ECG interpretation & reading

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Saturday, 12 May 2012 1 ECG INTERPRETATION & READING

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Saturday, 12 May 2012 2 1- ANATOMY AND PHYSIOLOGY OF THE HEART 2- ECG 3-SINUS ARRHYTHMIAS 4- JUNCTIONAL ARRHYTHMIA 5- ATRIAL ARRHYTHMIAS 6- VENTRICULAR ARRHYTHMIAS 7- CONDUCTION ARRHYTHMIAS 8- MISCELLANEOUS COURSE OUT LINES

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Saturday, 12 May 2012 3 LOCATION OF THE HEART

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Saturday, 12 May 2012 4 The heart lies in the mediastinum , about two thirds of the mass lies to the left of the body ’ s midline & the pointed end of the heart is the apex , which directed anteriorly & inferiorly & to the right . And the broad portion of the heart opposite to the apex is the base , which is directed superiorly , posteriorly & to the right . LOCATION OF THE HEART

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Saturday, 12 May 2012 5 The heart has two surfaces & two boarders the anterior surface which is deep to the sternum and ribs , the inferior surface , the part between the apex and the right border of the heart and rest on the diaphragm , the right border , faces the right lung & extends from the inferior surface to the base , the left border( pulmonary border ) , faces left lung & extends from the apex to the base . LOCATION OF THE HEART

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Saturday, 12 May 2012 6 1- The heart is a hollow, cone-shaped muscular organ situated in the space between lungs(mediastinum) , its about 12 cm in length & about 9 cm in width . 2- It weighs about 300gms and about the size of owner clenched fist . 3- Its consist of three layers endocardium that lines the interior surface of the heart and valves (endothelial tissue) CARDIAC ANATOMY

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Saturday, 12 May 2012 7 Myocardiu m the middle layer of the heart that consist of striated muscle fibers atrial , ventricular , specialized muscle fibers Epicardium which consist of mesothelial cells it covers the external surface of the heart 4- the heart consist of 4 chambers two atria ,two ventricles . 5- consist of 4 valves 2 atrioventricular valves & 2 semilunar valves CARDIAC ANATOMY

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Saturday, 12 May 2012 8 The electrophysiological characteristics of cardiac muscle that maintain the heart rate and rhythm consist of : 1- EXCITABILITY : the ability of the cardiac muscle to respond to an electrical stimulus . In the resting state the inside – ve & outside +ve CARDIAC PHYSIOLOGY

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Saturday, 12 May 2012 9 2-AUTOMATICITY : the ability of cardiac muscle cells to reach a threshold potential & to be able to generate an action potential without the need for external stimulation 3- CONDUCTIVITY : the ability of cardiac muscle to transmit electrical impulses from SA node through the AV node ,bundle of his, rt & lt bundle branch ,and purkinji fiber CARDIAC PHYSIOLOGY

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Saturday, 12 May 2012 10 4- REFRACTORINESS : the ability of cardiac muscle cell to maintain a steady rhythm by blocking the effect of stronger than normal stimuli which would initiate a further contraction by the heart 5- CONTRACTILITY : the ability of cardiac muscle cells to respond to stimulation by shortening its fibers to produce an efficient pumping action CARDIAC PHYSIOLOGY

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Saturday, 12 May 2012 11 The action potential consist of two phases the depolarization & repolarization . at rest the cell membrane potential equal ( -85 to -95 ) millivolts ,but in stimulation the membrane potential become positive around + 20 millivolts . the cause of the cell ’ s membrane alteration state is due to opening of 2 types of channels . ACTION POTENTIAL

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Saturday, 12 May 2012 12 1- FAST SODIUM CHANNEL : that allow for a large amount of sodium ions to diffuse rapidly across the membrane into the cell causing the cell to become positive or depolarize ( phase 0 ) , phase 1 the spike at the tip of phase 0 , heralds the end of depolarization & the beginning of early repolarization when the sodium channels begin to close . ACTION POTENTIAL

