Understanding ECG

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Cardiology

- Function of the heart is mainly pumping the blood, Regulate the circulation.- Valves of the heart:

A- Semi Lunar: 1- Aortic between Left Ventricle and Aortic Arch.2- Pulmonary between Right Ventricle and Pulmonary artery.

B- A-V (Atrio-Ventricular):1- Mitral between left Atrium and left Ventricle.2- Tricuspid between right Atrium and right Ventricle.

- Heart position is in the Mediastenum .- Heart size is Closed Fist, when opening the chest first part you see is Right Ventricle, Most

Anterior.

Gathered by: Abdulmalik Al-Ghamdi, Nassir Al-Saeed, Abdulrahman Abu-Khashba, , Saud Khan Salih Ashgar, Mustafa Al-Zaytooni, Raghad Shawoosh. Written by: Hawra Al-Eirani _ Special Thanks Goes to: Khalid AlShabrawy

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- Heart Layers: (outer to inner)1- Pericardium.2- Myocardium.3- Endocardium.

- Collection of Fluid in the Pericardium called Cardiac Temponae ( Doesn’t Pump Well).- Circulation of the Blood:

Superior & Inferior VenaCava Right Atrium Right Ventricle Pulmonary artery Lung Pulmonary vein Left Atrium Left Ventricle Aorta The Whole Body.

- Borders of the Heart: 1- Right Border:

a- Superior & Inferior VenaCava.b- Right Atrium.

2- Left Border:a- Left Atrium & Ventricle.b- Pulmonary Artery.c- Aortic Artery.

3- Inferior Surface:a- Right Ventricle.b- Apex Left Ventricle.

- Blood Supply to the heart is the Coronary Arteries.- Any Vein drains in the Right Atrium.- Bundle Branch Block: means some of the Myocardiaum will get the Impulses and the rest will

not, still be relaxed.- Controlling of Blood Flow: Valves:

1- During Systole:a- A-V Closed.b- Semi Lunar Opened.

2- During Diastole:a- A-V Opened.b- Semi Lunar Closed.

- Sound heard of the heart is Due to Closure of the Valves.- S1 Sound [Closure of A-V] Systole Occurs S2 Sound [ Closure of Semi Lunar] Diastole Occurs - All Myocardium cells work as one cell Sensetium, in case of Cardiac Damage, the damage

cell will release Troponin and Myocin into the blood Known as: Cardiac Markers.


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- Conduction System: [ SA AV Bundle Branch / Purkinje fibers.] - SA node is the base maker sends impulses to the A-V, The A_V node waits a while before

sending so the Ventricles relax and get fille with blood to contract. Then, the A-V node sends the Impulses Throught the Bundle Branchs then, to Purkinje fibers.

- Cardiac Cycle :

- Stroke Volume = 70-80 ml ejected with every beat.- Abnormal Sounds ( MURMURS):

In Murmur: Gathered by: Abdulmalik Al-Ghamdi, Nassir Al-Saeed, Abdulrahman Abu-Khashba, , Saud Khan Salih Ashgar, Mustafa Al-Zaytooni, Raghad Shawoosh. Written by: Hawra Al-Eirani _ Special Thanks Goes to: Khalid AlShabrawy

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a- Stenosis Sound heard when the Valve is OPEN.b- Regarge Sound heard when the Valve is CLOSED.

In A-V Valves Diastole Open Stenosis. Systole Closed Regergitation.

In Semi Lunar Valves Diastole Closed Regergitation. Systole Open Stenosis

- ElectroCardioGram (ECG):

- Waves:1- P Wave Atrium Depolarization (Any problem with right or left atrium will show in

this wave in the ECG).2- QRS Complex Ventricle Depolarization, Atrium repolarization ( The wave will show

the Impulses going through Septal, Base, Apex of the heart. Ventricular Depolarization is stronger than Atrial Re-Polarization.

3- T Wave Ventricular Re-Polarization .- Segments: ( Iso-Electric Line)

1- ST Segment To Identify Ischemia.2- PR Segment For A-V Activity.3- TP Segment For the Base Line.

