ECG Basics: Difference between revisions

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==Axis==
==Axis==
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*If up in leads 1 and AVF then normal axis  
*If up in leads 1 and AVF then normal axis  


#Anterior hemiblock-left axis deviationgreater than-45 to -60. and small q in 1 and avl. RS in 2,3, avf. Intrinsicoid deflection in avl greater than .045.
#posterior hemiblock-right axis deviation and S1Q3.
#Find isoelectric lead. Axis is perpendicular.
#Horizontal axis-find isoeletric chest lead. If shifted to V1 or V2 then counterclockwise rotation. If shifted to V5 or V6 then clockwise rotation.


== Q waves ==
== Q waves ==
 
*Significant if >1 box wide or if is 1/3 of entire QRS amplitude
#sig Q waves are @ least 1 mm (1 box) wide or @ least 1/3 of the entire QRS amplitude.
*Early Repolarization:
#Early Repolarization:
**ST elevation most prominent in lat precord leads (V4-6) but no reciprocal changs
##STE most prominent in lat precord leads (V4-6) but no reciprocal chngs. T waves here usu broad, tall (usu > 5mm) & upright.
**T waves usually broad, tall (>5mm) & upright
##limb leads may also have ste, rarely >2 mm
**Limb leads may also have ST elevation, rarely >2 mm


== T waves ==
== T waves ==
 
*Normally upright in 1, 2, V3-V6
#T waves are normally upright in 1,2,V3 to V6. Negative in AVR.
*Negative in AVR
##if T wave is greater than 2/3 height of R wave it is abnormal.
*If is greater than 2/3 height of R wave then is abnormal


== RAE ==
== RAE ==
 
*Rarely isolated finding (usually RVH/RAD also)
#P amplitude >2.5 mm in II.
*P amplitude >2.5mm in II
#Rarely isolated finding (usu rvh/rad too).
*Large biphasic p wave in V1
#large diphasic p wave in V1. Right atrial hyper.-initial component is larger in V1 than V6 :tall p wave, bigger than 2.5 boxes in limb leads.
*Right atrial hyper.-initial component is larger in V1 than V6
#p-mitrale-m notched p wave in leads 1 and 2. Greater than .12 seconds.
#p-mitrale-m notched p wave in leads 1 and 2. Greater than .12 seconds.


== LAE ==
== LAE ==
 
*Biphasic P in V1 w/ wide, deep terminal component, >1mm depth & wide
#Biphasic P in V1 w/ wide, deep terminal component, >1mm depth & wide.
#Left atrial hyper.-terminal component is larger than .04 sec.
#Left atrial hyper.-terminal component is larger than .04 sec.


== LVH ==
== LVH ==
 
#Sum of S in V1 or V2 & R in V5 or V6 is >35mm
#Sum of S in V1 or V2 & R in V5 or V6 is >35mm.
#Sum of highest R & deepest S in precord is >45mm
#Sum of highest R & deepest S in precord is >45mm
#R wave in V6 > 18mm
#R wave in V6 > 18mm
#R in AVL of >12mm
#R in AVL of >12mm
#L precordial leads may show ST depression & twi= LV strain pattern
#L precordial leads may show ST depression & TWI = LV strain pattern
#LVH-s wave in V1 or V2 (biggest) plus R in V5 or V6 (biggest) is greater than 35mm. LAD-with slightly wide QRS. Or r in avl greater than 11mm, r in 1 is greater than 12mm, or R in AVf is greater than 20mm.
#LAD-with slightly wide QRS. Or r in avl greater than 11mm, r in 1 is greater than 12mm, or R in AVf is greater than 20mm


== RVH ==
== RVH ==
 
#Dominant R in V1 >7mm (also seen in WPW, RBBB, post MI, & nml var)
#Dominant R in V1 >7mm (also seen in WPW, RBBB, post MI, & nml var.)
#RSR in V1 w/ QRS < 0.12
#RSR in V1 w/ QRS < 0.12
#This dx usu also w/ RAE or strain (ST dep w/ twi in V1-V3).
#This dx usu also w/ RAE or strain (ST dep w/ twi in V1-V3).
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== RBBB ==
== RBBB ==
 
#QRS > 0.12 in limb leads
#QRS > 0.12 in limb leads (all qrs intervals should be measured in limb leads)
#Triphasic QRS (RSR'), often w/ ST depression & TWI in V1-V3
#triphasic QRS (RSR') in ant precord leads (V1-V3), often w/ st dep & twi in these leads
##V1 must have a positive complex.
#assoc w/ org heart dz (cant cause rad on own)
#Slurred S in 1 and V6
 
#QRS greater than .12.
#slurred s in 1 and V6.
#RSR' in V1 with R' taller than R.
#V1 must have a positive complex.