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Saturday, 12 May 2012 13 2- SLOW CALCIUM CHANNEL : they remain open for long period of time , being positively charged , these ions prolong the period of time in which the inside cell remains positive ( phase 2 , plateau ) . (Phase 3) represent the closure of the slow channels resulting in rapid repolarization . calcium , sodium & potassium ions efflux returning the cell to its negative state . ACTION POTENTIAL

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Saturday, 12 May 2012 14 The space between ( phase 2 & 3) represent the S-T segment , phase 3 represent T wave , ( phase 0& 1) represent the QRS complex . In resting period the potassium ion return back into the cell to equilibrium with sodium ion out side the cell represent phase 4 & on ECG the isoelectric line. ACTION POTENTIAL

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Saturday, 12 May 2012 15 It is the means by which the electrical potential generated by the cardiac cells during cardiac cycle can be graphically recorded by using an electrocardiography machine ECG

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Saturday, 12 May 2012 16 Vertically each large square = 0.5 mv , so each small square = 0.1 mv . horizontally each large square = 0.04 second , so each small square = 0.2 second . ECG PAPER

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Saturday, 12 May 2012 17 LEADS AND THEIR POSITIONS

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Saturday, 12 May 2012 18 LEADS AND THEIR POSITIONS

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Saturday, 12 May 2012 19 1- BIPOLAR LEADS L1 : has the +ve electrode attached to Lt arm & -ve to Rt arm L2 :+ve to Lt leg & - ve to Rt arm L3 : +ve to Lt leg & - ve to Lt arm LEADS AND THEIR POSITIONS

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Saturday, 12 May 2012 20 2- UNI POLAR : a - Augmented : AVR : the +ve electrode on the Rt arm AVL : the +ve electrode on the Lt arm AVF : the +ve electrode on the Lt leg b – chest : V1 - rt side of the sternum 4 th intercostal space LEADS AND THEIR POSITIONS

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Saturday, 12 May 2012 21 V2 – Lt side of the sternum on the 4 th intercostals space V3 – mid way between v2 & v4 V4 - mid clavicle line 5 th intercostal space V5 – anterior axillary line , horizontal to v4 V6 – mid axillary line , horizontal to v5 &v6 LEADS AND THEIR POSITIONS

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Saturday, 12 May 2012 22 EXPLAINING P,Q,R,S&T

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Saturday, 12 May 2012 23 P wave : atrial depolarization the 1 st up right wave round in shape the amplitude not more than 2.5mm & up to 0.12 second in duration . Q wave : the 1 st down ward deflection below isoelectric line following the p wave , if present its depth not exceeds one third R wave ( 2mm ) R wave : the 2 nd upward deflection S wave : the 2 nd downward deflection EXPLAINING P,Q,R,S&T

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Saturday, 12 May 2012 24 QRS complex : ventricular depolarization normal measure is 0.08-0.12 second & up to 20mv in amplitude. T wave : ventricular repolarization , rounded upright, not exceeds 0.2 sec of duration & 5mm of amplitude. PR interval : the interval between the beginning of p wave and the beginning of R wave it measures between ( 0.12-0.2) sec EXPLAINING P,Q,R,S&T

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Saturday, 12 May 2012 25 ST segment : the isoelectric line between the end of QRS and the beginning of T wave QT interval : the interval between the beginning of Q wave and the end of T wave , it measures ( 0.32 – 0.40 ) second EXPLAINING P,Q,R,S&T

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Saturday, 12 May 2012 26 We have many ways to measure the heart rate 1- to count number of small boxes between 2 R waves , then to divide 1500 by number of small boxes . 2- to count number of large boxes between 2 R waves , then divide 300 by number of large boxes . MEASUREMENT OF HEART RATE

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Saturday, 12 May 2012 27 Number of small boxes = 33 , and the number of large boxes = 6.5 if you divide 1500 /33 or 300 /6.5 you will the same result 46 bpm MEASUREMENT OF HEART RATE

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Saturday, 12 May 2012 28 MEASUREMENT OF HEART RATE

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Saturday, 12 May 2012 29 Occurs when the SA node discharge an impulses regularly at a rate less than 60 bpm , the complexes and intervals remain within normal time duration SINUS BRADY CARDIA