- Interval: (Wave + Segment)1- PR interval P wave + PR Segment.2- QT interval QRS Complex + ST segment.

- In the ECG paper: 1 Big Square = 5 Small Square of 1 line. Therefore, 1 Big Square = 0,2sec and 1 Small Square = 0,04sec.

- In 1 min 300 Big Square.- Heart Rate = 60-100 Counted from R-R only 1 Cycle (big squares).- HR= 300/no. of squares.


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- Rhythem between R-R ( must compare between 3-4 cycles) (big square)- Accessory Pathway Abnormalities:

1- P-R Interval: Normally takes 3-5 Small Square.- Can be short or prolong.

Short Abnormalities:a- Wolf Parkinson White Syndrome (WPW):

I. Short P-R Segment.II. Slurring (Delta wave).

III. Wide QRS

b- Lown Ganong Levine Syndrome (LGL): A-V Sends Impulse DirectlyI. Short P-R segment.

Prolong Abnormalities: (Heart Block), [We look between R-R]a- 1st Degree Delayed Conduction Though the A-V node (All arrive but delayed)

Long PR segment


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b- 2nd Degree Half the impulse arrive and half dontI. Wenckebach (Mobit 1) Progressive (Has specific patterns), gets worse

with each cycle.

II. Mobit 2 2 cycles are normal and 1 abnormal (either 2 or 3 or 4).

c- 3rd Degree (Complete Heart Block), no relation between atrium and ventricle. Very long PR segment.

Also in 3rd degree, In somecases, Heart Devlop an Ectopic Foci.

Ectopic Foci: Ectopic foci are abnormal pacemaker sites within the heart (outside of the SA node) that display automaticity, which can cause additional beats (observed as premature beats) or take over the normal pacemaker


http://www.cvphysiology.com/Arrhythmias/A012.htm



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activity of the SA node. These ectopic pacemakers can lead to either tachycardia or bradycardia.

- Bundle Branch block: Any bundle branch block result in (Wide QRS).1- QRS Complex Abnormalities: related to the ventricle, QRS is normally narrow.

a- Left Ventricular Hypertrophy: We look at V1 = Deep S wave V6 = Tall R wave




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To say the patient is hyper trophic V1+V6 = 35 and above ( we count ‘S’ big Squares Longitudinally, and ‘R’ big squares Longitudinally, each multiplied in 5 then added together)

b- Right Ventricular Hypertrophy: Tall R, we only need to look at V1 and V2.

- Lead Placement:a. Chest Leads:

b. Limb lead + Bipolar Leads( bipolar is connection between 2 leads):


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- Axis Deviation (heart position): we look at Lead1 + AVF (foot) = we look at QRS.a. Left Axis Deviation:

b. Right Axis Deviation:

c. Odd Axis Deviation: Both lead 1 and lead AVF will be pointing downwards.

Lead 1 Lead aVFRight Axis Deviation -ve (pointing downward) +ve (pointing upwards)Left Axis Deviation +ve (pointing upwards) -ve (pointing downward)Odd Axis Deviation -ve (pointing downward) -ve (pointing downward)

- Bundle Branch Block: we look at V1, V6 lead.a. Left Bundle Branch Block (LBBB):


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V1 no R QS pattern.V6 Tall, Wide R looks like M.

b. Right Bundle Branch Block:

V1 M Shape R’ Wide.V6 W shape S Wide.

- Heart Sound:a. First Sound (S1) Mitral and Tricuspid closure In isovolumetric Systole.b. Second Sound (S2) Aortic and Pulmonary closure In Diastole.c. Third and fourth Sound (S3, S4) Pathological

I. Third Sound (S3): Rapid ventricular filling, present in heart failure.


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II. Fourth Sound (S4): Late diastole, associated with Atrium Hypertrophy Contraction.

d. Opening Snap Mitral Stenosis in Diastole.e. Pericardial Knock TB in PeriCardium in Diastole.f. Systolic Ejection Click Aortic stenosis in Systole.g. Mid Systolic click Mitral vavle prolapse in Systole.h. Metalic Click Prosthetic valve closure.i. Split and Fixed Atrium septal defect.