== LBBB ==
== LBBB ==
#ST depression and TWI are common
#QRS > 0.12 in limb leads
#Leads
##V1 - rS complex
##I, aVL, V5-6: RsR' without Q waves


#QRS > 0.12 in limb leads, w/ lg, broad , notched or slurred R waves in lat precord leads (V5-V6) & lead I & avL, the st seg is usu depressed & twi in these leads!
== LAFB ==
#can cause lad, ste seen in ant leads but can call ant mi in rbb!
#Left axis deviation (-45 or more) w/QRS <0.10s
#Deep S in II, III, and AVF


#duration equals .12sec
== LPFB ==
#broad monomorphic R waves in 1 and V6 without Q waves.
#Usually means disease
#broad monomorphic S waves in V1, may have a small r wave.
#Right axis deviation (>110) w/QRS < 0.10s
#Tall R in II, III, AVF
#Exclude other causes (COPD, RVH, Lat MI)


== LASH ==
(caused by CAD, valv. dis., cong. dis., cardiomyop., myocard.)
#Axis < -45 (L axis) w/QRS <0.10s
#deep S in II, III, and AVF
#exclude other cause of L axis (habitus, Inf. MI, hyperK, Vent. pre-excitation)
== L Post Inf Hemiblock ==
(USU. organic heart dis.)
#R axis (>110) w/ QRS < 0.10s
#R waves in II, III, AVF.
#Exclude other causes (COPD, RVH, Lat MI)
#(-w/ combined blocks cons. pacing only if sxs w/ bradyarrhythmias)


== Source ==
== Source ==


9/09 DONALDSON (adapted from Niemann, Lampe, Pani)
9/09 DONALDSON (adapted from Niemann, Lampe, Pani)
<br/><br/>


[[Category:Cards]] <br/>
[[Category:Cards]] <br/>

Revision as of 01:35, 8 April 2011

General

  • 1 small box = 1mm = 0.04 sec = 40 miliseconds
  • 5 small boxes = 1 big box = 5mm = 0.2 sec = 200 miliseconds

Intervals

Interval Time (s) boxes
PR 0.12 - 0.20 3-5
QRS .06 - 0.10 1.5-2.5
QTc <0.44 N/A


Axis

  • Cannot be measured if BBBs are present
  • If up in leads 1 and AVF then normal axis


Q waves

  • Significant if >1 box wide or if is 1/3 of entire QRS amplitude
  • Early Repolarization:
    • ST elevation most prominent in lat precord leads (V4-6) but no reciprocal changs
    • T waves usually broad, tall (>5mm) & upright
    • Limb leads may also have ST elevation, rarely >2 mm

T waves

  • Normally upright in 1, 2, V3-V6
  • Negative in AVR
  • If is greater than 2/3 height of R wave then is abnormal

RAE

  • Rarely isolated finding (usually RVH/RAD also)
  • P amplitude >2.5mm in II
  • Large biphasic p wave in V1
  • Right atrial hyper.-initial component is larger in V1 than V6
  1. p-mitrale-m notched p wave in leads 1 and 2. Greater than .12 seconds.

LAE

  • Biphasic P in V1 w/ wide, deep terminal component, >1mm depth & wide
  1. Left atrial hyper.-terminal component is larger than .04 sec.

LVH

  1. Sum of S in V1 or V2 & R in V5 or V6 is >35mm
  2. Sum of highest R & deepest S in precord is >45mm
  3. R wave in V6 > 18mm
  4. R in AVL of >12mm
  5. L precordial leads may show ST depression & TWI = LV strain pattern
  6. LAD-with slightly wide QRS. Or r in avl greater than 11mm, r in 1 is greater than 12mm, or R in AVf is greater than 20mm

RVH

  1. Dominant R in V1 >7mm (also seen in WPW, RBBB, post MI, & nml var)
  2. RSR in V1 w/ QRS < 0.12
  3. This dx usu also w/ RAE or strain (ST dep w/ twi in V1-V3).
  4. Less sens. & spec. than LVH, usu nl ecg
  5. RVH-R wave greater than S in V1, but gets progressively smaller from V1 to V6. S wave persists in V5 and V6. RAD with slightly wide QRS.
  6. (note: R :S ratio greater than 1 also in: 1.RBBB 2.WPW type A. 3. Post. Wall MI. 4.kids.)

RBBB

  1. QRS > 0.12 in limb leads
  2. Triphasic QRS (RSR'), often w/ ST depression & TWI in V1-V3
    1. V1 must have a positive complex.
  3. Slurred S in 1 and V6

LBBB

  1. ST depression and TWI are common
  2. QRS > 0.12 in limb leads
  3. Leads
    1. V1 - rS complex
    2. I, aVL, V5-6: RsR' without Q waves

LAFB

  1. Left axis deviation (-45 or more) w/QRS <0.10s
  2. Deep S in II, III, and AVF

LPFB

  1. Usually means disease
  2. Right axis deviation (>110) w/QRS < 0.10s
  3. Tall R in II, III, AVF
  4. Exclude other causes (COPD, RVH, Lat MI)


Source

9/09 DONALDSON (adapted from Niemann, Lampe, Pani)

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