodelevation are complex and not fully understood

MI alters MI alters the electrical chargethe electrical charge on the myocardial on the myocardial cell membranes and produce an abnormal cell membranes and produce an abnormal current flowcurrent flow

Goldberger: Clinical Electrocardiography: A Simplified Goldberger: Clinical Electrocardiography: A Simplified Approach, 6th edition, 1999.Approach, 6th edition, 1999.

ST segment elevation measured:ST segment elevation measured: At At J pointJ point – if relative to – if relative to PR segmentPR segment At At 0.06 – 0.08s0.06 – 0.08s from J point – if relative to from J point – if relative to TP TP

segmentsegment


TP segment or PR segment?TP segment or PR segment?

ST Segment Elevation RequirementsST Segment Elevation Requirements

1 mm: I,II,III, aVL, aVF, V5-6

2mm: V1-V4

1Minnesota Code

112TAMI

112TIMI

212GUSTO

211GISSI-2

211GISSI-1

112AHA/ACC

Minimum ST Elevation (mm) Precordial leads

Minimum ST Elevation (mm) Limb leads

Minimum Consecutive Leads

Study

Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.1st ed. Pennsylvania: Elsevier Mosby; 2005.

Minnesota CodeMinnesota Code

The Minnesota code 9-2 requires ≥1 mm ST The Minnesota code 9-2 requires ≥1 mm ST elevation in one or more of leads I, II, III, aVL, elevation in one or more of leads I, II, III, aVL, aVF, V5, V6, or ≥ 2 mm ST elevation in one or aVF, V5, V6, or ≥ 2 mm ST elevation in one or more of leads V1–V4more of leads V1–V4

Menown IB, Mackenzie G, Adgey AA. Optimizing the Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic diagnosis of acute initial 12-lead electrocardiographic diagnosis of acute myocardial infarction. Eur Heart J 2000; 21 (4):275-83.myocardial infarction. Eur Heart J 2000; 21 (4):275-83.

Irrespective of which definition is used, Irrespective of which definition is used, ST ST elevation has poor sensitivity for AMIelevation has poor sensitivity for AMI where where up to 50% of patients exhibit ‘atypical’ changes up to 50% of patients exhibit ‘atypical’ changes at presentation including isolated ST depression, at presentation including isolated ST depression, T inversion or even a normal ECGT inversion or even a normal ECG

Menown IB, Mackenzie G, Adgey AA. Optimizing the Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic diagnosis of acute initial 12-lead electrocardiographic diagnosis of acute myocardial infarction. Eur Heart J 2000; 21 (4):275-83.myocardial infarction. Eur Heart J 2000; 21 (4):275-83.



ST segment elevation MIST segment elevation MI – – persistentpersistent completecomplete occlusion of an artery supplying a occlusion of an artery supplying a significant area of myocardium significant area of myocardium without without adequate collateral circulationadequate collateral circulation

UA/NSTEMI – result from non-occlusive UA/NSTEMI – result from non-occlusive thrombus, small risk area, brief occlusion, or an thrombus, small risk area, brief occlusion, or an occlusion with adequate collateralsocclusion with adequate collaterals

How To Differentiate STE due to How To Differentiate STE due to AMI from Other Causes?AMI from Other Causes?

Magnitude of the elevationMagnitude of the elevation MorphologyMorphology DistributionDistribution Prominent Electrical Forces (Voltage Prominent Electrical Forces (Voltage

Amplitude)Amplitude) QRS widthQRS width Other FeaturesOther Features

Morphology of the ST Morphology of the ST ElevationElevation

Variable Shapes Of ST Segment Variable Shapes Of ST Segment Elevations in AMIElevations in AMI

Goldberger AL. Goldberger: Clinical Electrocardiography: A Simplified Approach. 7th ed: Mosby Elsevier; 2006.

