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ECG MADE VERY EASY FOR MEDICAL STUDENTS AND DOCTORS TO HELP PATIENTS. DR BASHIR ASSOCIATE PROFESSOR MEDICINE PRESENTLY WORKING IN MALAYSIA CHINKIPORA SOPORE KASHMIR [email protected]

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Ecg basics
ECG BASICS

By Dr Bashir Ahmed DarChinkipora Sopore KashmirAssociate Professor MedicineEmail [email protected]


  • From Right to Left

  • Dr.Smitha associate prof gynae

  • Dr Bashir associate professor Medicine

  • Dr Udaman neurologist

  • Dr Patnaik HOD ortho

  • Dr Tin swe aye paeds


  • From RT to Lt

  • Professor Dr Datuk rajagopal N

  • Dr Bashir associate professor medicine

  • Dr Urala HOD gynae

  • Dr Nagi reddy tamma HOD-opthomology

  • Dr Setharamarao Prof ortho


Electrography made easy
ELECTROGRAPHY MADE EASY

  • ULTIMATE AIM TO HELP PATIENTS



Limb and chest leads
Limb and chest leads

  • When an ECG is taken we put 4 limb leads or electrodes with different colour codes on upper and lower limbs one each at wrists and ankles by applying some jelly for close contact.

  • We also put six chest leads at specific areas over the chest

  • So in reality we see only 10 chest leads.


Position of limb and chest leads
Position of limb and chest leads

Four limb leads

Six chest leads

V1- 4th intercostal space to the right of sternum

V2- 4th intercostal space to the left of sternum

V3- halfway between V2 and V4

V4- 5th intercostal space in the left mid-clavicular line

V5- 5th intercostal space in the left anterior axillary line

V6- 5th intercostal space in the left mid axillary line


Horizontal plane the six chest leads

LA

LV

RA

RV

V4

V1

V2

V2

V3

V3

V5

V5

V6

V6

V1

V4

Horizontal plane - the six chest leads

6.5



Ecg paper dimensions
ECG Paper: Dimensions

5 mm

1 mm

Voltage

~Mass

0.1 mV

0.04 sec

0.2 sec

Speed = rate


Ecg paper and timing
ECG paper and timing

  • ECG paper speed = 25mm/sec

  • Voltage calibration 1 mV = 1cm

  • ECG paper - standard calibrations

    • each small square = 1mm

    • each large square = 5mm

  • Timings

    • 1 small square = 0.04sec

    • 1 large square = 0.2sec

    • 25 small squares = 1sec

    • 5 large squares = 1sec



Ecg paper
ECG paper leads are connected to a connector and then to ECG machine.

1 Small square = 0.04 second

1 Large square = 0.2 second

5 Large squares = 1 second

Time

2 Large squares = 1 cm

6.1



Standardisation ecg amplitude scale
STANDARDISATION ECG amplitude scale standardization is properly done.

Normal amplitude

10 mm/mV

Half amplitude

5 mm/mV

Double amplitude

20 mm/mV


Ecg waves
ECG WAVES standardization is properly done.

  • You will see then base line or isoelectric line that is in line with P-Q interval and beginning of S-T segment.

  • From this line first positive deflection will arise as P wave then other waves as shown in next slide.

  • Small negative deflections Q wave and S wave also arise from this line.


Ecg waves1
ECG WAVES standardization is properly done.


The normal ecg
The Normal ECG standardization is properly done.

Normal Intervals:

PR 0.12-0.20s

QRS duration <0.12s

QTc 0.33-0.43s


Simplified normal position of leads on ecg graph
Simplified normal Position of leads on ECG graph standardization is properly done.

  • Lead 1# upward PQRS

  • Lead 2# upward PQRS

  • Lead 3# upward PQRS

  • Lead AVR#downward or negative PQRS

  • Lead AVL# upward PQRS

  • Lead AVF# upwards PQRS


Simplified normal position of leads on ecg graph1
Simplified normal Position of leads on ECG graph standardization is properly done.

  • Chest lead V1# negative or downward PQRS

  • Chest leads V2-V3-V4-V5-V6 all are upright from base line .The R wave slowly increasing in height from V1 to V6.

  • So in normal ECG you see only AVR and V1 as negative or downward defelections as shown in next slide.


Normal ecg
Normal ECG standardization is properly done.

Slide 13


NSR standardization is properly done.


P wave
P-wave standardization is properly done.

  • Normal P wave length from beginning of P wave to end of P wave is 2 and a half small square.

  • Height of P wave from base line or isoelectric line is also 2 and a half small square.


P wave1

Normal values standardization is properly done.

up in all leads except AVR.

Duration. < 2.5 mm.

Amplitude.

< 2.5 mm.

Abnormalities

1. Inverted P-wave

Junctional rhythm.

2.Wide P-wave(P- mitrale)

LAE

3.Peaked P-wave (P-pulmonale)

RAE

4. Saw-tooth appearance

Atrial flutter

5. Absent normal P wave

Atrial fibrillation

P-wave



Shape of p wave
Shape of P wave half small square

  • The upward limb and downward limbs of P wave are equal.

  • Summit or apex of P wave is slightly rounded.


P pulmonale p mitrale
P pulmonale & P mitrale half small square

  • P pulmonale-Summit or apex of P wave becomes arrow like pointed or pyramid shape,the height also becomes more than two small squares from base line.

  • P waves best seen in lead 2 and V1.


P pulmonale p mitrale1
P pulmonale & P mitrale half small square

  • P mitrale- the apex or summit of p wave may become notched .the notch should be at least more than one small square.

  • Duration of P becomes more than two and a half small squares.


Slide 14 half small square


Slide 16 half small square


Left atrial enlargement
Left Atrial Enlargement half small square

Criteria

P wave duration in II >than 2 and half small squares with notched p wave

or

Negative component of biphasic P wave in V1≥ 1 “small box” in area


Right atrial enlargement
Right Atrial Enlargement half small square

Criteria

P wave height in II >2 and half small squares and are also tall and peaked.

or

Positive component of biphasic P wave in V1 > 1 “small box” in area


Slide 15 half small square


Atrial fibrillation
Atrial fibrillation half small square

  • P waves thrown into number of small abnormal P waves before each QRS complex

  • The duration of R-R interval varies

  • The amplitude of R-R varies

  • Abnormal P waves don’t resemble one another.


Slide 41 half small square


Atrial flutter
Atrial flutter half small square

  • The P waves thrown into number of abnormal P waves before each QRS complex.

  • But these abnormal P waves almost resemble one another and are more prominent like saw tooth appearance.


Slide 40 half small square


Junctional rhythm
Junctional rhythm half small square

  • In Junctional rhythm the P waves may be absent or inverted.in next slide u can see these inverted P waves.


Slide 43 half small square


Paroxysmal atrial tachycardia
Paroxysmal atrial tachycardia half small square

  • The P and T waves you cant make out separately

  • The P and T waves are merged in one

  • The R-R intervals do not vary but remain constant and same.

  • The heart rate being very high around 150 and higher.


Slide 39 half small square


Normal p r interval
NORMAL P-R INTERVAL half small square

  • PR interval time 0.12 seconds to 0.2 seconds.

  • That is three small squares to five small squares.


Pr interval

Definition: half small square the time interval between beginning of P-wave to beginning of QRS complex.