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Saturday, 12 May 2012 30 SINUS BRADY CARDIA

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Saturday, 12 May 2012 31 1- RHYTHM : regular 2-RATE : less than 55 bpm . 3- P WAVE : normal (up right ,rounded ) 4-PR INTERVAL : normal 5- QRS COMPLEX : normal 6-ST SEGMENT : isoelectric 7- T WAVE : normal ( symmetric , rounded ) 8-CONDUCTION : normal electrical path way SINUS BRADY CARDIA

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Saturday, 12 May 2012 32 CAUSES : 1- vagal stimulation 2- increased intra cranial pressure 3- myocardial infarction 4- use of beta blockers SINUS BRADY CARDIA

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Saturday, 12 May 2012 33 Occurs when the SA node discharges an impulses in a rate of more than 100 bpm , some times the rate can be as high as 180 bpm SINUS TACHY CARDIA

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Saturday, 12 May 2012 34 SINUS TACHY CARDIA

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Saturday, 12 May 2012 35 1- RHYTHM : regular 2-RATE : more than 100bpm . 3- P WAVE : normal (up right ,rounded ) 4-PR INTERVAL : normal 5- QRS COMPLEX : normal duration 6-ST SEGMENT : isoelectric 7- T WAVE : normal ( symmetric , rounded ) 8-CONDUCTION : normal electrical path way SINUS TACHYCARDIA

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Saturday, 12 May 2012 36 CAUSES : 1-fever 2- anxiety 3-hypo volemia 4- congestive heart failure SINUS TACHY CARDIA

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Saturday, 12 May 2012 37 The rate usually increase with inspiration & decrease with expiration . During expiration the parasympathetic vagal tone activated , so the heart rate decreased . During inspiration the stretch receptors in the lung stimulate the cardioinhibitary centers in the medulla via fibers in the vagus nerve , so the heart rate increased . SINUS ARRHYTHMIA

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Saturday, 12 May 2012 38 SINUS ARRHYTHMIA

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Saturday, 12 May 2012 39 1- RHYTHM : rate increased with inspiration ,decreased with expiration 2-RATE : varies between 50 -100 bpm . 3- P WAVE : normal (up right ,rounded ) 4-PR INTERVAL : normal 5- QRS COMPLEX : normal duration 6-ST SEGMENT : isoelectric 7- T WAVE : normal ( symmetric , rounded ) 8-CONDUCTION : normal electrical path way SINUS ARRHYTHMIA

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Saturday, 12 May 2012 40 CAUSES : During inspiration venous blood returning to the heart increases and vagal tone decreases resulting on tachy cardia & vice versa SINUS ARRHYTHMIA

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Saturday, 12 May 2012 41 When the SA node fails to initiate an impulse at a specific time resulting in an absence of a PQRST complexes for at least one complete cardiac cycle some times up to three consecutive cycles , all complexes and intervals within normal limits SINUS ARREST

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Saturday, 12 May 2012 42 CAUSES : 1- inferior MI 2- increased vagal tone 3- digoxin toxicity SINUS ARREST

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Saturday, 12 May 2012 43 The site of the wandering pacemaker originates from at least three different sites in the cardiac muscles , its position may shift to another irritable foci in the atria and the AV junction , the size and the shape of the P wave vary depending on the site of origin for that particular cycle WANDERING PACEMAKER

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Saturday, 12 May 2012 44 1- RHYTHM : vary according to the site of initial impulse 2-RATE : varies from normal to low upon the site 3- P WAVE : varies in shape and direction 4-PR INTERVAL : vary depending on atrial origin WANDERING PACEMAKER

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Saturday, 12 May 2012 45 5- QRS COMPLEX : normal duration 6-ST SEGMENT : isoelectric 7- T WAVE : normal ( symmetric , rounded ) 8-CONDUCTION : normal electrical path way after passing the AV junction WANDERING PACEMAKER

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Saturday, 12 May 2012 46 CAUSES : 1- digitalis toxicity 2- MI WANDERING PACEMAKER