Morphology of STEMorphology of STE

Concave shape STE – non AMI causesConcave shape STE – non AMI causes AMIAMI causes – usually demonstrate causes – usually demonstrate

convex/straight STEconvex/straight STE

J point

Apex of T wave

Concave STEConvex STE

Notching or slurring of J point

Concave STE

Benign Early RepolarizationBenign Early Repolarization

Large amplitude T wave

ECG characteristics:ECG characteristics: STE STE <2 mm<2 mm ConcavityConcavity of initial portion of the ST segment of initial portion of the ST segment NotchingNotching or slurring of the terminal QRS complex or slurring of the terminal QRS complex Symmetrical, concordant Symmetrical, concordant T wave of large amplitudeT wave of large amplitude Widespread or Widespread or diffusediffuse distribution of STE distribution of STE

o Does not demonstrate territorial distributionDoes not demonstrate territorial distribution

Relative temporal Relative temporal stabilitystability

Benign Early RepolarizationBenign Early Repolarization

Distribution Distribution

DistributionDistribution

STE due to AMI usually demonstrate STE due to AMI usually demonstrate regional regional or territorial patternor territorial pattern Examples:Examples: Anterior MI – V3-V4Anterior MI – V3-V4 Septal MI – V2-V3Septal MI – V2-V3 Anteroseptal MI – V1/2 – V4/5Anteroseptal MI – V1/2 – V4/5 Lateral MI – V5/V6Lateral MI – V5/V6 Inferior MI – II, III, aVFInferior MI – II, III, aVF

Diffuse STE – non AMI causes, e.g. pericarditisDiffuse STE – non AMI causes, e.g. pericarditis

PericarditisPericarditis


STE in STE in pericarditispericarditis – – concaveconcave; ; AMIAMI – – obliquely obliquely flat or convexflat or convex

STE in STE in pericarditispericarditis – – diffusediffuse; ; AMI AMI – – territorialterritorial

PR DepressionPR Depression – – pericarditispericarditis; Q in AMI; Q in AMI T inversion in pericarditisT inversion in pericarditis occurs occurs only after only after

ST normalized;ST normalized; T inversion T inversion accompaniesaccompanies STE in AMI (co-exist)STE in AMI (co-exist)

Differentiating ECG Changes of Differentiating ECG Changes of AMI vs PericarditisAMI vs Pericarditis



PR segment depression is usually transient but PR segment depression is usually transient but may be the may be the earliest and most specific signearliest and most specific sign of of acute myopericarditisacute myopericarditis

Baljepally R, Spodick DH. PR-segment deviation as the Baljepally R, Spodick DH. PR-segment deviation as the initial electrocardiographic response in acute pericarditis. initial electrocardiographic response in acute pericarditis. Am J Cardiol 1998; 81 (12):1505-6.Am J Cardiol 1998; 81 (12):1505-6.


Acute Pericarditis – Four Classical Acute Pericarditis – Four Classical StagesStages

First described by First described by Spodick et alSpodick et al

Stage IStage I first few days first few days 2 weeks 2 weeks STE, PR depressionSTE, PR depression

Stage IIStage II last days last days weeks weeks Normalization of STENormalization of STE

Stage IIIStage III after 2-3 weeks, lasts after 2-3 weeks, lasts

several weeksseveral weeks T wave inversionT wave inversion

Stage IVStage IV lasts up to several monthslasts up to several months gradual resolution of T gradual resolution of T

wave changeswave changes

Chan TC, Brady WJ, Pollack M. Electrocardiographic manifestations: acute myopericarditis. J Emerg Chan TC, Brady WJ, Pollack M. Electrocardiographic manifestations: acute myopericarditis. J Emerg Med 1999; 17 (5):865-72.Med 1999; 17 (5):865-72.

