(1p) ecg on going

8/16/2019 (1P) ECG on going

http://slidepdf.com/reader/full/1p-ecg-on-going 1/10

Medicine 2016: medicine 2: ECG (Dr. Jing Calibuso)[Category]

Basic Electrocardiography

• A diagnostic exam to help in the diagnosis and management

primarily of cardiac conditions (others: renal, brain ab’n)

• Recording of te electrical acti!ity of te eart

Cellular electrophysiology

• Cardiac cells:

o electrically "olari#ed at resting state

o

mainly negati!ely carged inside$ "ositi!ely carged outsideo carge: %&' milli!olts

Depolarization:

o undamental electrical e!ent of te eart

o ose teir internal negati!ity

o What happens is positive ions go inside the cell, and then it will

depolarize the rest of the cardiac cells, cardiac cells lose theirinternal negativity, it will proceed to transfer to another cell untileverything is depolarized

Repolarization

o Restoration of "olarity (o""osite te direction of de"olari#ation)

o Return of negati!e carge inside te cello ast one to be de"olari#ed is te *rst one to re"olari#ed

• f you put an electrode on one side of a cardiac cell, if the wave

would proceed from here to that

(!) electrode, on "#$ you will

see a positive de%ection towards the electrode, if however the wave

of depolarization is opposite of that the electrode, on "#$ you would

appreciate a negative de%ection&

• f the wave of depolarization start here going to this electrode,

initially it will register a (!) de%ection, at the point where it becomes

perpendicular to the electrode, it will go bac' to isoelectric level, if

wave of depolarization go further, it becomes a negative de%ection,

so the end result you will have a biphasic wave (up and down)

•

ositive de%ection: recording when the electric wave is *WA+- theelectrode

• .egative de%ection: when the electric

wave is going AWA/ from the electrode

• 0iphasic wave: if erpendicular to the

electrode1 e2ual positive and negative

de%ections&

Conduction System o the !eart

Sinus node

o +ain "acema,er of te eart

o -'%''b"m (fastest "acema,er)

o /n0uenced by te 13 (43ym"a546R7

8agal596R)o +ain blood su""ly: left coronary system

and rigt coronary system

"trio#entricular node

o '%-' b"m

o /n0uenced by 13

o +ain blood su""ly: rigt coronary artery and left circum0e;

artery

Electrical conducting cells

o 6ard <iring of te earto Conduct current to te distant regions of te eart

o 1trial conducting system: Bachman$s %undle

o 8entricular conducting system:

!is %undle &et and Right %undles (eft bundles furter

subdi!ided into te ant and "ost fascicles)'ur(in)e

system su""ly te myocardial cells

Myocardial cells

o Contains abundant contractile "roteins actin and myosin

o Contractile unit of te eart

o Current is s"read slo<ly across te entire myocardium causing

te eart to beat at ='%>b"mo 8entricular "acema,er

EC* leads

&im% leads

o Bipolar leads

Consist of 2 electrodes ("ositi!e and negati!e) "laced at 2

di?erent sites Register te di?erence in "otentials bet<een tese 2 sites

o +nipolar leads

+easure te absolute electrical "otential at one site relati!e

to an electrode <it #ero "otential

&im% lead placements

@age 1 of 10




o Red (R): R AE

o Bello< (): AE

o Green (): foot

o lac, (): ust a ground

Bipolar lim% lead

o &ead ,: registers te "otential

bet<een te R arm (%) and arm ()o &ead ,,: registers te "otential bet<een foot () and R arm (%)o &ead ,,,: registers te "otential bet<een foot () and arm (%)