Normal PR interval

3-5mm or 3-5 small squares on ECG graph (0.12-0.2 sec)

Abnormalities

1. Short PR interval

WPW syndrome

2. Long PR interval

First degree heart block

PR interval


Short p r interval
Short P-R interval half small square

  • Short P-R interval seen in WPW syndrome or pre- excitation syndrome or LG syndrome

  • P-R interval is less than three small squares.

  • The beginning of R wave slopes gradually up and is slightly widened called Delta wave.

  • There may be S-T changes also like ST depression and T wave inversion.


Slide 17 half small square


Lengthening of p r interval
Lengthening of P-R interval half small square

  • Occurs in first degree heart block.

  • The P-R interval is more than 5 small squares or > than 0.2 seconds.

  • This you will see in all leads and is same fixed lengthening .


Slide 44 half small square


Q waves
Q WAVES half small square

  • Q waves <0.04 second.

  • That’s is less than one small square duration.

  • Height <25% or < 1/4 of R wave height.


Normal q wave
Normal Q wave half small square


Abnormal q waves
Abnormal Q waves half small square

  • The duration or width of Q waves becomes more than one small square on ECG graph.

  • The depth of Q wave becomes more than 25% of R wave.

  • The above changes comprise pathological Q wave and happens commonly in myocardial infarction and septal hypertrophy.


Q wave in mi
Q wave in MI half small square


Q wave in septal hypertrophy
Q wave in septal hypertrophy half small square


Qrs complex
QRS COMPLEX half small square

  • QRS duration <0.11 s

  • That is less than almost three small squares

  • Some books write 2 and a half small squares.

  • Height of R wave is (V1-V6) >8 mm some say >10 mm chest leads (in at least one of chest leads).


Qrs complex1

Normal values half small square

Duration: < 2.5 mm.

Morphology:progression from Short R and deep S (r/s) in V1 to tall R and short S in V6 with small Q in V5-6.

Abnormalities:

1. Wide QRS complex

Bundle branch block.

Ventricular rhythm.

2. Tall R in V1

RVH.

RBBB.

Posterior MI.

WPW syndrome.

3. abnormal Q wave

[ > 25% of R wave]

MI.

Hypertrophic cardiomyopathy.

Normal variant.

QRS complex


Small voltage qrs
Small voltage QRS half small square

  • Defined as < 5 mm peak-to-peak in all limb leads or <10 mm in precordial chest leads.

  • causes — pulmonary disease, hypothyroidism, obesity, cardiomyopathy.

  • Acute causes — pleural and/or pericardial effusions


Normal upward progression of r wave from v1 to v6
Normal upward progression of R wave from V1 to V6 half small square

V6

V5

V4

V3

V2

V1

The R wave in the precordial leads must grow from V1 to at least V4


J point
J point half small square

  • The term J point means Junctional point at the end of S wave between S wave and beginning of S-T segment.


ST half small square

Q

S

J point


L v h voltage criteria
L V H-Voltage Criteria half small square

In adult with normal chest wall

SV1+RV5 >35 mm

or

SV1 >20 mm

or

RV6 >20 mm


Left ventricular hypertrophy voltage criteria
Left ventricular hypertrophy-Voltage Criteria half small square

  • Count small squares of downward R wave in V1 plus small squares of R wave in V5 .

  • If it comes to more than 35 small squares then it is suggestive of LVH.


Left ventricular hypertrophy
LEFT VENTRICULAR HYPERTROPHY half small square


Right ventricular hypertrophy
Right ventricular hypertrophy half small square

  • Normally you see R wave is downward deflection in V1.but if you see upward R wave in V1 then it is suggestive of RVH etc.


Dominant or upward r wave in v1
Dominant or upward R wave in V1 half small square

  • Causes

  • RBBB

  • Chronic lung disease, PEPosterior MIWPW Type ADextrocardiaDuchenne muscular dystrophy


Right ventricular hypertrophy1
Right Ventricular Hypertrophy half small square

  • WILL SHOW AS

  • Right axis deviation (RAD)

  • Precordial leads

  • In V1, R wave > S wave

  • In V6, S wave > R wave

  • Usual manifestation is pulmonary disease or

  • congenital heart disease



Right ventricular hypertrophy3
Right ventricular hypertrophy half small square

  • Right ventricular hypertrophy (RVH) increases the height of the R wave in V1. And R wave in V1 greater than 7 boxes in height, or larger than the S wave, is suspicious for RVH. Other findings are necessary to confirm the ECG diagnosis.


Right ventricular hypertrophy4
Right Ventricular Hypertrophy half small square

  • Other findings in RVH include right axis deviation, taller R waves in the right precordial leads (V1-V3), and deeper S waves in the left precordial (V4-V6). The T wave is inverted in V1 (and often in V2).


Right ventricular hypertrophy5
Right Ventricular Hypertrophy half small square

  • True posterior infarction may also cause a tall R wave in V1, but the T wave is usually upright, and there is usually some evidence of inferior infarction (ST-T changes or Qs in II, III, and F).


Right ventricular hypertrophy6
Right Ventricular Hypertrophy half small square

  • A large R wave in V1, when not accompanied by evidence of infarction, nor by evidence of RVH (right axis, inverted T wave in V1), may be benign “counter-clockwise rotation of the heart.” This can be seen with abnormal chest shape.


Right ventricular hypertrophy7
Right Ventricular Hypertrophy half small square

Although there is no widely accepted criteria for detecting the presence of RVH, any combination of the following EKG features is suggestive of its presence:

  • Tall R wave in V1

  • Right axis deviation

  • Right atrial enlargement

  • Down sloping ST depressions in V1-V3 ( RV strain pattern)



Left Ventricular Hypertrophy half small square


Left ventricular hypertrophy1
Left Ventricular Hypertrophy half small square


Ecg criteria for rbbb
ECG criteria for RBBB half small square

  • •(1) QRS duration exceeds 0.12 seconds or 2 and half small squares roughly in V1 and may also see it in V2.

  • •(2) RSR complex in V1 may extend to V2.


Ecg criteria for rbbb1
ECG criteria for RBBB half small square

  • •ST/T must be opposite in direction to the terminal QRS(is secondary to the block and does not mean primary ST/T changes).

  • It you meet all above criteria it is then complete right bundle branch block.

  • In incomplete bundle branch block the duration of QRS will be within normal limits.


Rbbb mi
RBBB & MI half small square

  • If abnormal Q waves are present they will not be masked by the RBBB pattern.

  • •This is because there is no alteration of the initial part of the complex RS (in V1) and abnormal Q waves can still be seen.


Significance of rbbb
Significance of RBBB half small square

  • RBBB is seen in :-

  • (1) occasional normal subjects

  • (2) pulmonary embolus

  • (3) coronary artery disease

  • (4) ASD

  • (5) active Carditis

  • (6) RV diastolic overload


Partial incomplete rbbb
Partial / Incomplete RBBB half small square

  • is diagnosed when the pattern of RBBB is present but the duration of the QRS does not exceed 0.12 seconds or roughly 2 and a half small squares.


In next slide you will see
In next slide you will see half small square

  • ECG characteristics of a typical RBBB showing wide QRS complexes with a terminal R wave in lead V1 and slurred S wave in lead V6.

  • Also you see R wave has become upright in V1.QRS duration has also increased making it complete RBBB.


Ecg criteria for lbbb
ECG criteria for LBBB half small square

  • (1)Prolonged QRS complexes, greater than 0.12 seconds or roughly 2 and half small squares in all leads almost.

  • (2)Wide, notched QRS (M shaped) V5, V6

  • (3)Wide, notched QS complexes are seen in V1 (due to spread of activation away from the electrode through septum + LV)

  • (4)In V2, V3 small r wave may be seen due to activation of para septal region


Ecg criteria for lbbb1
ECG criteria for LBBB half small square

  • So look in all leads for QRS duration to make it complete LBBB or incomplete LBBB as u did in RBBB.

  • Look in V5 and V6 for M shaped pattern at summit or apex of R wave.

  • Look for any changes as S-T depression and T wave in inversion if any.


Significance of lbbb
Significance of LBBB half small square

  • LBBB is seen in :-

  • (1) Always indicative of organic heart disease

  • (2) Found in ischemic heart disease

  • (3) Found in hypertension.

  • MI should not be diagnosed in the presence of LBBB →Q waves are masked by LBBB pattern

  • Cannot diagnose the presence of MI with LBBB


Partial incomplete lbbb
Partial / Incomplete LBBB half small square

  • is diagnosed when the pattern of LBBB is present but the duration of the QRS does not exceed 0.12 seconds or roughly 2 and half small squares.


Normal st segment

it's isoelectric. half small square

[i.e. at same level of PR or PQ segment at least in the beginning]

NORMAL ST- SEGMENT


Normal concavity of s t segment
NORMAL CONCAVITY OF S-T SEGMENT half small square

  • It then gradually slopes upwards making concavity upwards and not going more than one small square upwards from isoelectric line or one small square below isoelectric line.

  • In MI this concavity may get lost and become convex upwards called coving of S-T segment.


Abnormalities

ST elevation: half small square

More than one small square

Acute MI.

Prinzmetal angina.

Acute pericarditis.

Early repolarization

ST depression:

More than one small square

Ischemia.

Ventricular strain.

BBB.

Hypokalemia.

Digoxin effect.

Abnormalities





Coving of s t segment
Coving of S-T segment half small square

  • Concavity lost and convexity appear facing upwards.


Diagnostic criteria for ami
Diagnostic criteria for AMI half small square

  • Q wave duration of more than 0.04 seconds

  • Q wave depth of more than 25% of ensuing r wave

  • ST elevation in leads facing infarct (or depression in opposite leads)

  • Deep T wave inversion overlying and adjacent to infarct

  • Cardiac arrhythmias


Abnormalities of st segment
Abnormalities of ST- segment half small square

ischemia

acute MI

early repolariz.

pericarditis



T wave

Normal values. half small square

1.amplitude:

< 10mm in the chest leads.

Abnormalities:

1. Peaked T-wave:

Hyper-acute MI.

Hyperkalemia.

Normal variant

.

2. T- inversion:

Ischemia.

Myocardial infarction.

Myocarditis

Ventricular strain

BBB.

Hypokalemia.

Digoxin effect.

T-wave


Qt interval
QT- interval half small square

Definition: Time interval between beginning of

QRS complex to the end of T wave.

Normally:At normal HR: QT ≤ 11mm (0.44 sec)

Abnormalities:

  • Prolonged QT interval: hypocalcemia and congenital long QT syndrome.

  • Short QT interval: hypercalcemia.


Qt interval should be 1 2 preceding r to r interval
QT Interval half small square- Should be < 1/2 preceding R to R interval -


Qt interval should be 1 2 preceding r to r interval1
QT Interval half small square- Should be < 1/2 preceding R to R interval -

QT interval


Qt interval should be 1 2 preceding r to r interval2
QT Interval half small square- Should be < 1/2 preceding R to R interval -

QT interval


Qt interval should be 1 2 preceding r to r interval3
QT Interval half small square- Should be < 1/2 preceding R to R interval -

R

R

QT interval


Qt interval should be 1 2 preceding r to r interval4
QT Interval half small square- Should be < 1/2 preceding R to R interval -

R

R

QT interval


Qt interval should be 1 2 preceding r to r interval5
QT Interval half small square- Should be < 1/2 preceding R to R interval -

R

R

QT interval


Qt interval should be 1 2 preceding r to r interval6
QT Interval half small square- Should be < 1/2 preceding R to R interval -

R

R

65 - 90 bpm

QT interval


Qt interval should be 1 2 preceding r to r interval7
QT Interval half small square- Should be < 1/2 preceding R to R interval -

R

R

65 - 90 bpm

QT interval

Normal QTc = 0.46 sec




Av blocks
AV Blocks half small square

  • First Degree

    • Prolonged AV conduction time

    • PR interval > 0.20 seconds


1 st degree av block
1 half small squarest Degree AV Block

Prolongation of the PR interval, which is constant

All P waves are conducted


  • 1st degree AV Block half small square:

  • Regular Rhythm

  • PRI > .20 seconds or 5 small squares and is CONSTANT

  • Usually does not require treatment

PRI > .20 seconds


First degree block
First Degree Block half small square

  • prolonged PR interval


Analyze the rhythm
Analyze the Rhythm half small square


Av blocks1
AV Blocks half small square

  • Second Degree

    • Definition

      • More Ps than QRSs

      • Every QRS caused by a P


Second degree av block
Second-Degree AV Block half small square

  • There is intermittent failure of the supraventricular impulse to be conducted to the ventricles

  • Some of the P waves are not followed by a QRS complex.The conduction ratio (P/QRS ratio) may be set at 2:1,3:1,3:2,4:3,and so forth


Second degree
Second Degree half small square

  • Types

    • Type I

      • Wenckebach phenomenon

    • Type II

      • Fixed or Classical


Type i second degree av block wenckebach phenomenon
Type I Second-Degree AV Block: Wenckebach Phenomenon half small square

  • ECG findings

  • 1.Progressive lengthening of the PR interval until a P wave is blocked


2nd degree av block mobitz i also called wenckebach
2nd degree AV Block (“Mobitz I” also called “Wenckebach”):

  • Irregular Rhythm

  • PRI continues to lengthen until a QRS is missing (non-conducted sinus impulse)

    • PRI is NOT CONSTANT

QRS is “dropped”

PRI = .24 sec

PRI = .36 sec

PRI = .40 sec

Pause

Pattern Repeats………….

4:3 Wenckebach (conduction ratio may not be constant)


Type ii second degree av block mobitz type ii
Type II Second-Degree AV “Wenckebach”)Block:Mobitz Type II

  • ECG findings

  • 1.Intermittent or unexpected blocked P waves you don’t know when QRS drops

  • 2.P-R intervals may be normal or prolonged,but they remain constant

  • 4. A long rhythm strip may help


Second degree av block1
Second Degree AV Block “Wenckebach”)

  • Mobitz type I or Winckebach

  • Mobitz type II


Type 1 (Wenckebach) “Wenckebach”)

Progressive prolongation of the PR interval until a P wave is not conducted.

Type 2

Constant PR interval with unexpected intermittent failure to conduct


Mobitz type i
Mobitz Type I “Wenckebach”)


Mobitz type 1
MOBITZ TYPE 1 “Wenckebach”)


  • 2nd degree AV Block (“Mobitz II”) “Wenckebach”):

  • Irregular Rhythm

  • QRS complexes may be somewhat wide (greater than .12 seconds)

  • Non-conducted sinus impulses appear at unexpected irregular intervals

    • PRI may be normal or prolonged but is CONSTANT and fixed

  • Rhythm is somewhat dangerous May cause syncope or may deteriorate into complete heart block (3rd degree block)

  • It’s appearance in the setting of an acute MI identifies a high risk patient

  • Cause: anterioseptal MI,

  • Treatment: may require pacemaker in the case of fibrotic conduction system

PRI is CONSTANT

Non-conducted sinus impulses

“2:1 block”

“3:1 block”


Analyze the rhythm1
Analyze the Rhythm “Wenckebach”)


Second degree mobitz
Second Degree Mobitz “Wenckebach”)

  • Characteristics

    • Atrial rate > Ventricular rate

    • QRS usually longer than 0.12 sec

    • Usually 4:3 or 3:2 conduction ratio (P:QRS ratio)


Analyze the rhythm2
Analyze the Rhythm “Wenckebach”)


Mobitz ii
Mobitz II “Wenckebach”)

  • Definition: Mobitz II is characterized by 2-4 P waves before each QRS. The PR pf the conducted P wave will be constant for each QRS

  • . EKG Characteristics:Atrial and ventricular rate is irregular. P Wave: Present in two, three or four to one conduction with the QRS. PR Interval constant for each P wave prior to the QRS. QRS may or may not be within normal limits.


Mobitz type ii
Mobitz Type II “Wenckebach”)


Mobitz type ii1
Mobitz Type II “Wenckebach”)

  • Sudden appearance of a single, non-conducted sinus P wave...


Advanced second degree av block
Advanced Second-Degree AV Block “Wenckebach”)

Two or more consecutive nonconducted sinus P waves


Complete av block
Complete AV Block “Wenckebach”)

  • Characteristics

    • Atrioventricular dissociation

    • Regular P-P and R-R but without association between the two

    • Atrial rate > Ventricular rate

    • QRS > 0.12 sec


3 rd degree complete av block
3 “Wenckebach”)rd Degree (Complete) AV Block

EKG Characteristics: No relationship between P waves and QRS complexes

Relatively constant PP intervals and RR intervals

Greater number of P waves than QRS complexes


Complete heart block
Complete heart block “Wenckebach”)

  • P waves are not conducted to the ventricles because of block at the AV node. The P waves are indicated below and show no relation to the QRS complexes. They 'probe' every part of the ventricular cycle but are never conducted.


  • 3rd degree AV Block (“Complete Heart Block”) “Wenckebach”):

  • Irregular Rhythm

  • QRS complexes may be narrow or broad depending on the level of the block

  • Atria and ventricles beat independent of one another (AV dissociation)

    • QRS’s have their own rhythm, P-waves have their own rhythm

  • May be caused by inferior MI and it’s presence worsens the prognosis

  • Treatment: usually requires pacemaker

QRS intervals

P-wave intervals – note how the P-waves sometimes distort QRS complexes or T-waves



Third degree complete av block1
Third-Degree (Complete) AV Block “Wenckebach”)

  • The P wave bears no relation to the QRS complexes, and the PR intervals are completely variable


30 av block
30 AV Block “Wenckebach”)

  • AV dissociation

  • atria and ventricles beating on their own

  • no relation between P’s & QRS’s

  • Atrial rate is different from ventricular

  • ventricular rate: 30-60 bpm

  • Rhythm is regular for both

  • QRS can be narrow or wide

  • depends on site of pacemaker!


Key points
Key points “Wenckebach”)

  • Wenckebach

  • look for group beating & changing PR

  • Mobitz II

  • look for reg. atrial rhythm & consistent PR

  • 3o block

  • atrial & ventricular rhythm regular

  • 􀂾 rate is different!!!

  • no consistent PR


Left anterior fascicular block
Left Anterior Fascicular Block “Wenckebach”)

  • Left axis deviation , usually -45 to -90 degrees

  • QRS duration usually <0.12s unless coexisting RBBB

  • Poor R wave progression in leads V1-V3 and deeper S waves in leads V5 and V6

  • There is RS pattern with R wave in lead II > lead III

  • S wave in lead III > lead II

  • QR pattern in lead I and AVL,with small Q wave

  • No other causes of left axis deviation


Lead I “Wenckebach”)

LBB

LPIF

  • Left Anterior Hemiblock (LAHB):

  • Left axis deviation (> -30 degrees) will be noted and there will be a prominent S-wave in Leads II, and III

1.

LASF

2.

Lead III

Lead AVF


Left posterior fascicular block
Left Posterior Fascicular Block “Wenckebach”)

  • Right axis deviation

  • QR pattern in inferior leads (II,III,AVF) small q wave

  • RS patter in lead lead I and AVL(small R with deep S)


Lead I “Wenckebach”)

LBB

LPIF

  • Left Posterior Hemiblock (LPHB):

  • Right axis deviation and there will be a prominent S-wave in Leads I. Q-waves may be noted in III and AVF.

1.

  • Notes on (LPHB):

  • QRS is normal width unless BBB is present

  • If LPHB occurs in the setting of an acute MI, it is almost always accompanied by RBBB and carries a mortality rate of 71%

LASF

2.

Lead III

Lead AVF


Bifascicular bundle branch block
Bifascicular Bundle Branch Block “Wenckebach”)

  • RBBB with either left anterior or left posterior fascicular block

  • Diagnostic criteria

  • 1.Prolongation of the QRS duration to 0.12 second or longer

  • 2.RSR’ pattern in lead V1,with the R’ being broad and slurred

  • 3.Wide,slurred S wave in leads I,V5 and V6

  • 4.Left axis or right axis deviation


Trifascicular block
Trifascicular Block “Wenckebach”)

  • The combination of RBBB, LAFB and long PR interval

  • Implies that conduction is delayed in the third fascicle


Indications for implantation of permanent pacing in acquired av blocks
Indications For Implantation of Permanent Pacing in Acquired AV Blocks

  • 1.Third-degree AV block, Bradycardia with symptoms

  • Asystole

  • e.Neuromuscular diseases with AV block (Myotonic muscular dystrophy)

  • 2.Second-degree AV block with symptomatic bradycardia


Cardiac pacemakers
Cardiac Pacemakers Acquired AV Blocks

  • Definition

    • Delivers artificial stimulus to heart

    • Causes depolarization and contraction

  • Uses

    • Bradyarrhythmias

    • Asystole

    • Tachyarrhythmias (overdrive pacing)


Cardiac pacemakers1
Cardiac Pacemakers Acquired AV Blocks

  • Types

    • Fixed

      • Fires at constant rate

      • Can discharge on T-wave

      • Very rare

    • Demand

      • Senses patient’s rhythm

      • Fires only if no activity sensed after preset interval (escape interval)

    • Transcutaneous vs Transvenous vs Implanted


Cardiac pacemakers2
Cardiac Pacemakers Acquired AV Blocks


Cardiac pacemakers3
Cardiac Pacemakers Acquired AV Blocks

  • Demand Pacemaker Types

    • Ventricular

      • Fires ventricles

    • Atrial

      • Fires atria

      • Atria fire ventricles

      • Requires intact AV conduction


Cardiac pacemakers4
Cardiac Pacemakers Acquired AV Blocks

  • Demand Pacemaker Types

    • Atrial Synchronous

      • Senses atria

      • Fires ventricles

    • AV Sequential

      • Two electrodes

      • Fires atria/ventricles in sequence


Cardiac pacemakers5
Cardiac Pacemakers Acquired AV Blocks

  • Problems

    • Failure to capture

      • No response to pacemaker artifact

      • Bradycardia may result

      • Cause: high “threshold”

      • Management

        • Increase amps on temporary pacemaker

        • Treat as symptomatic bradycardia


Cardiac pacemakers6
Cardiac Pacemakers Acquired AV Blocks

  • Problems

    • Failure to sense

      • Spike follows QRS within escape interval

      • May cause R-on-T phenomenon

      • Management

        • Increase sensitivity

        • Attempt to override permanent pacer with temporary

        • Be prepared to manage VF


Implanted defibrillators
Implanted Defibrillators Acquired AV Blocks

  • AICD

    • Automated Implanted Cardio-Defibrillator

  • Uses

    • Tachyarrhythmias

    • Malignant arrhythmias

      • VT

      • VF


Implanted defibrillators1
Implanted Defibrillators Acquired AV Blocks

  • Programmed at insertion to deliver predetermined therapies with a set order and number of therapies including:

    • pacing

    • overdrive pacing

    • cardioversion with increasing energies

    • defibrillation with increasing energies

    • standby mode

      • Effect of standby mode on Paramedic treatments


Implanted defibrillators2
Implanted Defibrillators Acquired AV Blocks

  • Potential Complications

    • Fails to deliver therapies as intended

      • worst complication

      • requires Paramedic intervention

    • Delivers therapies when NOT appropriate

      • broken or malfunctioning lead

      • parameters for delivery are not specific enough

    • Continues to deliver shocks

      • parameters for delivery are not specific enough and device senses a reset

      • may be shut off (not standby mode) with donut-magnet


Sinus exit block
Sinus Exit Block Acquired AV Blocks

  • Due to abnormal function of SA node

  • MI, drugs, hypoxia, vagal tone

  • Impulse blocked from leaving SA node

  • usually transient

  • Produces 1 missed cycle

  • can confuse with sinus pause or arrest


Sinus block
Sinus block Acquired AV Blocks


Arrthymias and ectopic beats
ARRTHYMIAS AND ECTOPIC BEATS Acquired AV Blocks


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

QRS is slightly different but still narrow,

indicating that conduction through the

ventricle is relatively normal

Atrial Escape Beat

normal ("sinus") beats

sinus node doesn't fire leading to a period of asystole (sick sinus syndrome)

p-wave has different shape indicating it did not originate in the sinus node, but somewhere in the atria. It is therefore called an "atrial" beat


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

Junctional Escape Beat

QRS is slightly different but still narrow,

indicating that conduction through the

ventricle is relatively normal

there is no p wave, indicating that it did not originate anywhere in the atria, but since the QRS complex is still thin and normal looking, we can conclude that the beat originated somewhere near the AV junction. The beat is therefore called a "junctional" or a “nodal” beat


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

QRS is wide and much different ("bizarre") looking than the normal beats. This indicates that the beat originated somewhere in the ventricles and consequently, conduction through the ventricles did not take place through normal pathways. It is therefore called a “ventricular” beat

Ventricular

Escape Beat

there is no p wave, indicating that the beat did not originate anywhere in the atria

actually a "retrograde p-wave may sometimes be seen on the right hand side of beats that originate in the ventricles, indicating that depolarization has spread back up through the atria from the ventricles


The “Re-Entry” Mechanism of Ectopic Beats & Rhythms Acquired AV Blocks

Electrical Impulse

Cardiac Conduction Tissue

Fast Conduction Path

Slow Recovery

Slow Conduction Path

Fast Recovery

  • Tissues with these type of circuits may exist:

    • in microscopic size in the SA node, AV node, or any type of heart tissue

    • in a “macroscopic” structure such as an accessory pathway in WPW


The “Re-Entry” Mechanism of Ectopic Beats & Rhythms Acquired AV Blocks

Premature Beat Impulse

Cardiac Conduction Tissue

Repolarizing Tissue (long refractory period)

Fast Conduction Path

Slow Recovery

Slow Conduction Path

Fast Recovery

  • 1. An arrhythmia is triggered by a premature beat

  • 2. The beat cannot gain entry into the fast conducting pathway because of its long refractory period and therefore travels down the slow conducting pathway only


The “Re-Entry” Mechanism of Ectopic Beats & Rhythms Acquired AV Blocks

Cardiac Conduction Tissue

Fast Conduction Path

Slow Recovery

Slow Conduction Path

Fast Recovery

  • 3. The wave of excitation from the premature beat arrives at the distal end of the fast conducting pathway, which has now recovered and therefore travels retrogradely (backwards) up the fast pathway


The “Re-Entry” Mechanism of Ectopic Beats & Rhythms Acquired AV Blocks

Cardiac Conduction Tissue

Fast Conduction Path

Slow Recovery

Slow Conduction Path

Fast Recovery

  • 4. On arriving at the top of the fast pathway it finds the slow pathway has recovered and therefore the wave of excitation ‘re-enters’ the pathway and continues in a ‘circular’ movement. This creates the re-entry circuit


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Premature Ventricular Contractions (PVC’s, VPB’s, extrasystoles):

  • A ventricular ectopic focus discharges causing an early beat

  • Ectopic beat has no P-wave (maybe retrograde), and QRS complex is "wide and bizarre"

  • QRS is wide because the spread of depolarization through the ventricles is abnormal (aberrant)

  • In most cases, the heart circulates no blood (no pulse because of an irregular squeezing motion

  • PVC’s are sometimes described by lay people as “skipped heart beats”


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Characteristics of PVC's

  • PVC’s don’t have P-waves unless they are retrograde (may be buried in T-Wave)

  • T-waves for PVC’s are usually large and opposite in polarity to terminal QRS

  • Wide (> .16 sec) notched PVC’s may indicate a dilated hypokinetic left ventricle

  • Every other beat being a PVC (bigeminy) may indicate coronary artery disease

  • Some PVC’s come between 2 normal sinus beats and are called “interpolated” PVC’s

The classic PVC – note the compensatory pause

Interpolated PVC – note the sinus rhythm is undisturbed


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • PVC's are Dangerous When:

  • They are frequent (> 30% of complexes) or are increasing in frequency

  • The come close to or on top of a preceding T-wave (R on T)

  • Three or more PVC's in a row (run of V-tach)

  • Any PVC in the setting of an acute MI

  • PVC's come from different foci ("multifocal" or "multiformed")

  • These dangerous phenomenon may preclude the occurrence of deadly arrhythmias:

  • Ventricular Tachycardia

  • Ventricular Fibrillation

The sooner defibrillation takes place, the increased likelihood of survival

“R on T phenomenon”

time

Unconverted V-tach r V-fib

sinus beats

V-tach


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Notes on V-tach:

  • Causes of V-tach

    • Prior MI, CAD, dilated cardiomyopathy, or it may be idiopathic (no known cause)

  • Typical V-tach patient

    • MI with complications & extensive necrosis, EF<40%, d wall motion, v-aneurysm)

  • V-tach complexes are likely to be similar and the rhythm regular

    • Irregular V-Tach rhythms may be due to to:

      • breakthrough of atrial conduction

        • atria may “capture” the entire beat beat

        • an atrial beat may “merge” with an ectopic ventricular beat (fusion beat)

Capture beat - note that the complex is narrow enough to suggest normal ventricular conduction. This indicates that an atrial impulse has made it through and conduction through the ventricles is relatively normal.