Stage 1 PericarditisStage 1 Pericarditis

PR Depression



Both demonstrate initial concavity of upsloping ST Both demonstrate initial concavity of upsloping ST segment/T wavesegment/T wave

PR depression in pericarditis; not in BERPR depression in pericarditis; not in BER ST/T RatioST/T Ratio

ST/T ratio ≥ 0.25 – pericarditis ST/T ratio ≥ 0.25 – pericarditis ST/T ratio < 0.25 – BERST/T ratio < 0.25 – BER

Ginzton LE, Laks MM. The differential diagnosis of acute pericarditis Ginzton LE, Laks MM. The differential diagnosis of acute pericarditis from the normal variant: new electrocardiographic criteria. from the normal variant: new electrocardiographic criteria. Circulation 1982; 65 (5):1004-9.Circulation 1982; 65 (5):1004-9.

ECG Changes of Pericarditis vs ECG Changes of Pericarditis vs Benign Early RepolarizationBenign Early Repolarization

Brugada Syndrome: Brugada Syndrome: ECG patternsECG patterns

RBBBRBBB ST Elevations limited to ST Elevations limited to rightright precordial leads V1 and precordial leads V1 and

V2V2 Saddle shaped or Saddle shaped or coved shapedcoved shaped ST elevation ST elevation First described in 1992 by Brugada and BrugadaFirst described in 1992 by Brugada and Brugada The syndrome has been linked to mutations in the

cardiac sodium-channel gene Amal Mattu, Robert L. Rogers, Hyung Kim, Andrew D. Perron and Amal Mattu, Robert L. Rogers, Hyung Kim, Andrew D. Perron and

William J. Brady. The Brugada Syndrome. The American Journal of William J. Brady. The Brugada Syndrome. The American Journal of Emergency Medicine, Vol. 21, No. 2, March 2003Emergency Medicine, Vol. 21, No. 2, March 2003

ST Elevation morphologies in ST Elevation morphologies in Brugada SyndromeBrugada Syndrome

RBBB with RSR pattern rather than rSR pattern and there is associated STE

QRS WidthQRS Width

Left Bundle Branch BlockLeft Bundle Branch Block

In LBBB, the QRS complex is broad with In LBBB, the QRS complex is broad with negative QS or rS complex in lead V1, and may negative QS or rS complex in lead V1, and may demonstrate STEdemonstrate STE

What if, LBBB co-exist with STEMI?What if, LBBB co-exist with STEMI?


Sgarbossa CriteriaSgarbossa Criteria

Sgarbossa et al. have developed a clinical Sgarbossa et al. have developed a clinical prediction rule to assist in the ECG diagnosis of prediction rule to assist in the ECG diagnosis of AMI in the setting of LBBB using three specific AMI in the setting of LBBB using three specific ECG findingsECG findings

Sgarbossa EB, Pinski SL, Barbagelata A, et al. Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolving acute Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-myocardial infarction in the presence of left bundle-branch block. N Engl J Med 1996; 334:481-7.branch block. N Engl J Med 1996; 334:481-7.


Score 2 points

OR 4.3

ST Elevation ≥ 5 mm and discordant with QRS complex

Score 3 points

OR 6.0

ST Depression ≥ 1 mm in V1, V2, V3

Score 5 points

Odds Ratio (OR) 25.2

ST Elevation ≥ 1 mm and concordant with QRS complex

Odds Ratio: a measure of the degree of association; for example, the odds of exposure among the cases compared with the odds of exposure among the controls (www.cefpas.it/ebm/tools/glossary.htm)

AMI in the presence of LBBBAMI in the presence of LBBB

A total score of 3 or more suggests that the A total score of 3 or more suggests that the patient is likely experiencing an AMI based on patient is likely experiencing an AMI based on the ECG crtieriathe ECG crtieria

With a score less than 3, the ECG diagnosis is With a score less than 3, the ECG diagnosis is less certain requiring additional evaluationless certain requiring additional evaluation



Subsequent publications have suggested that Subsequent publications have suggested that Sgarbossa’s criteria is Sgarbossa’s criteria is less useful than reported,less useful than reported, with with studies demonstrating decreased sensitivity and inter-studies demonstrating decreased sensitivity and inter-rater reliabilityrater reliability

Shlipak MG, Lyons WL, Go AS et al. Should the electrocardiogram Shlipak MG, Lyons WL, Go AS et al. Should the electrocardiogram be used to guide therapy for patients with left bundle-branch block be used to guide therapy for patients with left bundle-branch block and suspected myocardial infarction? Jama 1999; 281 (8):714-9.and suspected myocardial infarction? Jama 1999; 281 (8):714-9.