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Saturday, 12 May 2012 47 ARRHYTHMIAS OF ATRIA

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Saturday, 12 May 2012 48 Occur when an ectopic atrial focus discharge an impulse before the next anticipated sinus node activation , these ectopic Ps have a bizarre appearance and can be pointed , inverted or notched ATRIAL ECTOPIC BEAT

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Saturday, 12 May 2012 49 ATRIAL ECTOPIC BEAT

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Saturday, 12 May 2012 50 1- RHYTHM : regular except for ectopic beat 2-RATE : normal except for ectopic beat 3- P WAVE :normal ,pointed in atrial ectopic beat 4-PR INTERVAL : normal except for ectopic beat 5- QRS COMPLEX : normal duration ATRIAL ECTOPIC BEAT

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Saturday, 12 May 2012 51 6-ST SEGMENT : isoelectric 7- T WAVE : normal ( symmetric , rounded ) 8-CONDUCTION : normal electrical path way after passing the AV junction ATRIAL ECTOPIC BEAT

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Saturday, 12 May 2012 52 CAUSES : 1- IHD 2-electrolytes imbalance 3-CHF ATRIAL ECTOPIC BEAT

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Saturday, 12 May 2012 53 Occurs when multiple irritable focuses in both atria started to initiate impulses that resulting in chaotic , irregular excitation of the atrium . Its characterized by the appearance of numerous irregular fibrillatory waves on the rhythm strip , the ventricular wave also irregular depending on the conduction of the atrial impulses conduction through the AV junction . ATRIAL FIBRILLATION

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Saturday, 12 May 2012 54 ATRIAL FIBRILLATION

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Saturday, 12 May 2012 55 1- RHYTHM : irregular for both atrium & ventricles . 2- RATE : atrial ( 400-500 )bpm , ventricular ( 80 -180 ) bpm ( varies upon conduction . 3- PR INTERVAL : absent . 4- QRS COMPLEX : normal shape & duration 5-CONDUCTION : bizarre atrial conduction , normal conduction after AV junction . ATRIAL FIBRILLATION

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Saturday, 12 May 2012 56 CAUSES : 1- anterior myocardial infarction . 2- inferior myocardial infarction . 3- valvular heart disease . ATRIAL FIBRILLATION

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Saturday, 12 May 2012 57 occurs when there is a rapid but regular excitation from an ectopic focus in the atrium at rate of 300 bpm . The ventricular waves are regular , the ratio between atrial and ventricular rate varies between ( 2:1 & 3:1& 4:1 ) . ATRIAL FLUTTER

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Saturday, 12 May 2012 58 ATRIAL FLUTTER

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Saturday, 12 May 2012 59 1- RHYTHM : atrial rhythm is regular ,ventricular rhythm regular & depend on the conduction . 2-RATE : atrial 288 bpm , ventricular 96 bpm . Ratio 3: 1 . 3- P WAVE : saw-tooth ; no true p waves , only flutter or F waves . 4- PR INTERVAL : absent . ATRIAL FLUTTER

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Saturday, 12 May 2012 60 5- QRS COMPLEX : normal shape & duration . 6- T WAVE : difficult to define . 7- CONDUCTION : ectopic atrial foci , impulses follow normal path way after AV junction . ATRIAL FLUTTER

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Saturday, 12 May 2012 61 CAUSES : 1- atrial enlargement . 2- hyper thyroidism . 3- inferior myocardial infarction . 4- anterior myocardial infarction . ATRIAL FLUTTER

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Saturday, 12 May 2012 62 During an episode of SVT the heart beat is not controlled by SA node , another part of the heart overrides this role with faster impulses . The source of the impulse is some where above ventricles , but the impulse then spread to the ventricles so the heart beats faster than normal . SUPRAVENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 63 SUPRAVENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 64 1- RATE : between (140 – 200) bpm . 2- RHYTHM : R-R interval regular . 3- P WAVE : absent . 4- P-R INTERVAL : absent . SUPRAVENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 65 5- QRS COMPLEX : narrow < 0.06 second . 6- T WAVE : peaked T wave . 7- CONDUCTION : the ventricles is stimulated from some where in the atria . SUPRAVENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 66 CAUSES : 1- hypothyroidism . 2- anxiety . 3- pericarditis . 4- heart failure . 5- structural abnormality . SUPRAVENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 67 This type occurs when SA node & the atria are unable to discharge an impulse to depolarize both atria & ventricles , therefore an ectopic focus in the surrounding junctional tissue take the responsibility as apace maker at a rate of ( 40-60 ) bpm . The P wave may be absent, inverted & next QRS complex ; depends upon its origin . JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 68 JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 69 JUNCTIONAL RHYTHM