Fusion beat - note p-wave in front of PVC and the PVC is narrower than the other PVC’s – this indicates the beat is a product of both the sinus node and an ectopic ventricular focus


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Premature Atrial Contractions (PAC’s):

  • An ectopic focus in the atria discharges causing an early beat

  • The P-wave of the PAC will not look like a normal sinus P-wave (different morphology)

  • QRS is narrow and normal looking because ventricular depolarization is normal

  • PAC’s may not activate the myocardium if it is still refractory (non-conducted PAC’s)

  • PAC’s may be benign: caused by stress, alcohol, caffeine, and tobacco

  • PAC’s may also be caused by ischemia, acute MI’s, d electrolytes, atrial hypertrophy

  • PAC’s may also precede PSVT

Non conducted PAC

Non conducted PAC distorting a T-wave

PAC


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Premature Junctional Contractions (PJC’s):

  • An ectopic focus in or around the AV junction discharges causing an early beat

  • The beat has no P-wave

  • QRS is narrow and normal looking because ventricular depolarization is normal

  • PJC’s are usually benign and require not treatment unless they initiate a more serious rhythm

PJC


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Multifocal Atrial Tachycardia (MAT):

  • Multiple ectopic focuses fire in the atria, all of which are conducted normally to the ventricles

    • QRS complexes are almost identical to the sinus beats

  • Rate is usually between 100 and 200 beats per minute

  • The rhythm is always IRREGULAR

  • P-waves of different morphologies (shapes) may be seen if the rhythm is slow

    • If the rate < 100 bpm, the rhythm may be referred to as “wandering pacemaker”

  • Commonly seen in pulmonary disease, acute cardiorespiratory problems, and CHF

  • Treatments: Ca++ channel blockers, b blockers, potassium, magnesium, supportive therapy for underlying causes mentioned above (antiarrhythmic drugs are often ineffective)

Note different P-wave morphologies when the tachycardia begins

Note IRREGULAR rhythm in the tachycardia


Recognizing and Naming Beats & Rhythms Acquired AV Blocks

  • Paroxysmal (of sudden onset) Supraventricular Tachycardia (PSVT):

  • A single reentrant ectopic focuses fires in and around the AV node, all of which are conducted normally to the ventricles (usually initiated by a PAC)

    • QRS complexes are almost identical to the sinus beats

  • Rate is usually between 150 and 250 beats per minute

  • The rhythm is always REGULAR

  • Possible symptoms: palpitations, angina, anxiety, polyuruia, syncope (d Q)

  • Prolonged runs of PSVT may result in atrial fibrillation or atrial flutter

  • May be terminated by carotid massage

    • u carotid pressure r u baroreceptor firing rate r u vagal tone r d AV conduction

  • Treatment: ablation of focus, Adenosine (d AV conduction), Ca++ Channel blockers

Note REGULAR rhythm in the tachycardia

Rhythm usually begins with PAC


Sinus arrest or exit block
Sinus arrest or exit block Acquired AV Blocks


PAC Acquired AV Blocks


Junctional premature beat
Junctional Premature Beat Acquired AV Blocks

  • single ectopic beat that originates in the AV node or

  • Bundle of His area of the condunction system

  • – Retrograde P waves immediately preceding the QRS

  • – Retrograde P waves immediately following the QRS

  • – Absent P waves (buried in the QRS)


Junctional escape beat
Junctional Escape Beat Acquired AV Blocks


Junctional rhythm1
Junctional Acquired AV BlocksRhythm

  • Rate: 40 to 60 beats/minute (atrial and ventricular)

  • •Rhythm: regular atrial and ventricular rhythm

  • •P wave: usually inverted, may be upright; may precede,

  • follow or be hidden in the QRS complex; may

  • be absent

  • •PR interval: not measurable or less than .20 sec.


Junctional rhythm2
Junctional Acquired AV BlocksRhythm


Maligmalignant pvc patterns
MaligMalignant PVC Acquired AV Blockspatterns

  • Frequent PVCs

    Multiform PVCs

  • Runs of consecutive PVCs

  • R on T phenomenon – PVC that falls on a T

  • wave

  • PVC during acute MI


Types of pvcs
Types of PVCs Acquired AV Blocks

  • Uniform

  • Multiform

  • PVC rhythm patterns

  • – Bigeminy – PVC occurs every other complex

  • – Couplets – 2 PVCs in a row

  • – Trigeminy – Two PVCs for every three complexes


Junctional escape rhythm
Junctional Escape Rhythm Acquired AV Blocks


Ventricular tachycardia vtach
Ventricular tachycardia (VTach) Acquired AV Blocks

  • 3 or more PVCs in a row at a rate of 120 to 200 bts/min-1

    Ventricular fibrillation (VFib)

  • No visible P or QRS complexes. Waves appear as fibrillating waves


Torsades de pointes
Torsades de Pointes Acquired AV Blocks

  • Type of VT known as “twisting of the points.”

  • Usually seen in those with prolonged QT intervals caused by


Why 1500 x
Why “1500 / X”? Acquired AV Blocks

  • Paper Speed: 25 mm/ sec

  • 60 seconds / minute

  • 60 X 25 = 1500 mm / minute

  • Take 6 sec strip (30 large boxes)

  • Count the P/R waves X 10

OR


Atrial Fibrillation Acquired AV Blocks:


Regular irregular
Regular “Irregular” Acquired AV Blocks

  • Premature Beats: PVC

    • Widened QRS, not associated with preceding P wave

    • Usually does not disrupt P-wave regularity

    • T wave is “inverted” after PVC

    • Followed by compensatory ventricular pause



Identifying av blocks
Identifying AV Blocks: Acquired AV Blocks

Name

Conduction

PR-Int

R-R Rhythm


Most important questions of arrhythmias
Most Important Questions of Arrhythmias Acquired AV Blocks

  • What is the mechanism?

    • Problems in impulse formation? (automaticity or ectopic foci)

    • Problems in impulse conductivity? (block or re-entry)

  • Where is the origin?

    • Atria, Junction, Ventricles?


Qrs axis
QRS Axis Acquired AV Blocks

Check Leads:

1 and AVF


Interpreting axis deviation
Interpreting Axis Deviation: Acquired AV Blocks

  • Normal Electrical Axis:

    • (Lead I + / aVF +)

  • Left Axis Deviation:

    • Lead I + / aVF –

    • Pregnancy, LV hypertrophy etc

  • Right Axis Deviation:

    • Lead I - / aVF +

    • Emphysema, RV hypertrophy etc.


Nw axis no man s land
NW Axis (No Man’s Land) Acquired AV Blocks

  • Both I and aVF are –

  • Check to see if leads are transposed (- vs +)

  • Indicates:

    • Emphysema

    • Hyperkalemia

    • VTach


Determining regions of cad st changes in leads
Determining Regions of CAD: ST-changes in leads… Acquired AV Blocks

  • RCA: Inferior myocardium

    • II, III, aVF

  • LCA: Lateral myocardium

    • I, aVL, V5, V6

  • LAD: Anterior/Septal myocardium

    • V1-V4


Regions of the myocardium
Regions of the Myocardium: Acquired AV Blocks

Lateral

I, AVL,

V5-V6

Anterior /

Septal

V1-V4

Inferior

II, III, aVF


Sinus arrhythmia
Sinus Arrhythmia Acquired AV Blocks


Sinus arrest pause
Sinus Arrest/Pause Acquired AV Blocks


Sinoatrial exit block
Sinoatrial Exit Block Acquired AV Blocks






Atrial flutter1
Atrial Flutter Acquired AV Blocks


Atrial fibrillation a fib
Atrial Fibrillation (A-fib) Acquired AV Blocks



Junctional rhythm3
Junctional Rhythm Acquired AV Blocks


Junctional rhythm4
Junctional Rhythm Acquired AV Blocks


Accelerated junctional rhythm
Accelerated Junctional Rhythm Acquired AV Blocks


Junctional tachycardia
Junctional Tachycardia Acquired AV Blocks


Premature ventricular complexes pvc s
Premature Ventricular Complexes (PVC's) Acquired AV Blocks