o Eintho#en$s triangle

o "-ial reerence system

• Re"resents te frontal = of

te eart

• &ead ,: reference lead: #ero

degree

• &ead ,,: -'° from lead /

• &ead ,,,: 2'°"ositi!e from lead /

• "verything cloc'wise to lead 3 positive

• #ounter cloc'wise to lead 3 negative

• +epresents 4rontal plane of the heart

"ugmented +nipolar lim% leads

o 1ugmented as muc as >'F

o &ead a.R: records te

"otential of R arm in reference

to te a!erage "otential

bet<een arm foot

• %>'° from lead /

o &ead a.&: records te

"otential of arm in

reference to te a!erage

"otential of R arm foot• %='° from lead /

o &ead a./: records te "otential of

foot in reference to te a!erage

"otential of R arm arm

• &'° from lead /

o "-ial graphic system

&eads .entricular region

, a.& ateral

,, ,,, a./ /nferiora.R Rigt

'recordial leads

o n to" of te cest

o - leads : 8%8-

o 8=H8 are designated as transition #ones7 ere you see more or

less eIual R <a!e and

3 <a!eo Ani"olar leads

re"resenting te coronal

"lane of te earto Can re"resent <ole anterior "ortion

of te eart

• @lacement:

.1: t /C3 R "arasternal border

.2: o""osite 8$ t /C3

"arasternal border .: >t /C3 mid cla!icular line

.: bet<een 82 and 8

.3: >t /C3 anterior a;illary line

.6: >t /C3 mid a;illary line

EC* RE"D,4*

• 3tandardi#ation

• Regularity

• Rytm

• Rate

• 1;is

•/nter!als

3K1D1RD/L1K/:

EC* paper:

o big sIuare 5 > small sIuare

o Big s5uare: 02 sec and

03m.o Small s5uare: 00 sec and

01m.o 3ould co!er 'mm

o Duration e;"ress in seconds

3tandard s"eed: 2>mmHsec

o 6eigtHam"litude e;"ress in milli!olts

3tandard am"litude: 'mmHm8

@age 2 of 10

M so<s te direction ofde"olari#ation so lead is

designated at #ero degrees$anyting belo< it designatedas ()$ abo!e designated as

&eads .entricular region

.17.2 3e"tal

.7. 1nterior

.37.6 ateral




EC* tracing

o ' 8a#e: atrial de"olari#ation

o 9RS 8a#e: !entricular de"olari#ation$ atrial re"olari#ation

9 8a#e: st negati!e de0ection after @

R 8a#e: st "ositi!e de0ection after N

S 8a#e: st negati!e de0ection after R

o 8a#e: !entricular re"olari#ation

REGA1R/KB

• ' 8a#es: distances more li,ely eIual$ may !ary in 'F still

considered normal

• 9RS 8a#es: fairly regular7 measure distance by cali"er

R6BK6+

• 3inus: a""reciate @ <a!e

o @acing is from sinus node

• E.g. Regular sinus rytm

R1KE

• ormal: -'%''b"m

• 6eart 5 >''H(O of small sIuares bHn 2 consecuti!e R <a!es)o large sIuare 5 ='' b"mo 2 large sIuares 5 >' b"mo = large sIuares 5 '' b"mo large sIuares 5 P> b"mo > large sIuares 5 -' b"m

1Q/3

• +ean direction of !ector for

atrial de"olari#ationo R to and sligtly

inferiorlyo Going to lead //: ()

de0ection in @ <a!eo 8: bi"asic @ <a!e

• Direction of !ector for

!entricular de"olari#ationo De"olari#ation of te rest

of te !entricleo Dominated by te left !entricle because of bigger muscle mass

o eft<ard and inferiorly

&ead 1 and a./

o ot u": normal a;is (%='° % ''°)

o ead (Hu") and a8 (%Hdo<n): left a;is de!iation (%='°% %&'°)

o ead (%Hdo<n) and a8(Hu"): rigt a;is de!iation(&'°% '°)

o ot (%Hdo<n): E;treme a;is de!iation (%''° % '°)

/KER813

• ' 8a#e: recording of atrial

de"olari#ationo Duration: not more tan 012

secondso 1m"litude: not more tan 23

milli#olts

• 'R inter#als: +easures te time from

te start of atrial de"olari#ation to te

start of !entricular de"olari#ationo 4ormal: 0127020 sec

• 9RS inter#al: measures te duration of

te !entricular de"olari#ation$ start is N and ends in 3o 4ormal: 0;7010 sec

o Direction of !ector for !entricular de"olari#ation

o 3e"tal de"olari#ation

eft to rigt direction

8: () de0ection

8- (%) de0ection

o De"olari#ation of te rest of !entricle$ dominated by left !entricle

eft<ard and inferiorly

8: (%) de0ection

3 <a!e 8-: () de0ection R <a!e

o R <a!e "rogression

+o!ement from 8 to 8-

8 de"olari#ation

o 3 <a!e

smaller

o 8= and 8: transition #one (eIual and eIual S de0ections)

