EKGRefreshand Practice
Normal SinusRhythm
.
r
Rate:
Rhythrn:
o Pwaves:
o PR interval:
r QRS:
60 - 100beatsperminute
Atrial - Regular
Ventricular- Regular
Uniform in appearance
Upright w/ normal shape
OnePrecedingeachQRS
Nor morethan.10 second
0.12- 0.20second
0.10secondor less
P-Waves:
Shouldbe no morethan 2.5 mm in height,andno morethan .10 secondin width
PRInterval:
Includesthe p-waveasit leavesthe baselineandendsat the betinningofthe QRScomplex
QRSComplex:
Measuredfrom the beginningof the QRS complex(asthe first wave leavesthe baseline)to the end of
the eRS complex(whenthelast wave beginsto level out into the ST segment).The end of the QRS
complexis calledthe J-Point'
Normally positive in lead II
ST Segment:
Beginswith the endof the QRS complexandendswith the onsetof the T-wave. Normally flat.
Coisideredelevatedif it is abovethe baselineanddepressedif it is below the baseline. An elevatedST
segrnentis a sign of myocardialinfarct.
T-Wave:
Beginsasthe deflectiongraduallyslopesupwardfrom the ST segmentand endswhenthe waveform
retumsto baseline. Shouldbe positive in a LeadII.
Analyzing a Rhythm StriP
o
o
o
o
o
o
What is the rate?
Is it regularor irregular?
If irregular,is therea pattem of irregularity?
Are thereP-waves?...are they all the same?
If so, is the P-R interval of normal length andarethey all the same?
Is thereonly oneP-Wavefor everyQRS complex?
Rhythm
Normal Sinus
Rhythm (NSR)
Sinus
Bradvcardia
Sinua
Tachycardia
Regularity
Regular
Regular
Regular
Rate
P Waves
QRS Complex
60 to 100
Positive; Rounded;Normal PR
Interval; One P wave for each
QRS complex
Narrow
Lessthan60
Positive;Rounded;Normal PR
Interval; One P wave for each
QRS complex
Narrow
100to 170
Positive;Rounded;NormalPR
Interval;OneP wavefor each
QRScomplex
Narrow
Rhvthm
Supraventricular
Tachycardia
(svr)
PrematureAtrial
Contraction
(PAC)
Sinus
Anhythmia
Rate
P Waves
QRS Complex
Regular
Over170
Not visible,thoughmaybe
presentburriedin QRScomplex
or T waves
Narrow
Regular with
Isolated
Anomalv
That of
Underlying
Rhythm
Positive; Rounded;Normal PR
Interval; One P wave for each
QRS Complex
Narrow
60 to 100
Positive;Rounded;NormalPR
Interval;OneP wavefor each
QRSComplex
Narrow
Regularity
Irregular
Rate
P Waves
QRS Complex
60 to 100
Positive; Rounded;Normal PR
Interval; May seeone nonconducting P before pause
Narrow
Regular or
Irregular
Atrial: 250-400: Positive; Peakedor "Sawtooth"
Ventricular Appearanceto Baseline;Unable
to measurePR Interval
usuallv60-100
Narrow
Irregular
Atrial: No
coordinated
None; Wavy deflectionsaffecting
systole;
baselineas atria quiver
Ventricular
usuallv60-100
Narrow
Rhythm
Regularity
SinusBlockor
SinusArrest
Regular with
SuddenPause
Atrial Flutter
Atrial
Fibrillation
Rhythm
Regularity
Rate
P Waves
QRS Complex
Narrow
Junctional
Rhvthm
Regular
40 to 60
lnverted;May occurbefore/after
ORScomplexor be hidden
Accelerated
Junctional
Regular
60 to 100
Inverted;May occurbefore/after
QRScomplexor be hidden
Narrow
Junctional
Tachvcardia
Regular
Morethan 100
Inverted; May occur before/after
QRS complex or be hidden
Narrow
Rhythm
Premafure
Junctional
Contraction
(PJC)
1' AV Block
2' AV Block,
Mobitz I
(Wenckebach)
Regularity
Rate
P Waves
QRS Complex
Usually
Regular with
Isolated
Anomaly
That of
Underlying
Rhythm
That of Underlying Rhythm; PJC
will have Inverted or hidden P
wave
Narrow
Regular
Regularly
Irregular
Thatof
Positive; Rounded;PR Interval
Underlying
more that0.20sec; One P wave
Rhythm;Usually
for eachQRS Complex
60 to 100
Narrow
Positive;Rounded;PR Interval
WNL at first but lengthens
progressively
until P doesnot
conductto QRS
Narrow
Usually60 to
100,May be
Bradycardic
Rhythm
Regularity
Rate
P Waves
QRS Complex
2" AV Block,
Mobitz II
Usually
Regular,May
be Iregular
Atrial: Varies,
Ventricular:
UsuallyLess
Than60
Positive;Rounded;PR Interval
for conductingbeatsis always
WNL; More than I P wavefor
eachQRSComplex
UsuallyNarrow
Atrial and
Atrial: 60 to
3' AV Block
Ventricular
100,
(CompleteHeart
Regularbut not Ventricular:
Block)
Corresponding Usuallv20-40
Positive; Rounded;Unable to
MeasurePR Interval; P:QRS
Ratio variable; P waves may be
hidden in QRS or T waves
TypicallyWidened
Thatof
Underlying
Rhvthm
Positive; Rounded;Normal PR
Interval; One P wave for each
QRS Complex
Borderline
Wide:0.10
0.14sec;Usually
Notched(QRR'S)
Bundle Branch
Block
That of
Underlying
Rhrrthm
Rhythm
Regularity
Rate
P Waves
QRS Complex
Idioventricular
Rhythm GVR)
Regular
20 to 40
Absent
Wide
IVR
Accelerated
Regular
40 to 100
Absent
Wide
L
Premature
Ventricular
Conntraction
(PVC)
Thatof
Underlying
Rhythmwith
Isolated
Anomaly
Thatof
Underlying
Rhythm
Thatof Underlying
Rhythm;PVC Wide
andMay Have
That of Underlying Rhythm; No P
OppositeDeflection
Wave PreceedinePVC
from Underlying
Rhrrthm
Rhythm
Regularity
Rate
P Waves
QRS Complex
Wide;QRSAdjacent
to QRSor Only T
UsuallyAbsent;If PresentWill
WavesVisible
Not Correlatewith QRSComplex
MaskineBaseline
Ventricular
Tachvcardia
Regular
100to 250
Ventricular
Fibrillation
Irregular
Zero
No CoordinatedSystole;Wavy
Deflections Affecting Baseline as
Ventrical Quiver
Absent
Zero
Lack of ElectricalActivity;
BaselineUsuallyFlat or Nearly
Flat (Mild Deflections
Will Be
LessThan2mm in Height)
Absent
Asystole
None