JUNCTIONAL RHYTHM :

Saturday, 12 May 2012 70 JUNCTIONAL RHYTHM 1-RHYTHM : regular . 2- RATE : 50 bpm , ( 40 – 60 ) bpm . 3-P WAVE : Absent . 4- QRS COMPLEX : normal configuration & duration . 5- T WAVE : normal . 6- CONUCTION : the atria is stimulated by the junctional tissue after activation after or with the activation of the ventricles .

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Saturday, 12 May 2012 71 CAUSES : 1- acute myocardial infarction . 2- digoxin toxicity . JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 72 This occur when the junctioal tissue discharges impulses at a rate of ( 60 – 100 ) bpm . the P wave may be absent , inverted or after QRS complex. ACCELARATED JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 73 ACCELARATED JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 74 1- RHYTHM : regular . 2- RATE : 83 bpm . 3- P WAVE : after QRS complex . 4- QRS COMPLEX : normal configuration & duration . 5-T WAVE : Normal . 6- CONDUCTION : atria activated after the ventricles so P wave comes after QRS complex . ACCELARATED JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 75 CAUSES : 1- congestive heart failure . 2- cardiogenic shock . NOTE : this type of arrhythmia start & end gradually . ACCELARATED JUNCTIONAL RHYTHM

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Saturday, 12 May 2012 76 VENTRICULAR ARRHYTHMIAS

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Saturday, 12 May 2012 77 Occurs when an ectopic focus discharging an impulse ahead of the next anticipated sinus node beat . the ectopic beat consist of QRS & T waves that are opposite together in their directions , if QRS positive direction the P in negative direction . The ectopic beat may occur after T wave or on the top of T wave . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 78 VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 79 Multi focal means that the ectopic beat has more than one foci , that discharge many shapes of QRS & T . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 80 That means that 2 consequences impulses discharged prior to the next anticipated sinus rhythm impulse . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 81 VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 82 Bigemini : the ectopic beat occurs every other one beat . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 83 Trigemini : the ectopic beat occurs every other 2 sinus beats . Sequential : when more than 3 consequences ectopic beats occur . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 84 Occurs when the VEB occurs on the top of previous sinus rhythm T wave which dangerous because may lead to torsades de pointes . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 85 occurs when there is no time for compensatory pause for the SA node after the occurrence of VEB . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 86 1-RHYTHM : depends on the underlying rhythm, in regular rhythm the ectopic beat causes irregularity . 2- RATE : depends on underlying rhythm , but VEB can occur any time . 3- P WAVE : in ectopic beat its not identifiable or hidden in QRS because of force of ventricular depolarization . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 87 4- P-R INTERVAL : normal ( 0.12-0.2 ) if underlying rhythm is sinus . 5- QRS COMPLEX :always widened & distorted with no preceding P wave , the duration is greater than 0.12 second , and some times pointed in the opposite direction in comparing with the sinus complexes . If the QRS in normal appearance & duration the origin is situated near the bundle of his but if wide & bizarre the focus is situated in the purkinji fiber . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 88 6- T WAVE : usually deflected in the opposite direction of the QRS complex of the VEB . 7- CONDUCTION : the atria may not be depolarized , the ventricles are stimulated by their own pace maker . HINT : following the VEB there is a complete compensatory pause allowing the SA node to regain control as a pace maker . VENTRICULAR ECTOPIC BEAT

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Saturday, 12 May 2012 89 CAUSES : 1- acute myocardial infarction . 2- electrolytes imbalance . 3- ingestion of stimulants ( tea , coffee ) . VENTRICULAR ECTOPIC BEAT

VENTRICULAR TACHYCARDIA :

Saturday, 12 May 2012 90 VENTRICULAR TACHYCARDIA Develops when there is more than 3 consequences VEBs and the heart rate exceeds 100 bpm , such activity is due to enhanced automaticity and re-entry within the purkinji fibers . P wave not visible because its hidden in the QRS complex .

