ECG Basics: Difference between revisions

(Changed redirect target from ECG (Main) to ECG (main))
Tag: Redirect target changed
 
(43 intermediate revisions by 5 users not shown)
Line 1: Line 1:
== General ==
#REDIRECT[[ECG (main)]]
 
*1 small box = 1mm = 0.04 sec = 40 miliseconds
*5 small boxes = 1 big box = 5mm = 0.2 sec = 200 miliseconds
 
== Intervals ==
 
{| border="1" cellspacing="1" cellpadding="1" style="width: 500px;"
|-
| 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
*Deep symmetrical inverted T waves:
#Left ventricle apical hypertrophy
#Raised ICP (e.g.SAH)
#Wellen's (MI)
#Paced rhythm
#BBB's or WPW
#Idiopathic
 
== 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
#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
#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&nbsp;: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
#Triphasic QRS (RSR'), often w/ ST depression & TWI in V1-V3
##V1 must have a positive complex.
#Slurred S in 1 and V6
 
== LBBB ==
#ST depression and TWI are common
#QRS > 0.12 in limb leads
#Leads
##Large and wide R waves — leads I, aVL, V5, and V6
##Small R wave followed by deep S wave —leads II, III, aVF, V1–V3
 
== LAFB ==
#Left axis deviation (-45 or more) w/QRS <0.10s
#Deep S in II, III, and AVF
 
== LPFB ==
#Usually means disease
#Right axis deviation (>110) w/QRS < 0.10s
#Tall R in II, III, AVF
#Exclude other causes (COPD, RVH, Lat MI)
 
 
== Source ==
 
9/09 DONALDSON (adapted from Niemann, Lampe, Pani)
 
[[Category:Cards]] <br/>

Latest revision as of 23:48, 28 November 2019

Redirect to: