Ecg basics
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ECG BY DR BASHIR ASSOCIATE PROF MEDICINE SOPORE KASHMIR PowerPoint PPT Presentation

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 BY DR BASHIR ASSOCIATE PROF MEDICINE SOPORE KASHMIR

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Ecg basics

ECG BASICS

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


Ecg by dr bashir associate prof medicine sopore kashmir

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

  • 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


Ecg machine

ECG machine


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


Colour codes given by aha

Colour codes given by AHA


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 by dr bashir associate prof medicine sopore kashmir

  • After applying these leads on different positions then these leads are connected to a connector and then to ECG machine.

  • The speed of machine kept usually 25mm/second.calibration or standardization done while machine is switched on.


Ecg paper

ECG paper

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


Ecg by dr bashir associate prof medicine sopore kashmir

  • The first step while reading ECG is to look for standardization is properly done.

  • Look for this mark and see that this mark exactly covers two big squares on graph.


Standardisation ecg amplitude scale

STANDARDISATION ECG amplitude scale

Normal amplitude

10 mm/mV

Half amplitude

5 mm/mV

Double amplitude

20 mm/mV


Ecg waves

ECG WAVES

  • 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


The normal ecg

The Normal ECG

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

  • 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

  • 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

Slide 13


Ecg by dr bashir associate prof medicine sopore kashmir

NSR


P wave

P-wave

  • 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

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


P wave height 2 and half small squares width also 2 and half small square

P wave height 2 and half small squares ,width also 2 and half small square


Shape of p wave

Shape of P wave

  • 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

  • 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

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 14


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 16


Left atrial enlargement

Left Atrial Enlargement

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 15


Atrial fibrillation

Atrial fibrillation

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 41


Atrial flutter

Atrial flutter

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 40


Junctional rhythm

Junctional rhythm

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


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 43


Paroxysmal atrial tachycardia

Paroxysmal atrial tachycardia

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 39


Normal p r interval

NORMAL P-R INTERVAL

  • PR intervaltime 0.12 seconds to 0.2 seconds.

  • That is three small squares to five small squares.


Pr interval

Definition: 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

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 17


Lengthening of p r interval

Lengthening of P-R interval

  • 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 .


Ecg by dr bashir associate prof medicine sopore kashmir

Slide 44


Q waves

Q WAVES

  • 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


Abnormal q waves

Abnormal Q waves

  • 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


Q wave in septal hypertrophy

Q wave in septal hypertrophy


Qrs complex

QRS COMPLEX

  • 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

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

  • 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

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

ST

Q

S

J point


L v h voltage criteria

L V H-Voltage Criteria

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

  • 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


Right ventricular hypertrophy

Right ventricular hypertrophy

  • 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

  • Causes

  • RBBB

  • Chronic lung disease, PEPosterior MIWPW Type ADextrocardiaDuchenne muscular dystrophy


Right ventricular hypertrophy1

Right Ventricular Hypertrophy

  • 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 hypertrophy2

Right Ventricular Hypertrophy


Right ventricular hypertrophy3

Right ventricular hypertrophy

  • 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

  • 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

  • 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

  • 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

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)


Right ventricular hypertrophy8

Right Ventricular Hypertrophy


Ecg by dr bashir associate prof medicine sopore kashmir

Left Ventricular Hypertrophy


Left ventricular hypertrophy1

Left Ventricular Hypertrophy


Ecg criteria for rbbb

ECG criteria for RBBB

  • •(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

  • •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

  • 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

  • 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

  • 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

  • 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

  • (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

  • 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

  • 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

  • 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.

[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

  • 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:

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


Stress test ecg note the st depression

Stress test ECG – note the ST Depression


Note the arrows pointing st depression

Note the arrows pointing ST depression


St depression troponin t positive is non stemi

ST depression & Troponin T positive is NON STEMI


Coving of s t segment

Coving of S-T segment

  • Concavity lost and convexity appear facing upwards.


Diagnostic criteria for ami

Diagnostic criteria for AMI

  • 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

ischemia

acute MI

early repolariz.

pericarditis


Q waves in myocardial infarction

Q waves in myocardial infarction


T wave

Normal values.

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

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- Should be < 1/2 preceding R to R interval -


Qt interval should be 1 2 preceding r to r interval1

QT Interval- Should be < 1/2 preceding R to R interval -

QT interval


Qt interval should be 1 2 preceding r to r interval2

QT Interval- Should be < 1/2 preceding R to R interval -

QT interval


Qt interval should be 1 2 preceding r to r interval3

QT Interval- 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- 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- 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- 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- Should be < 1/2 preceding R to R interval -

R

R

65 - 90 bpm

QT interval

Normal QTc = 0.46 sec


Atrioventricular av heart block

Atrioventricular (AV) Heart Block


Classification of av heart blocks

Classification of AV Heart Blocks


Av blocks

AV Blocks

  • First Degree

    • Prolonged AV conduction time

    • PR interval > 0.20 seconds


1 st degree av block

1st Degree AV Block

Prolongation of the PR interval, which is constant

All P waves are conducted


Ecg by dr bashir associate prof medicine sopore kashmir

  • 1st degree AV Block:

  • 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

  • prolonged PR interval


Analyze the rhythm

Analyze the Rhythm


Av blocks1

AV Blocks

  • Second Degree

    • Definition

      • More Ps than QRSs

      • Every QRS caused by a P


Second degree av block

Second-Degree AV Block

  • 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

  • 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

  • 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 AVBlock: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

  • Mobitz type I or Winckebach

  • Mobitz type II


Ecg by dr bashir associate prof medicine sopore kashmir

Type 1 (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


Mobitz type 1

MOBITZ TYPE 1


Ecg by dr bashir associate prof medicine sopore kashmir

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

  • 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


Second degree mobitz

Second Degree Mobitz

  • 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


Mobitz ii

Mobitz II

  • 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


Mobitz type ii1

Mobitz Type II

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


Advanced second degree av block

Advanced Second-Degree AV Block

Two or more consecutive nonconducted sinus P waves


Complete av block

Complete AV Block

  • 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

3rd 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

  • 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.


Ecg by dr bashir associate prof medicine sopore kashmir

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

  • 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 block

Third-Degree (Complete) AV Block


Third degree complete av block1

Third-Degree (Complete) AV Block

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


30 av block

30 AV Block

  • 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

  • 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

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Lead I

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

  • 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)


Ecg by dr bashir associate prof medicine sopore kashmir

Lead I

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

  • 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

  • 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

  • Definition

    • Delivers artificial stimulus to heart

    • Causes depolarization and contraction

  • Uses

    • Bradyarrhythmias

    • Asystole

    • Tachyarrhythmias (overdrive pacing)


Cardiac pacemakers1

Cardiac Pacemakers

  • 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


Cardiac pacemakers3

Cardiac Pacemakers

  • Demand Pacemaker Types

    • Ventricular

      • Fires ventricles

    • Atrial

      • Fires atria

      • Atria fire ventricles

      • Requires intact AV conduction


Cardiac pacemakers4

Cardiac Pacemakers

  • Demand Pacemaker Types

    • Atrial Synchronous

      • Senses atria

      • Fires ventricles

    • AV Sequential

      • Two electrodes

      • Fires atria/ventricles in sequence


Cardiac pacemakers5

Cardiac Pacemakers

  • 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

  • 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

  • AICD

    • Automated Implanted Cardio-Defibrillator

  • Uses

    • Tachyarrhythmias

    • Malignant arrhythmias

      • VT

      • VF


Implanted defibrillators1

Implanted Defibrillators

  • 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

  • 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

  • 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


Arrthymias and ectopic beats

ARRTHYMIAS AND ECTOPIC BEATS


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

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


Ecg by dr bashir associate prof medicine sopore kashmir

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

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

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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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”


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Recognizing and Naming Beats & Rhythms

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

PAC


Junctional premature beat

Junctional Premature Beat

  • 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


Junctional rhythm1

Junctional Rhythm

  • 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 Rhythm


Maligmalignant pvc patterns

MaligMalignant PVCpatterns

  • 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

  • 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


Ventricular tachycardia vtach

Ventricular tachycardia (VTach)

  • 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

  • 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”?

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Atrial Fibrillation:


Regular irregular

Regular “Irregular”

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

Notice a Pattern in the PVC’s?


Identifying av blocks

Identifying AV Blocks:

Name

Conduction

PR-Int

R-R Rhythm


Most important questions of arrhythmias

Most Important Questions of Arrhythmias

  • 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

Check Leads:

1 and AVF


Interpreting axis deviation

Interpreting Axis Deviation:

  • 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)

  • 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…

  • 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:

Lateral

I, AVL,

V5-V6

Anterior /

Septal

V1-V4

Inferior

II, III, aVF


Sinus arrhythmia

Sinus Arrhythmia


Sinus arrest pause

Sinus Arrest/Pause


Sinoatrial exit block

Sinoatrial Exit Block


Premature atrial complexes pacs

Premature Atrial Complexes (PACs)


Wandering atrial pacemaker wap

Wandering Atrial Pacemaker (WAP)


Supraventricular tachycardia svt

Supraventricular Tachycardia (SVT)


Wolff parkinson white syndrome wpw

Wolff-Parkinson-White Syndrome (WPW)


Atrial flutter1

Atrial Flutter


Atrial fibrillation a fib

Atrial Fibrillation (A-fib)


Premature junctional complexes pjc

Premature Junctional Complexes (PJC)


Junctional rhythm3

Junctional Rhythm


Junctional rhythm4

Junctional Rhythm


Accelerated junctional rhythm

Accelerated Junctional Rhythm


Junctional tachycardia

Junctional Tachycardia


Premature ventricular complexes pvc s

Premature Ventricular Complexes (PVC's)

Note – Complexes not Contractions


Pvc s

PVC’s

  • Uniformed/Multiformed

  • Couplets/Salvos/Runs

  • Bigeminy/Trigeminy/Quadrageminy


Uniformed pvc s

Uniformed PVC’s


R on t phenomena

R on T Phenomena


Multiformed pvc s

Multiformed PVC’s


Pvc couplets

PVC Couplets


Pvc salvos and runs

PVC Salvos and Runs


Bigeminy pvc s

Bigeminy PVC’s


Trigeminy pvc s

Trigeminy PVC’s


Quadrageminy pvc s

Quadrageminy PVC’s


Ventricular escape beats

Ventricular Escape Beats


Idioventricular rhythm

Idioventricular Rhythm


Ventricular tachycardia vt

Ventricular Tachycardia (VT)

  • 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)


V tach

V Tach


Torsades de pointes tdep

Torsades de Pointes (TdeP)

  • 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)


Ventricular fibrillation vf

Ventricular Fibrillation (VF)

  • 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)


Ventricular fibrillation vf2

Ventricular Fibrillation (VF)


Asystole cardiac standstill

Asystole (Cardiac Standstill)

  • Rate:none

  • Rhythm:none

  • P waves:none

  • PR interval:not measurable

  • QRS duration:absent


Asystole cardiac standstill1

Asystole (Cardiac Standstill)


Asystole the mother of all bradycardias

AsystoleThe Mother of all Bradycardias


Atrial pacemaker single chamber

Atrial Pacemaker (Single Chamber)

pacemaker

  • Capture?


Ventricular pacemaker single chamber

Ventricular Pacemaker (Single Chamber)

pacemaker


Dual paced rhythm

Dual Paced Rhythm

pacemaker


Pulseless electrical activity pea

Pulseless Electrical Activity(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

  • 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


Ventricular trigeminy

ventricular trigeminy;

  • 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


Ventricular trigeminy2

ventricular trigeminy


Myocardial infaraction

MYOCARDIAL INFARACTION


Diagnosing a mi

12-Lead ECG

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

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


St elevation cont

ST Elevation (cont)

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

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

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


Interpretation

Interpretation

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


Putting it all together1

Putting it all Together

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


Inferior wall mi

Inferior Wall MI

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


Putting it all together2

Putting it all Together

How about now?


Anterolateral mi

Anterolateral MI

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


Ecg by dr bashir associate prof medicine sopore kashmir

aVR aVL aVF

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

  • 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

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

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

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

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

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

V1 V2 V3

V4 V5 V6

I II III

Anterior infarction

Anterior infarction

Left

coronary

artery


Inferior infarction

aVR aVL aVF

V1 V2 V3

V4 V5 V6

I II III

Inferior infarction

Inferior infarction

Right

coronary

artery


Lateral infarction

aVR aVL aVF

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

  • 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

  • Inferior - underneath

  • Anterior - front

  • Lateral - left side

  • Posterior - back


Inferior surface

Inferior Surface

  • 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

  • II

  • III

  • aVF


Anterior surface

Anterior Surface

  • 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

  • V2

  • V3

  • V4


Lateral surface

Lateral Surface

  • 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 LeadsV5, V6, I, aVL


Posterior surface

Posterior Surface

  • 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


Ecg by dr bashir associate prof medicine sopore kashmir

RIGHT

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

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


T wave inversion in an evolving mi

T wave inversion in an evolving MI


The ecg in st elevation mi

The ECG in ST Elevation MI


The hyper acute phase

The Hyper-acute Phase

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

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

  • Isoelectric ST segments

  • T waves upright.

  • Pathological Q waves.

  • May take months or weeks.


Reciprocal changes

Reciprocal Changes

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


Reciprocal changes ie s t depression in some leads in mi

Reciprocal Changes ie S-T depression in some leads in MI


Non st elevation mi

Non ST Elevation MI

  • 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


Action potentials and electrophysiology

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Cain(slow)

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Depolarised

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Nain

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Repolarised

Action potentials and electrophysiology

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3.2


Lvh and strain pattern

LVH and strain pattern

Ventricular Strain

Strain is often associated with ventricular hypertrophy

Characterized by moderate depression of the ST segment.


Ecg by dr bashir associate prof medicine sopore kashmir

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

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

Copyright ©2002 BMJ Publishing Group Ltd.


Sick sinus syndrome

Sick Sinus Syndrome

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


Left bundle branch block

Left Bundle Branch Block

  • 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


Where s the mi

Where’s the MI?


Where s the mi1

Where’s the MI?


Where s the mi2

Where’s the MI?


Final one

Final one…


Which one is more tachycardic during this exercise test

Which one is more tachycardic during this exercise test?


Any questions

Any Questions?


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

Thanks for paying attention.I hope you have found this session useful.


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