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Saturday, 12 May 2012 91 VENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 92 A- start of spindle increase QRS amplitude B-end of spindle & start of node . C- end of node & start of next spindle . Note the positive initial deflection . TORSADES DE POINTES

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Saturday, 12 May 2012 93 1- RHYTHM :regular . 2-RATE : ventricular 180 bpm , it range is ( 100-200) bpm . 3-P WAVE : not present , or hidden in the QRS complex . 4-P-R INTERVAL : not present . 5- QRS COMPLEX : uniform configuration . 6- CONDUCTION : the ventricles are directly stimulated by an ectopic focus within the purkinji fibers network . VENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 94 CAUSES : 1-hypokalemia . 2-cardiomyopathy . 3-acute myocardial infarctions . VENTRICULAR TACHYCARDIA

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Saturday, 12 May 2012 95 chaotic un coordinated ventricular depolarization , usually initiated by the R wave of a VEB striking the peak of the T wave of preceding beat . Because of chaotic activity the muscle mass on quivers & cardiac out put falls rapidly . VENTRICULAR FIBRILLATION

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Saturday, 12 May 2012 96 VENTRICULAR FIBRILLATION

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Saturday, 12 May 2012 97 1- RHYTHM : irregular , chaotic . 2-RATE : cannot be determined . 3- P WAVE : absent . 4- P-R INTERVAL : absent . 5- QRS COMPLEX : replaced by f wave . 6- CONDUCTION : un coordinated ventricular depolarization . VENTRICULAR FIBRILLATION

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Saturday, 12 May 2012 98 CAUSES : 1- R on T phenomenon . 2- acute myocardial infarction . 3- hypokalemia . 4- hypothermia . 5- sever acidosis or alkalosis . VENTRICULAR FIBRILLATION

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Saturday, 12 May 2012 99 Occurs when the electrical impulses from the SA node doesn ’ t reach the ventricles , in this situation the ventricles muscles take the role as apace maker and widened QRS may appear . VENTRICULAR STANDSTILL

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Saturday, 12 May 2012 100 VENTRICULAR STANDSTILL

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Saturday, 12 May 2012 101 1- RHYTHM : no ventricular activity , the atrial activity appear . 2- RATE : atrial regular . 3- P WAVE : present . 4- P-R INTERVAL : absent . 5- QRS COMPLEX : absent . 6- CONDUCTION : no conduction through the ventricles . VENTRICULAR STANDSTILL

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Saturday, 12 May 2012 102 CAUSES : 1- complete heart block . 2- respiratory failure . 3- cardiogenic shock . 4- acute myocardial infarction . VENTRICULAR STANDSTILL

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Saturday, 12 May 2012 103 This arrhythmia occurs when all supra ventricular pace makers ( SA node , AV junction , bundle of his , bundle branch ) fail to elicit an electrical impulse ; the ventricles take over as a pace maker , firing at their own inherent rate of ( 30 – 40 ) bpm . IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 104 IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 105 1- RHYTHM : regular R-R interval . 2- RATE :(30-40) bpm . 3- P WAVE : absent . 4-QRS COMPLEX : wide & bizarre . 5- CONDUCTION : electrical impulses arises from the purkinji fibers or ventricular myocardium . IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 106 CAUSES : 1- cardiogenic shock . 2- medication effects like adrenaline . IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 107 This arrhythmia occurs when the SA node & AV junction fail to initiate impulse the ventricles take over the role as a pace maker at a rate about ( 50-100) bpm . ACCELERATED IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 108 ACCELERATED IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 109 1-RATE : 60 bpm . 2- RHYTHM : regular R-R interval . 3- P WAVE : absent . 4- QRS COMPLEX : wide & bizarre . 5- T WAVE : caught up in ST segment . 6- CONDUCTION : pace maker site is in bundle branch , purkinji fibers or myocardium ACCELERATED IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 110 CAUSES : 1- Acute myocardial infarctions . 2- digoxin toxicity . ACCELERATED IDIOVENTRICULAR RHYTHM

