Download as PPSX, PPTX
![ECG paper
Speed 25mm/s
• 1 large square= 5 small square [5mm]
Voltage
• 10mm =1mV](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-6-2048.jpg)
![Appearance of waves
• Positive deflection [upward]
• If electrical impulses flowing towards
that lead
• Negative deflection [downward]
• If electrical impulses flowing away from
that lead](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-9-2048.jpg)
![•If HR is irregular
Count no. of QRS complexes in 30 large squares=
6 sec
Multiply it with 10
HR [per min]](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-21-2048.jpg)
![• Right axis deviation [RAD]
• Beyond +90°
• Left Axis Deviation [LAD]
• Beyond -30°](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-31-2048.jpg)
![Method 2
• Quick method
• Identify limb lead in which QRS complex
is isoelectric
• [with equal positive & negative
deflection]
• Implies: electric flow is at Right angle to
this lead](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-38-2048.jpg)
![• Third Degree Block [Complete AV Block]
• No relationship between P waves & QRS
complex](https://image.slidesharecdn.com/howtoreadecg-130901100253-phpapp02/75/How-to-read-ECG-63-2048.jpg)
Uploaded bySatyanarayana Naidu
How to read ECG
The document provides information on how to read and interpret an electrocardiogram (ECG). It discusses the components of an ECG including the leads, waves, intervals and segments. It describes how to analyze key aspects such as heart rate, rhythm, axes, hypertrophy, blocks, and abnormalities. The systematic 14-point approach involves analyzing standardization, rate, rhythm, P waves, intervals, voltages, axes, and segments to interpret the ECG and identify any pathological conditions.
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How to read ECG
- 1. How to readECG
- 2. ECG • Representation ofElectrical activity of heart
- 4. ECG Leads • 12lead ECG • 6 limb leads: Lead I, II, III aVL, aVR, aVF • 6 Chest Leads: V1, V2,V3, V4, V5, V6
- 6. ECG paper Speed 25mm/s •1 large square= 5 small square [5mm] Voltage • 10mm =1mV
- 9. Appearance of waves •Positive deflection [upward] • If electrical impulses flowing towards that lead • Negative deflection [downward] • If electrical impulses flowing away from that lead
- 15.
- 16. P wave Atrialdepolarization PR interval Atrial depolarization to start of ventricular depolarization QRS complex Ventricular depolarization T wave Ventricular repolarization QT interval Ventricular depolarization & repolarization U wave ? Interventricular septal repolarization
- 17. Systematic approach • Thefollowing 14 points should be analyzed carefully in every ECG: • Standardization • Heart rate • Rhythm • P waves • PR interval • QRS voltages • QRS interval • QT interval • Mean QRS axis • Precordial R-wave progression • Abnormal Q waves • ST segments • T waves • U waves
- 18.
- 19.
- 21. •If HR isirregular Count no. of QRS complexes in 30 large squares= 6 sec Multiply it with 10 HR [per min]
- 22. Rate calculation • Memorizethe number sequence: 300, 150, 100, 75, 60, 50
- 23. • ECG machines:print out HR • DO NOT RELY ON IT!!!! • Always Calculate yourself. • Bradycardia: <60/min • Tachycardia: >100/min
- 24. Rhythm • Rhythm strip:prolonged recording of Lead II • Sinus rhythm ? • Each QRS complex preceded by P wave • Regular/ irregular?
- 25.
- 26.
- 27. QRS AXIS • Indicatorof overall direction that wave of depolarization takes when passing through ventricles • Also called ANGLE • Measured • in degrees
- 28.
- 31. • Right axisdeviation [RAD] • Beyond +90° • Left Axis Deviation [LAD] • Beyond -30°
- 34. Method 1 • Mostprecise method • Use of vectors • Measure overall height of QRS in lead I & aVF • Plot in graph paper • Measure the ANGLE of vector
- 38. Method 2 • Quickmethod • Identify limb lead in which QRS complex is isoelectric • [with equal positive & negative deflection] • Implies: electric flow is at Right angle to this lead
- 40. Method 3 • Forquick assessment • Look at QRS complexes in lead I & II
- 41. • Predominantly positive QRSin lead I • Axis between -90 to +90 • Excludes RAD
- 42. • Predominantly positive QRSin lead II • Axis between -30 to +150 • Excludes LAD
- 43. Lead I LeadII Cardiac Axis QRS Positive QRS Positive Normal Axis QRS Positive QRS Negative Left Axis Deviation QRS Negative QRS Positive Right Axis Deviation
- 44. • LAD • WPWsyndrome • LBBB • Inferior wall MI • RAD • RVH • WPW syndrome • Anterolateral MI • Dextrocardia
- 45. P wave • Presentor not? • Sinus rhythm • If completely absent •Atrial Fibrillation •Hyperkalemia • If intermittently absent •Sinus arrest
- 48. • Inverted Pwaves? • Incorrect positioned electrodes • Dextrocardia • Abnormal atrial depolarization
- 49. • Height ofP waves • > 2.5 mm: tall • Indicative of Right Atrial enlargement • P Pulmonale
- 51.