Note – Complexes not Contractions


Pvc s
PVC’s Acquired AV Blocks

  • Uniformed/Multiformed

  • Couplets/Salvos/Runs

  • Bigeminy/Trigeminy/Quadrageminy


Uniformed pvc s
Uniformed PVC’s Acquired AV Blocks


R on t phenomena
R on T Phenomena Acquired AV Blocks


Multiformed pvc s
Multiformed PVC’s Acquired AV Blocks


Pvc couplets
PVC Couplets Acquired AV Blocks


Pvc salvos and runs
PVC Salvos and Runs Acquired AV Blocks


Bigeminy pvc s
Bigeminy PVC’s Acquired AV Blocks


Trigeminy pvc s
Trigeminy PVC’s Acquired AV Blocks


Quadrageminy pvc s
Quadrageminy PVC’s Acquired AV Blocks


Ventricular escape beats
Ventricular Escape Beats Acquired AV Blocks


Idioventricular rhythm
Idioventricular Rhythm Acquired AV Blocks


Ventricular tachycardia vt
Ventricular Tachycardia (VT) Acquired AV Blocks

  • Rate:101-250 beats/min

  • Rhythm: regular

  • P waves:absent

  • PR interval:none

  • QRS duration:> 0.12 sec. often difficult to differentiate between QRS and T wave

    Note: Monomorphic - same shape

    and amplitude


Ventricular tachycardia vt1
Ventricular Tachycardia (VT) Acquired AV Blocks


V tach
V Tach Acquired AV Blocks


Torsades de pointes tdep
Torsades de Pointes (TdeP) Acquired AV Blocks

  • Rate:150-300 beats/min

  • Rhythm:regular or irregular

  • P waves:none

  • PR interval:none

  • QRS duration:> 0.12 sec. gradual alteration in amplitude and direction of the QRS complexes


Torsades de pointes tdep1
Torsades de Pointes (TdeP) Acquired AV Blocks


Ventricular fibrillation vf
Ventricular Fibrillation (VF) Acquired AV Blocks

  • Rate:CNO as no discernible complexes

  • Rhythm:rapid and chaotic

  • P waves:none

  • PR interval:none

  • QRS duration:none

    Note: Fine vs. coarse?


Ventricular fibrillation vf1
Ventricular Fibrillation (VF) Acquired AV Blocks


Ventricular fibrillation vf2
Ventricular Fibrillation (VF) Acquired AV Blocks


Asystole cardiac standstill
Asystole Acquired AV Blocks (Cardiac Standstill)

  • Rate:none

  • Rhythm:none

  • P waves:none

  • PR interval:not measurable

  • QRS duration:absent


Asystole cardiac standstill1
Asystole Acquired AV Blocks (Cardiac Standstill)


Asystole the mother of all bradycardias
Asystole Acquired AV BlocksThe Mother of all Bradycardias


Atrial pacemaker single chamber
Atrial Pacemaker Acquired AV Blocks(Single Chamber)

pacemaker

  • Capture?


Ventricular pacemaker single chamber
Ventricular Pacemaker Acquired AV Blocks (Single Chamber)

pacemaker


Dual paced rhythm
Dual Paced Rhythm Acquired AV Blocks

pacemaker


Pulseless electrical activity pea
Pulseless Electrical Activity Acquired AV Blocks(PEA)

  • The absence of a detectable pulse and blood pressure

  • Presence of electrical activity of the heart as evidenced by ECG rhythm, but not VF or VT

= 0/0 mmHg

+


Ventricular bigeminy
ventricular bigeminy Acquired AV Blocks

  • The ECG trace below shows ventricular bigeminy, in which every other beat is a ventricular ectopic beat. These beats are premature, wider, and larger than the sinus beats.


Ventricular bigeminy1
ventricular bigeminy Acquired AV Blocks


Ventricular trigeminy
ventricular trigeminy Acquired AV Blocks;

  • The occurrence of more than one type of ventricular ectopic impulse morphology is evidence of multifocal ventricular ectopics. In this example, the ventricular ectopic beats are both wide and premature, but differ considerably in shape


Ventricular trigeminy1
ventricular trigeminy Acquired AV Blocks


Ventricular trigeminy2
ventricular trigeminy Acquired AV Blocks


Myocardial infaraction
MYOCARDIAL INFARACTION Acquired AV Blocks


Diagnosing a mi

12-Lead ECG Acquired AV Blocks

Rhythm Strip

Diagnosing a MI

To diagnose a myocardial infarction you need to go beyond looking at a rhythm strip and obtain a 12-Lead ECG.


St elevation
ST Elevation Acquired AV Blocks

One way to diagnose an acute MI is to look for elevation of the ST segment.


St elevation cont
ST Elevation (cont) Acquired AV Blocks

Elevation of the ST segment (greater than 1 small box) in 2 leads is consistent with a myocardial infarction.


Anterior myocardial infarction
Anterior Myocardial Infarction Acquired AV Blocks

If you see changes in leads V1 - V4 that are consistent with a myocardial infarction, you can conclude that it is an anterior wall myocardial infarction.


Putting it all together
Putting it all Together Acquired AV Blocks

Do you think this person is having a myocardial infarction. If so, where?


Interpretation
Interpretation Acquired AV Blocks

Yes, this person is having an acute anterior wall myocardial infarction.


Putting it all together1
Putting it all Together Acquired AV Blocks

Now, where do you think this person is having a myocardial infarction?


Inferior wall mi
Inferior Wall MI Acquired AV Blocks

This is an inferior MI. Note the ST elevation in leads II, III and aVF.


Putting it all together2
Putting it all Together Acquired AV Blocks

How about now?


Anterolateral mi
Anterolateral MI Acquired AV Blocks

This person’s MI involves both the anterior wall (V2-V4) and the lateral wall (V5-V6, I, and aVL)!


aVR aVL aVF Acquired AV Blocks

V1 V2 V3

V4 V5 V6

I II III

The ST segment should start isoelectric except in V1 and V2 where it may be elevated


Characteristic changes in ami
Characteristic changes in AMI Acquired AV Blocks

  • ST segment elevation over area of damage

  • ST depression in leads opposite infarction

  • Pathological Q waves

  • Reduced R waves

  • Inverted T waves


St elevation hyperacute phase

R Acquired AV Blocks

ST

P

Q

ST elevation hyperacute phase

  • Occurs in the early stages

  • Occurs in the leads facing the infarction

  • Slight ST elevation may be normal in V1 or V2


Deep q wave

R Acquired AV Blocks

ST

P

T

Q

Deep Q wave

  • Only diagnostic change of myocardial infarction

  • At least 0.04 seconds in duration

  • Depth of more than 25% of ensuing R wave


T wave changes

R Acquired AV Blocks

ST

P

T

Q

T wave changes

  • Late change

  • Occurs as ST elevation is returning to normal

  • Apparent in many leads


Bundle branch block
Bundle branch block Acquired AV Blocks

Anterior wall MI

Left bundle branch block

aVR aVL aVF

V1 V2 V3

V4 V5 V6

aVR aVL aVF

V1 V2 V3

V4 V5 V6

I II III

I II III


Sequence of changes in evolving ami
Sequence of changes in evolving AMI Acquired AV Blocks