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Saturday, 12 May 2012 111 ATRIOVENTRICULAR BLOCKS

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Saturday, 12 May 2012 112 Occurs when there is a delay in the transmission of electrical impulse through the AV node to the ventricles . FIRST DEGREE AV BLOCK

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Saturday, 12 May 2012 113 FIRST DEGREE AV BLOCK

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Saturday, 12 May 2012 114 1- RHYTHM : regular . 2- RATE : 45 bpm < 50bpm 3- P WAVE : normal . 4- P-R INTERVAL : 0.28 seconds 5- QRS COMPLEX : normal . 6- CONDUCTION : follow normal conduction pathway but there is a delay in the process . FIRST DEGREE AV BLOCK

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Saturday, 12 May 2012 115 CAUSES : 1- acute myocardial infarction . 2- digoxin toxicity . FIRST DEGREE AV BLOCK

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Saturday, 12 May 2012 116 Occurs when conduction through the AV junction become progressively difficult with each successive impulse until finally a ventricular depolarization doesn ’ t occur . SECOND DEGREE AV BLOCK MOBITZ-1

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Saturday, 12 May 2012 117 SECOND DEGREE AV BLOCK MOBITZ-1

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Saturday, 12 May 2012 118 1-RATE :ventricular = 68 bpm , atrial = 75 bpm . 2- RHYTHM : atrial regular , but ventricular irregular . 3- P WAVE : normal . 4-P-R INTERVAL : lengthening with each successive beat . 5-QRS COMPLEX :normal . SECOND DEGREE AV BLOCK MOBITZ-1

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Saturday, 12 May 2012 119 6- CONDUCTION : some of the impulses from the atria are blocked . P-R interval gets progressively longer until one P wave is not followed by QRST . SECOND DEGREE AV BLOCK MOBITZ-1

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Saturday, 12 May 2012 120 CAUSES : 1-rehumatic fever . 2- inferior myocardial infarction . 3- digoxin toxicity . SECOND DEGREE AV BLOCK MOBITZ-1

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Saturday, 12 May 2012 121 In this arrhythmia 2 or more atrial impulses conducted normally , then the next impulse blocked without warning . Block may occur occasionally or at regular intervals . ( for every third beat ) ( 3:1) . SECOND DEGREE AV BLOCK MOBITZ-2

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Saturday, 12 May 2012 122 SECOND DEGREE AV BLOCK MOBITZ-2

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Saturday, 12 May 2012 123 1- RATE : atrial 64 bpm , but ventricular depend on conduction . 2- RHYTHM : P-P interval regular , R-R interval irregular . 3- P WAVE : normal . 4- P-R INTERVAL : 0.16 sec , absent in missed beats . SECOND DEGREE AV BLOCK MOBITZ-2

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Saturday, 12 May 2012 124 5- QRS COMPLEX : normal, some dropped beats . 6- T WAVE : normal , some dropped as QRS 7- CONDUCTION : Third atrial impulse is blocked . SECOND DEGREE AV BLOCK MOBITZ-2

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Saturday, 12 May 2012 125 CAUSES : 1- degenerative changes in conduction system 2- anterior myocardial infarction . 3- coronary artery disease . SECOND DEGREE AV BLOCK MOBITZ-2

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Saturday, 12 May 2012 126 Occurs when the electrical impulses above the AV node are blocked , therefore no impulses conducted to the ventricles , if SA node blocked the junctional arises , if the block involve the junctional tissue , the idiodventricular rhythm arises . COMPLETE HEART BLOCK

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Saturday, 12 May 2012 127 COMPLETE HEART BLOCK

