The Others by benbenzhou

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									   The Others

MK Strecker-McGraw, MD, FACEP
ACS Mimics: Non AMI
Causes of ST-Segment
     Elevation
• ST segment elevation is important EKG
  criterion for dx of AMI
• But, there are other conditions that can
  cause elevation of the ST segments
• Clinical consequences of
  misinterpretation can be deleterious
       DDX ST Segment Elevation
•   Acute Myocardial infarction   •   Left ventricular hypertrophy

•   Acute pericarditis or         •   Prinzmetal angina
    myocarditis
                                  •   Pulmonary embolism
•   Brugada syndrome
                                  •   Miscellaneous causes
•   Cardioversion

•   Early repolarization

•   Hyperkalemia

•   LBBB

•   Left ventricular aneurysm
            Case 1

• 66 year old white male
• ST elevation MI 6 weeks ago
• calls EMS for SOB, diaphoresis
Left Ventricular Aneurysm
• persistence of ST-segment elevation for
  4 weeks or more suggests a ventricular
  aneurysm
• when no previous EKG is available,
  presence of a QS wave in the setting of
  ST segment elevation without T-wave
  inversion is highly suggestive of an
  aneurysm
• reciprocal changes in the inferior leads
  are absent
• Focus on HPI
• Aneurysm should already have Q
  waves

• No reciprocal changes
• Get old EKG’s
• Get serial EKG’s
• Need time and biomarkers/ECHO
            Case 2


• 18 year old white male
• chest pain, SOB
   Acute Pericarditis and
        Myocarditis
• diffuse ST-segment elevations and PR-
  segment depressions
• ST segment has concave morphology
  except aVR, which may be depressed
• when ST elevation in lead II is greater
  in magnitude the the ST elevation in
  lead III, acute pericarditis is the likely
  diagnosis
Pericarditis/Myocardit
• a depressed ST is
                 segment in lead aVL
  associated with an elevated ST
  segment in lead III suggests infarction.
  This relationship is not present in
  pericarditis or early repolarization
• in the limb leads, significant elevations
  > 5mm of the ST segment are
  uncommon with pericarditis, if present,
  suspect AMI
• junction of the QRS and ST segment (J
  point) is clearly discernible
             Case 3


• 88 year old female with chest pain for 2
  hours
 Left Bundle Branch Block
• LBBB septal depolarization is delayed
  and proceeds abnormally from right to
  left
• generate wide and primarily
  monophasic complexes ORS complex >
  0.12 sec
• a QS wave in V1 and a monophasic R
  wave in V6
• large negative QRS complexes in lead
  V1, V2 or V3 are only seen in a few
• key morphologic findings are a wide,
  slurred R wave in the left-sided leads (
  I, aVL, V5 and V6 as well as a QS or an
  rS complex in the right precordial leads
  ( V1 and V2

• absence of customary q wave in lead
  V6 so V6 only demonstrates an initial R
  wave in uncomplicated LBBB
            Case 4

• 40 year old female
• SOB, cough
• fat
   Pulmonary Embolism
• most common EKG dysrhythmia with
  PE is normal sinus, sinus tachycardia
  is less common
• morphology shows ST segment
  depression
• T wave inversions V1-V4 most common
• complete or incomplete RBBB
• S1Q3T3
• P pulmonale ( P wave amplitude > 2.5
  mm in lead II)
•   New T-wave inversions are very common
    in cases of large PEs

• Especially common in anteroseptal leads
• Marriott and other others:
• Simultaneous TWIs in anteroseptal +
    inferior leads is HIGHLY specific for acute
    pulmonary hypertension (= PE)
•   S1Q3T3 is a sign of acute cor pulmonale

•   Any cause of acute cor pulmonale (PE, PTX
    bronchospasm, etc) can result in the S1Q3T3 finding
    on the EKG

•   The ECG is often abnormal in PE, but findings are
    not sensitive, not specific

•   Anterior T wave inversions? Consider the diagnosis
    of massive or sub-massive PE.