S segment

o End of 3 and beginning of K <a!e

o +easures te time of te end of te !entricular de"olari#ation to

te start of !entricular re"olari#ation

@age of 10




• < point

o Junction of 3 <a!e and beginning of 3K segment

o 3ould be at te le!el of te @R segment

o asis of 3K ele!ation or de"ression

• 8a#e

o !entricular re"olari#ation

• + 8a#e: comes after K <a!e

o 6t: >%2>F of te K <a!e (usually T.>mm)• 9 inter#al: measures te time from te beginning of te

!entricular de"olari#ation to te end of !entricular re"olari#ationo 4ormal: up to 0 sec

o 8aries <it te eart rate

o ot occu"y more tan 'F of RR inter!al

9c inter#al

o Kacycardial: falsely sort NK inter!al

o radycardia: falsely long NK inter!al

o Bazett$s ormula:

NKc inter!al 5 NKaHsIuare root of RR

Cardiac cycle

• De"olari#ation *rst before mecanical contraction

"R,"& R!=!MS

• arro< NR37 usually su"ra!entricular

• 3inus rytm

o ormal @

Sinus arrhythmia

o ormal in all res"ects e;ce"t

tat it is sligtly irregular 8ariation U 'F

o 1ssociated <it res"iration

/ns"iration: accelerates 6R

E;"iration: slo<s 6R

Sinus %radycardia

o 6eart rate: T-'

o +ay be normal in atlete$ seen in inferior <all +/$ drug induced

(%bloc,ers$ Ca cannels)

Sinus tachycardia

o 6eart rate U''

o Causes: infection$ anemia$ 6$ y"ertyroidism

Sinus arrest>pause

o ailure of te sinus node to *re

o

@@ inter!al during te "auseU2secso 3inus rytm resumes at a @@

inter!al tat is not a multi"le of te basic sinus @@ inter!al

Sinoatrial e-it %loc(

o Second degree

3ome sinus im"ulses fail

to ca"ture te atria /ntermittent absence of @

<a!e Ky"e // (+obit#)

@age of 10




• 3inus node *res but te <a!e of de"olari#ation is

immediately bloc,ed and not transmitted to te

surrounding atrial tissue

Ectopic atrial rhythm

o @ <a!e mor"ology di?erent

from sinus node 1trial rate: T''b"m

@R inter!al UH5 '.2secs

o /n!erted @ <a!es seen in

inferior leads (//$ ///$ a8)

?andering atrial pacema(er

o @ <a!e <it UH5 =

mor"ologieso Rate T''b"m

o +ay a!e !arying @R$ RR$

R@ inter!alo Distinct isoelectric baseline

is "resent

'remature atrial

depolarizationo 1trial "remature beat originated at an atrial site distant from te

sinus nodeo ccurs before te

ne;t antici"ated sinus

<a!eo ormal loo,ing NR3

<a!eo +ay be follo<ed by a "ause

"trial tachycardia

o @ <a!e is di?erent from sinus nodeo = or more beats in succession at an

atrial rate of ''%'b"mo NR3 com"le; resembles normal NR3

during sinus rytmo @R inter!al may be normal or

"rolongedo +ay see in 8

o orm of atrial 0utter

Multiocal atrial tachycardia

o 1trial rate U ''b"m

o @ <a!e <it UH5 = mor"ologies <it distinct isoelectric baselineo 8arying @R$ RR$ R@ inter!al

Supra#entricular tachyardia

o o identi*able @ <a!es$ often buried in

te NR3o arro< NR3

o Regular rytm

o >'%2>'b"m

o +ay be "aro;ysmal (@38K)

o 3een:

ormal earts 3timulants ( co?ee$ alcool)

Coronary artery disease

o Kreatment: carotid massage$ adenosine

"trial @%rillation

o Di?erent circuits are occurring in te atria$ some can "roduce

!entricular res"onseo o /denti*able @ <a!es (*brillation <a!es)

o /rregularly irregular !entricular rytm

o 6eart rate: 6R 5 O of R <a!es in - secs ; '