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Saturday, 12 May 2012 128 1-RATE : atrial rate ( 60-100) bpm, ventricular rate (30-40) bpm . 2- RHYTHM : P-P interval regular , R-R interval regular . 3-P WAVE : normal . 4-P-R INTERVAL : absent ( no relation between atria& ventricles ) COMPLETE HEART BLOCK

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Saturday, 12 May 2012 129 5- QRS COMPLEX : depend on the site of pace maker , ( wide = purkinji fibers ) ( normal =junctional tissue ) 6- T WAVE : absent . 7- CONDUCTION : the atria & ventricles have independent pacemaker ,so there is no relationship between both . COMPLETE HEART BLOCK

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Saturday, 12 May 2012 130 CAUSES : 1-inferior myocardial infarction . 2- digoxin toxicity . 3- degeneration of conduction system . COMPLETE HEART BLOCK

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Saturday, 12 May 2012 131 BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 132 Occurs when the right ventricle is activated abnormally by the interventricular septum . In RBBB the following take place 1- initial impulse activate interventricular septum . 2- the left bundle branch stimulates the left ventricle to depolarize , 3- the impulse is transmitted across the septum below the level of block . RIGHT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 133 RIGHT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 134 By using chest leads V1 & V6 you see : 1- rSR shape in V1 : a- small R wave in V1 b- large S wave in V1 c- second large R wave in V1 2- Q wave in V6 3- prominent ( deep & wide ) S wave in V6 . RIGHT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 135

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Saturday, 12 May 2012 136 CAUSES : 1- right ventricular hypertrophy 2- anterior myocardial infarction . 3-pulmonary embolism . 4- cardiomyopathy . RIGHT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 137 Occurs when left ventricle is abnormally activated by impulses spreading through the interventricular septum by the right ventricle LEFT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 138 LEFT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 139 By using the chest leads V1 & V6 you will find the following : 1- inverted T wave . 2- RSR ” in V6 . 3- no Q wave . 4- wide QRS > 0.12 second . LEFT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 140

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Saturday, 12 May 2012 141 CAUSES : 1- valvular heart disease . 2- acute myocardial infarctions . 3- hypertension . LEFT BUNDLE BRANCH BLOCK

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Saturday, 12 May 2012 142 This abnormality occurs when the right atria become enlarged due to the following : 1- tricuspid valve stenosis . 2- pulmonary hypertention . RIGHR ATRIAL HYPERTROPHY

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Saturday, 12 May 2012 143 RIGHT ATRIAL HYPERTROPHY

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Saturday, 12 May 2012 144 CRITERIA : differentiated by looking on P wave if amplitude > 2.5 mm in L2 . RIGHT ATRIAL HYPERTROPHY

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Saturday, 12 May 2012 145 Left atrial hypertrophy caused by mitral valve stenosis ( the valve between left atrium & left ventricle ) . The criteria of left atrial hypertrophy is P wave duration > 0.12 second . LEFT ATRIAL HYPERTROPHY

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Saturday, 12 May 2012 146 LEFT ATRIAL HYPERTROPHY

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Saturday, 12 May 2012 147 Right ventricular hypertrophy caused by pulmonary valve stenosis . The criteria of ECG changes is skolo law that says : if R wave in V1 + S wave in V6 > 35 mv that means the patient has right ventricular hypertrophy . RIGHT VENTRICULAR HYPERTROPHY

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Saturday, 12 May 2012 148 RIGHT VENTRICULAR HYPERTROPHY

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Saturday, 12 May 2012 149 Left ventricular hypertrophy caused by aortic valve stenosis . The criteria of determination of left ventricular hypertrophy is skolo law that says : if S wave in V1 + R wave in V6 > 35 mv means that the patient has left ventricular hypertrophy . LEFT VENTRICULAR HYPERTROPHY

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Saturday, 12 May 2012 150 That means the heart lies in the right area , this abnormality is only congenital. The criteria of interpretation is L1 & AVR : when L1 is in negative deflection & AVR in positive deflection . DEXTROCARDIA

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Saturday, 12 May 2012 151 DEXTROCARDIA

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Saturday, 12 May 2012 152 THANK YOU

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