R

R

R

ST

ST

T

P

P

P

T

Q

Q

S

Q

1 minute after onset

1 hour or so after onset

A few hours after onset

R

ST

T

ST

P

P

P

T

T

Q

Q

Q

A few months after AMI

A day or so after onset

Later changes


Anterior infarction

aVR aVL aVF Acquired AV Blocks

V1 V2 V3

V4 V5 V6

I II III

Anterior infarction

Anterior infarction

Left

coronary

artery


Inferior infarction

aVR aVL aVF Acquired AV Blocks

V1 V2 V3

V4 V5 V6

I II III

Inferior infarction

Inferior infarction

Right

coronary

artery


Lateral infarction

aVR aVL aVF Acquired AV Blocks

V1 V2 V3

V4 V5 V6

I II III

Lateral infarction

Lateral infarction

Left

circumflex

coronary

artery


Diagnostic criteria for ami1
Diagnostic criteria for AMI Acquired AV Blocks

  • Q wave duration of more than 0.04 seconds

  • Q wave depth of more than 25% of ensuing r wave

  • ST elevation in leads facing infarct (or depression in opposite leads)

  • Deep T wave inversion overlying and adjacent to infarct

  • Cardiac arrhythmias


Surfaces of the left ventricle
Surfaces of the Left Ventricle Acquired AV Blocks

  • Inferior - underneath

  • Anterior - front

  • Lateral - left side

  • Posterior - back


Inferior surface
Inferior Surface Acquired AV Blocks

  • Leads II, III and avF look UP from below to the inferior surface of the left ventricle

  • Mostly perfused by the Right Coronary Artery


Inferior leads
Inferior Leads Acquired AV Blocks

  • II

  • III

  • aVF


Anterior surface
Anterior Surface Acquired AV Blocks

  • The front of the heart viewing the left ventricle and the septum

  • Leads V2, V3 and V4 look towards this surface

  • Mostly fed by the Left Anterior Descending branch of the Left artery


Anterior leads
Anterior Leads Acquired AV Blocks

  • V2

  • V3

  • V4


Lateral surface
Lateral Surface Acquired AV Blocks

  • The left sided wall of the left ventricle

  • Leads V5 and V6, I and avL look at this surface

  • Mostly fed by the Circumflexbranch of the left artery


Lateral leads v5 v6 i avl
Lateral Leads Acquired AV BlocksV5, V6, I, aVL


Posterior surface
Posterior Surface Acquired AV Blocks

  • Posterior wall infarcts are rare

  • Posterior diagnoses can be made by looking at the anterior leads as a mirror image. Normally there are inferior ischaemic changes

  • Blood supply predominantly from the Right Coronary Artery


RIGHT Acquired AV Blocks

LEFT

Antero-Septal

V1,V2, V3,V4

Inferior II, III, AVF

Lateral I, AVL, V5, V6

Posterior V1, V2, V3


St segment elevation
ST Segment Elevation Acquired AV Blocks

The ST segment lies above the isoelectric line:

  • Represents myocardial injury

  • It is the hallmark of Myocardial Infarction

  • The injured myocardium is slow to repolarise and remains more positively charged than the surrounding areas

  • Other causes to be ruled out include pericarditis and ventricular aneurysm


St segment elevation1
ST-Segment Elevation Acquired AV Blocks



The ecg in st elevation mi
The ECG in ST Elevation MI Acquired AV Blocks


The hyper acute phase
The Hyper-acute Phase Acquired AV Blocks

Less than 12 hours

  • “ST segment elevation is the hallmark ECG abnormality of acute myocardial infarction” (Quinn, 1996)

  • The ECG changes are evidence that the ischaemic myocardium cannot completely depolarize or repolarize as normal

  • Usually occurs within a few hours of infarction

  • May vary in severity from 1mm to ‘tombstone’ elevation


The fully evolved phase
The Fully Evolved Phase Acquired AV Blocks

24 - 48 hours from the onset of a myocardial infarction

  • ST segment elevation is less (coming back to baseline).

  • T waves are inverting.

  • Pathological Q waves are developing (>2mm)


The chronic stabilised phase
The Chronic Stabilised Phase Acquired AV Blocks

  • Isoelectric ST segments

  • T waves upright.

  • Pathological Q waves.

  • May take months or weeks.


Reciprocal changes
Reciprocal Changes Acquired AV Blocks

  • Changes occurring on the opposite side of the myocardium that is infarcting



Non st elevation mi
Non ST Elevation MI Acquired AV Blocks

  • Commonly ST depression and deep T wave inversion

  • History of chest pain typical of MI

  • Other autonomic nervous symptoms present

  • Biochemistry results required to diagnose MI

  • Q-waves may or may not form on the ECG


Changes in nstemi
Changes in NSTEMI Acquired AV Blocks


Action potentials and electrophysiology

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Repolarised

Action potentials and electrophysiology

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3.2


Lvh and strain pattern
LVH and strain pattern Acquired AV Blocks

Ventricular Strain

Strain is often associated with ventricular hypertrophy

Characterized by moderate depression of the ST segment.


Non-ischaemic ST segment changes: in patient taking digoxin (top) and in patient with left ventricular hypertrophy (bottom)

Channer, K. et al. BMJ 2002;324:1023-1026

Copyright ©2002 BMJ Publishing Group Ltd.


Examples of t wave abnormalities
Examples of T wave abnormalities (top) and in patient with left ventricular hypertrophy (bottom)

Channer, K. et al. BMJ 2002;324:1023-1026

Copyright ©2002 BMJ Publishing Group Ltd.


Sick sinus syndrome
Sick Sinus Syndrome (top) and in patient with left ventricular hypertrophy (bottom)

Sinoatrial block (note the pause

is twice the P-P interval)

Sinus arrest with pause of 4.4 s

before generation and conduction

of a junctional escape beat

Severe sinus bradycardia


Bundle branch block1
Bundle Branch Block (top) and in patient with left ventricular hypertrophy (bottom)


Left bundle branch block
Left Bundle Branch Block (top) and in patient with left ventricular hypertrophy (bottom)

  • Widened QRS (> 0.12 sec, or 3 small squares)

  • Two R waves appear – R and R’ in V5 and V6, and sometimes Lead I, AVL.

  • Have predominately negative QRS in V1, V2, V3 (reciprocal changes).


Right bundle branch block
Right Bundle Branch Block (top) and in patient with left ventricular hypertrophy (bottom)


Where s the mi
Where’s the MI? (top) and in patient with left ventricular hypertrophy (bottom)


Where s the mi1
Where’s the MI? (top) and in patient with left ventricular hypertrophy (bottom)


Where s the mi2
Where’s the MI? (top) and in patient with left ventricular hypertrophy (bottom)


Final one
Final one… (top) and in patient with left ventricular hypertrophy (bottom)


Which one is more tachycardic during this exercise test
Which one is more tachycardic during this exercise test? (top) and in patient with left ventricular hypertrophy (bottom)


Any questions
Any Questions? (top) and in patient with left ventricular hypertrophy (bottom)


Thanks for paying attention i hope you have found this session useful

Thanks for paying attention. (top) and in patient with left ventricular hypertrophy (bottom) I hope you have found this session useful.


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