3lo< !entricular res"onse: 6R T -'b"m

Controlled !entricular res"onse: 6R -'%''b"m Ra"id !entricular res"onse: U''b"m

o 3een:

Coronary artery disease

+itral !al!e disease

6y"ertyroidism

o Kreatment: rate control or rytm control digo;in$ bloc,ers$

amiodarone

"trial Autter

o Circuit in : 3inus node$ tricus"id area$ /8C (cloc,<ise or

countercloc,<ise)o @ <a!es rate: 2>'%=>' b"m

o Ra"id regular atrial undulations (0utter <a!es) 3a<%tooted a""earance

est seen in inferior leads

o o isoelectric area

". <+4C,4"& R!=!MS

• 1rea of 18 node

• NR3 in bet<een su"ra!entricular and !entricular

• '.'%'.2 sec

". )unctional premature

comple-

o @remature NR3 com"le;may be narro<

@age 3 of 10




o /n!erted @ <a!es leads //$ ///$ a8 and u"rigt @ <a!es in leads /

and a8 commonly seeno @ <a!e may "recede te NR3 by less tan '.2 seconds or may

be buried in NR3

• ". )unctional Rhythm

o De"olari#ation

originates from te

18 nodeo o @ <a!e or

"resence of in!erted

@ <a!eo 6R: T-'b"m

o NR3 usually narro<

"ccelerated ". )unctional rhythm

o 3ame <it 18 unctional

o 6RU -'

o o distinct @ <a!e

o arro< NR3

.E4R,C+&"R R!=!MS

• Vide NR3

'remature #entricular depolarization

o NR3 is <ide$ notced or slurred not "receded by a @ <a!e

('U.2secs)o ccurs before te ne;t antici"ated sinus beat

o Asually follo<ed by a com"ensatory "ause

o +ay alternate

<it normal

sinus beat in a

regular "attern @8D :

sinus beat igeminy @8D : = sinus beat Krigeminy

@8D : sinus beats Nuadrigeminy

o &o8n$s grading or '.D

': none

a: T='Hr or THmin

b:5 UHmin

2: U ='Hr

=: multiform$ bigeminy$ trigeminy

a: cou"lets (2 successi!e @8Ds)

b: sal!os (= successi!e @8Ds)

>: R on K "enomenon

can induce !entricular tacycardia

.entricular tachycardia

o Run of tree or more consecuti!e @8Ds

o 6R: 2'%2''b"m

o Regular

o +onomor"ic or "olymor"ic

o 3een in +/$ electrolyte abnormalities$ myocarditis

o +anagement:

Anstable: cardio!ersion or de*brillation

3table: anti%arrytmics (amiodarone)

o Distinct caracteristics:

". dissociation

• 1trial and !entricular rytms are inde"endent of eac

oter/usion %eats

• Results from simultaneous acti!ation of te !entricle from

2 sources

• NR3 com"le; intermediate in mor"ology bHn te NR3

com"le;es of eac source

Capture %eats

• ccurs <en an atrial im"ulse is conducted and

stimulates te !entricle during a !entricular tacycardia

• NR3 com"le; may a""ear similar to tat during te sinusrytm or may a""ear as a fusion beat

9RS concordance

• rom 8%8-$ all NR3 are u"rigt or negati!e

o Monomorphic #entricular .

@age 6 of 10




o 'olymorphic .

Korsades de "ointes (t<isting of

"oints)

• 8K "receded by "rolonged

NK inter!alo @rolonged NK caused by:

congenital$ electrolyte

abnormalites

(y"oW$Ca$+g)

• di?erent forms of NR3

,dio#entricular Rhythm

o Regular !entricular

rytmo NR3 mor"ology

similar to @8Do Rate: T -'b"m

o Xslo< 8KY

o "ccelerated idio#entricular rhythm

Rate -' %''

.entricular @%rillation

o o true NR3 com"le;es$

ECG tracing a""ears

coarse or *neo Caotic and irregular

de0ections of !arying

am"litude and contouro @reterminal e!ent

o K;: de*brillation

"RRES R!=!MS

• @ulseless electrical acti!ity (@E1) or electromecanical dissociation

(E+D)

