Ver el código de «ECG Basics»

==General==
#1 small box = 1mm = 0.04 sec = 40 mili-seconds
#5 small boxes = 1 big box = 5mm = 0.2 sec = 200 mili-seconds

==Intervals==
ECG Seconds mm (sm boxes)

P 0.10 2.5

PR 0.12-0.20 3-5

QRS 0.06-0.10 1.5-2.5

Q <0.04 1

*QT 0.33-0.42 8.25-10.5

QTc <0.44 NA

==Axis==
#axis and ventricular hypertrophy cannot be measured correctly in presence of BBBs....
#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.
#Axis-check lead 1 and AVF..If both are positive then axis is normal .
#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==
#sig Q waves are @ least 1 mm (1 box) wide or @ least 1/3 of the entire QRS amplitude.
#Early Repolarization:
##STE most prominent in lat precord leads (V4-6) but no reciprocal chngs. T waves here usu broad, tall (usu > 5mm) & upright.
##limb leads may also have ste, rarely >2 mm

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

==RAE==
#P amplitude >2.5 mm in II.
#Rarely isolated finding (usu rvh/rad too).
#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.
#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.
#Left atrial hyper.-terminal component is larger than .04 sec.

==LVH==
#Sum of S in V1 or V2 & R in V5 or V6 is >35mm.
#Sum of highest R & deepest S in precord is >45mm
#R wave in V6 > 18mm
#R in AVL of >12mm
#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.

==RVH==
#Dominant R in V1 >7mm (also seen in WPW, RBBB, post MI, & nml var.)
#RSR in V1 w/ QRS < 0.12
#This dx usu also w/ RAE or strain (ST dep w/ twi in V1-V3).
#Less sens. & spec. than LVH, usu nl ecg
#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.
#(note: R :S ratio greater than 1 also in: 1.RBBB 2.WPW type A. 3. Post. Wall MI. 4.kids.)

==RBBB==
#QRS > 0.12 in limb leads (all qrs intervals should be measured in limb leads)
#triphasic QRS (RSR') in ant precord leads (V1-V3), often w/ st dep & twi in these leads
#assoc w/ org heart dz (cant cause rad on own)

#QRS greater than .12.
#slurred s in 1 and V6.
#RSR' in V1 with R' taller than R.
#V1 must have a positive complex.

==LBB==
#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!
#can cause lad, ste seen in ant leads but can call ant mi in rbb!

#duration equals .12sec
#broad monomorphic R waves in 1 and V6 without Q waves.
#broad monomorphic S waves in V1, may have a small r wave.

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

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