Edhouse JA, Sakr M, Angus J et al. Suspected myocardial infarction Edhouse JA, Sakr M, Angus J et al. Suspected myocardial infarction and left bundle branch block: electrocardiographic indicators of acute and left bundle branch block: electrocardiographic indicators of acute ischaemia. J Accid Emerg Med 1999; 16 (5):331-5.ischaemia. J Accid Emerg Med 1999; 16 (5):331-5.


Prominent Electrical Prominent Electrical Forces Forces

Left Ventricular HypertrophyLeft Ventricular Hypertrophy

ECG Diagnostic Criteria for LVHECG Diagnostic Criteria for LVH

10011R in aVL> 11mm

10011R1 + SIII>25 mm

9642Cornell Voltage Criteria

SV3+RaVL>28 mm (men), 20mm(women)

10022Sokolow-Lyon Index

SV1 + (RV5 or RV6)>35mm

SpecificitySensitivity

Other Criteria include Romhilt and Estes Point Score System

Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.

The initial upsloping of the elevated ST segment The initial upsloping of the elevated ST segment is frequently is frequently concave in LVH concave in LVH as opposed to as opposed to the more likely flat/convex ST segment the more likely flat/convex ST segment elevation in ACSelevation in ACS

The T wave is usually asymmetrical in LVHasymmetrical in LVHas opposed to the symmetrical T wave seen in coronary ischemia

ECG Changes of Left Ventricular ECG Changes of Left Ventricular Hypertrophy vs AMIHypertrophy vs AMI

ConclusionConclusion

Not all STE are due to STEMINot all STE are due to STEMI ECG remains a good diagnostic tool, but must ECG remains a good diagnostic tool, but must

be correlated with clinical history and physical be correlated with clinical history and physical examinationexamination

Certain characteristics of the ECG changes may Certain characteristics of the ECG changes may aid in the correct diagnosis: morphology, aid in the correct diagnosis: morphology, distribution, associated QRS complexes, voltage distribution, associated QRS complexes, voltage forces, etc.forces, etc.

ReferencesReferences

Wang K, Asinger RW, Marriott HJ. ST-segment Wang K, Asinger RW, Marriott HJ. ST-segment elevation in conditions other than acute elevation in conditions other than acute myocardial infarction. N Engl J Med 2003; 349 myocardial infarction. N Engl J Med 2003; 349 (22):2128-35.(22):2128-35.


ReferencesReferences

Goldberger: Clinical Electrocardiography: A Simplified Goldberger: Clinical Electrocardiography: A Simplified Approach, 6th edition, 1999.Approach, 6th edition, 1999.

William J. Brady, Theodore C. Chan. William J. Brady, Theodore C. Chan. Electrocardiographic Manifestations: Benign Early Electrocardiographic Manifestations: Benign Early Repolarization. The Journal of Emergency Medicine, Repolarization. The Journal of Emergency Medicine, Vol. 17, No. 3, pp. 473–478, 1999Vol. 17, No. 3, pp. 473–478, 1999

Sgarbossa EB, Pinski SL, Barbagelata A, et al. Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolv-ing acute Electrocardiographic diagnosis of evolv-ing acute myocardial infarction in the presence of left bundle-myocardial infarction in the presence of left bundle-branch block. N Engl J Med 1996; 334:481-7.branch block. N Engl J Med 1996; 334:481-7.

St Segmen ecg/dr mahipal

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