• 3ee NR3 but no "ulse

"systole

o lat line

o Cec, *rst if leads are "ro"erly "laced

". C4D+C,4 "B4RM"&,,ES

/irst degree ". %loc(

o @rolonged delay in te conduction in

te 18 node or 6is bundleo @rolongation of te @R inter!al

o Can be normal$ myocarditis$ drug%

induced (eg. bloc,ers)

Second degree ". %loc(

o 3ome atrial im"ulses are not able to

"ass troug te 18 node and into

te !entricleso Ky"es:

Mo%itz type , 2nd deg ". %loc( ?enche%ach %loc(

• @rogressi!e lengtening of eac successi!e @R inter!al

until one @ <a!e fails to conduct (dro""ed beat)

• loc, is usually in 18 node

Mo%itz type 2 2nd deg ". %loc(

• 2 or more normal beats <it normal @R inter!al and ten

a @ <a!e tat is not follo<ed by NR3 com"le; (dro""ed

beat)

• loc, belo< te 18 node$ in te 6is bundle

• +ore dangerous tan ty"e /

• +ay lead to =rd degree 18 bloc,

hird degree ". %loc(

o Ke atria are contracting inde"endent of te !entricles

1trial rate -'%''b"m

8entricular rate: ='%>b"m

@age of 10




o E;am"le of 18 dissociation

o Causes: Degenerati!e$ com"lication of +/

"CCESSR= '"!?"=

?olF7'ar(inson7?hite pattern

?'?o ormal @ <a!e

o @R inter!al T'.2 seco /nitial slurring of te NR3 (delta

8a#e) resulting in <ide NR3

(U'.' sec)o 3econdary 3K% K <a!e canges

o 1ccessory "at<ay: Bundle o

Gento Ven stimulus comes from sinus

18 node accessory "at<ay

&o8n7*anong7&e#ine

o ormal @ <a!e

o @R inter!al T'.2 sec

o o delta <a!e

o 1ccessory "at<ay: <ames %undle

,4R".E4R,C+&"R C4D+C,4 "B4RM"&,,ES

Conduction %loc(s

o Bundle Branch Bloc( BBB

loc,s in one or bot !entricular bundle brances

1ssociated re"olari#ation canges (eg. 3K segment

de"ression)

RBBB

o bstruction in te conduction of te R bundle

o R3RZ in 8 and 82

o ,ncomplete

NR3 duration bet<een '.'%'.2 secs

o associated re"olari#ation abnormalities

Does not interfere <it te diagnosis of !entriculary"ertro"y or N <a!e +/

@resent in

• 2F ealty adults

• R !entricular y"ertro"y

• @ost <all +/

o Complete

NR3 inter!al is bet<een U'.2

Re"olari#ation canges in 8 and

82

• Do<n slo""ing 3RZ segment

• K <a!e in!ersion

Vide slurred 3 <a!e in lead /$ 8>

8-

&BBB

o bstruction in te conduction troug te bundle

o NR3 canges in ead /$ a8$ 8> and 8-: mar,ed "rolongation in

te rise of te R <a!es <ic <ill be eiter broad or notced

(R3RZ "attern)

o Ke "resence of "recludes te diagnosis of !entricular

y"ertro"yo Diagnosis of +/ /n C

3K ele!ation UH5 mm concordant to te maor de0ection of

te NR3 3K de"ression UH5 mm 8/$82$or 8=

o /ntra!entricular conduction delay: NR3 duration '.2 secs <itout

any oter criteria for

!EM,B&CGS

• ormal NR3 duration and no 3K segment or K <a!e canges

&et anterior hemi%loc( &"!B

o 1D (%>° to %&'°)

o IR com"le; in leads / and a8 and 3 <a!e in lead ///

o o oter cause for te 1D (eft a;is de!iation)

&et posterior hemi%loc(

o R1D (''° to '°)

o Dee" 3 in lead /o o oter cause for te R1D

@age ; of 10




@ericardial e?usion

• 3us"ect for cardiac tam"onade

3e!ere eart failure

@age 10 of 10

(1p) ecg on going

Documents