- All Added sounds are heard in Diastole.- Arrhythmia : Disterbance of heart beat in conduction or impulse or both.- Any arrhythmia we should :

1. Regularity.2. QRS.3. Rate.

- TachyCardia > 100a. Regular:

I. Narrow QRS: Supra-Ventricular: Origin of conduction

i. SA node P wave.ii. Atrium Ectobic Foci P-Wave Morphology.

iii. A-V Node if main conduction is from A-V No P Wave.iv. Atrium Flatter HR=300 Saw tooth appearance.

Treatment: Hemodynamic Stability (BP):If stable Base maker + Medication.If not stable Shock treatment.

II. Wide QRS:i. SA node Normal P wave.

ii. A-V node Bundle Branch Block and Ectobic Foci.iii. Atrium Flatter Bundle Branch Block and Ectobic Foci.

b. Irregular:I. Aterial Fibrilation= 600

II. Ventricular Fibrilation = 600III. Treatment: Cardioversion:

If stable Medications.If not stable Shock.

- In Tachycardia massage to the carotid body will stimulate Vagus Nerve causing Bradycardia.- All Arrhythmia we use Synchronized Shock Treatment ( Shock After QRS complex) except Ventricular

Treatment no need, Caused no QRS complex in VF.- Bradycardia:


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a. Regular:I. QRS Narrow:

i. SA node P Wave Present.ii. A-V node Mobit 2

iii. IdioVentrecular Ectobic Foci in ventricle 3rd degree.

II. QRS Wide: Bundle Branch Block or Ectobic Foci.b. Irregular:

I. AFII. AV

III. Treatment: Medication.- Approach to Cardiac Patient:- Symptoms of Heart Disease:

1. Chest pain2. Dyspnea3. Palpitation4. Syncope5. Fatigue 6. Peripheral Oedema

- Central Chest Pain: Pain of Angina Pectoris and Myocardial Infarction Due to myocardial Hypoxia.

a. Angina Retro-sternal heavy or gripping sensation, with radiation to left or neck.Provoked by Exertion, eased by rest of niterates.

b. Acute Coronary Syndrome Similar to Angina pain but at rest.c. Aortic Dissection Severe tearing chest pain, radiating to the back.

d. Pericarditis pain sharp central chest pain, worse when moving or respirating.Relieved by sitting forward.

e. Da Costa’s Syndrome Sharp, stabbing, left sub-mammary pain.Associated with anexity.

- Dyspnea: caused by Left ventricular failure, due to Oedema of pulmonary interstitium and alvioli. a. Orthopnea Breathlessness on laying flat.b. Parpxysmal nocturnal dyspnea Patient wakes from sleep fighting for breath.

c. Cheyne-stokes respiration Hyper ventilation + alternating episodes of apnea Heart failure.

d. Central sleep apnea syndrome (CSAS) hypopnea and apnea together called “Periodic breathing”.

- Syncope: loss of consciousness, due to inadequate cerebral blood flow.a. Vascular:


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I. Vasovagal attack simple Faint (most Common).II. Postural (Orthostatic) hypotension drop of systolic pressure within 2

hours of eating.III. Micturition syncope loss of consciousness while passing urine.IV. Carotid sinus syncope when there is exaggerated vagal response to

carotid sinus stimulation, aggravated by wearing tight collar or looking upwards or turning the head.

b. Obstructive: due to restriction of blood flow from the heart to the rest of the circulation, or between the heart champers.

c. Arrhythmias: stokes-adam attacks sudden loss of consciousness, unrelated to posture, pulse usually slow or absent.

- Fatigue: inadequate systemic perfusion of heart failure, due to poor sleep or direct side effect of medication: a. beta-blocker. b. electrolytic imbalance.

- Periphral Oedema: heart failure result in salt and water retention, which lead to dependent pitting Oedema.

- Palpitation: increase awareness of normal heart beat or sensation of slow, rapid or irregular heart rhythms:

a. Pre-mature beats: pause followed by forceful beat.b. Paroxysmal tachycardias: Sudden racing heart beats.c. Brady Cardias: slow, regular, heavy or forceful beats.


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Understanding ECG