•   The ECG is a poor diagnostic tool for PE. The
    greatest utility of the ECG in the patient with
    suspected PE is ruling out other potential life-
    threatening diagnoses such as MI.
             Case 5


• 45 yo male with hypertension
• short of breath, right sided chest pain
Left Ventricular Hypertrophy
• LVH is one of the most common causes
  of ST segment elevation and is
  frequently mistaken for AMI
• in LVH, ST segment and the T wave
  deviate in the opposite direction from
  the major QRS complex
• ST segment elevation has a concave
  contour and is generally limited to leads
  V1-V3
Left Ventricular Hypertrophy

• The deeper the S wave, the greater the
  ST segment elevation
• fully developed LVH commonly shows
  ST segment depression with T wave
  inversion in leads I, aVL, V5 and V6
• ST segment depression is often
  minimal and has a downsloping contour
  (hockey stick)
Left Ventricular Hypertrophy
• T waves are not deep and are
  asymetrically inverted ( slow downward
  phase with fast upward wave)
• significant and/or horizontal ST
  segment depressions and deep
  symmetric inverted T waves are
  atypical and should raise concern for an
  ischemic process
• T wave inversions in leads other than
  the lateral leads suggest myocardial
  ischemia
Left Ventricular Hypertrophy

• Stand alone criteria: R > 11 in aVL
• Sokolow criteria: S V1 + R V5 or V6
  >35
• Cornell criteria:
  S V3 + R aVl > 28 mm men
  S V3 + R aVL > 20 mm women
             Case 6


• 38 yo diabetic female, on dialysis
• short of breath, vomiting
          Hyperkalemia
• Hyperkalemia is defined as a serum K+
  of > 5.5 mEq/L
• mild hyper-K= 5.5-6.5, moderate
  hyperK+ =6.5-8 and severe K+>
  8mEq/L
• The ST segment elevations associated
  with hyperkalemia is uncommon and
  can be diffuse or localized
• unlike typical plateau or upsloping ST
  segment elevation, hyperkalemia often
          Hyperkalemia
• hyperkalemia shortens repolarization
  and the T waves become symmetrically
  tall and peaked with pointed tips
• the base of the T wave narrows ,
  shortening the QT interval ( k+>5.5)
• as K+ increases the QRS widens and
  you can see ST elevation or depression
  (K+>7)
• with further elevation you see flattening
  or disappearance of P waves ( K+>8
  mEq/L)
         Hyperkalemia



• as QRS widens, it merges with the T
  wave resulting in the sine wave pattern
              Case 7

• 18 yo football player
• short of breath at halftime
• had a fight with girlfriend before
  becoming short of breath
     Early Repolarization
• ST segment elevation in the precordial
  leads most commonly V2- V5
• amplitude ranges from 1-4 mm most
  marked in V4 with concave upward
  morphology
• notch at the J point and tall, upright T
  waves
• no reciprocal changes
     Early Repolarization

• can be seen in limb leads (inferior leads
  II, III and aVF with the elevation in II >
  III
• also find reciprocal ST segment
  depression in aVR
• may find a short QT interval and high
  QRS voltages
             Case 8

• 17 yo male, syncope in the hall at
  school
• no past medical history
     Brugada Syndrome
• inherited arrhythmogenic disease
  characterized by a right bundle branch
  like pattern on the EKG
• associated with ST segment elevation
  in leads V1 and V2, less commonly V3
• ST segment is typically downsloping
  and followed by an inverted T wave
• associated with high incidence of
  sudden death among previously healthy
  individuals
     Brugada Syndrome

• believed to be responsible for 4-12% of
  all nonischemic SCD and for
  approximately 20% of SCD in patients
  with structurally normal hearts
• patients are predisposed to episodes of
  ventricular tachycardia
• 3 patterns associated with Brugada
     Brugada Syndrome
•   I: ST segment elevation is triangular (
    coved or convex upward) and the T
    waves can be inverted in leads V1 to V3
•   II: Downward displacement of the ST
    segment lies between the two elevations
    of the segment in leads V1 to V2 (
    concave upward) but does not reach the
    baseline
•   III: Downward displacement of the ST
    segment lies between the 2 elevations of
    the segment in leads V1-V3 and the
    middle part of the ST segment touches

								
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