- 52. • Width ofP waves • >2mm width: abnormal • Bifid P wave • Indicates Left Atrial enlargement • P Mitrale
- 55. PR Interval • Fromstart of P wave to start of R wave • Normally • Not <3 small squares • Not > 5 small squares • Consistent
- 56. Short PR Interval •AV junctional rhythm • WPW syndrome • Lown –Ganong-Levine syndrome
- 57. Long PR Interval •Denotes delay in conduction through AV node • First Degree Block • PR prolonged, constant
- 59. Second degree Block •Mobitz Type I • PR progressively increase until one P wave fails to produce QRS complex
- 61. • Mobitz TypeII • PR interval normal & fixed, • But occasional P waves fail to produce QRS
- 63. • Third DegreeBlock [Complete AV Block] • No relationship between P waves & QRS complex
- 64. • 2:1 Block •Alternate P waves are not followed by QRS complex
- 65. Q WAVE • Firstnegative deflection in QRS complex • ? Pathological Q waves • If • >2 small squares deep • >1 small square wide • >25% of height of the following R wave in depth
- 66. QRS complex • Appearanceof QRS Complex vary from lead to lead
- 67. • Width: Narrow/wide • Wide QRS: • > 3 small squares • Bundle branch block • Ventricular arrhythmia
- 68. • Size ofQRS complex • Small: • Pericardial effusion • ?incorrect calibration
- 69. • Big QRScomplex • Ventricular hypertrophy: R/L • WPW syndrome
- 70. Progression of Rwave • V1: small R wave , large S wave, • Gradually R wave increases, S wave decreases • V6: small Q wave, large R wave • V3 and V4 : located midway between V1 and V6, QRS complex nearly isoelectric in one of these leads
- 71. Progression of Rwave
- 72. Left ventricular Hypertrophy •R Wave in V5 or V6 >25mm • S Wave in V1 or V2 > 25mm • Sum of R wave in V5 Or V6 & S wave in V1 or V2 >35mm
- 74.
- 75. Right Ventricular Hypertrophy •Right axis deviation • Deep S Waves in leads V5 & V6 • R>S in V1 • RBBB
- 78. RBBB • Right BundleBranch Block • Broad QRS complex • Small r wave in V1, small Q wave in V6 • S wave in V1, R wave in V6 • R‟ wave in V1, S wave in V6
- 81. LBBB • Left BundleBranch Block • Broad QRS • Small Q wave in V1, Small r wave in V6 • R wave in V1, S wave in V6 • S wave in V1, R‟ wave in V6
- 84. • “WILLIAM MORROW” •William: „W‟ in V1 & „M‟ in V6: LBBB • Morrow: „M‟ in V1 & „W‟ in V6: RBBB
- 86. • LBBB • IschemicHeart Disease • Cardiomyopathy • LVH • Fibrosis • RBBB • Ischemic heart disease • Cardiomyopathy • ASD • Massive pulmonary embolism
- 87. ST Segment • Fromend of S wave to start of T Wave • Normally: Isoelectric • ? Depressed/ elevated
- 90. • Elevated STsegment • Acute MI • Prinzmetal’s angina • Pericarditis • LV aneurysm • High take off
- 96. • Depressed STsegment • Myocardial ischemia • Posterior MI • Ventricular hypertrophy with ‘Strain’ • Drugs: Digoxin
- 98. Ventricular Hypertrophy with “strain”pattern • Tall R waves • Deep S waves • ST segment depression • T wave inversion
- 100.
- 101. T wave • Inverted? •Normal in aVR • V1,V2, III • Size • Normal: not > ½ size of preceeding QRS complex • Too small? • Too large?
- 102. Tall T waves •Hyperkalemia • Acute MI
- 105. Too small TWaves • Hypokalemia • Pericardial effusion • hypothyroidism
- 106. Inverted T waves •Normal in few leads: aVR, V1, V2, III • MI • Myocardial ischemia • Ventricular hypertrophy with “strain” • Digoxin toxicity
- 108. QT Interval • Fromstart of QRS complex to end of T wave • Varies with HR
- 109. Corrected QT interval •QTC • QTC =QT/√RR • Normal: 0.35-0.43 sec
- 110. Prolonged QTc • If≥0.44 sec • Hypocalcemia • Acute myocarditis • Torsades de pointes
- 111. U waves • Mostlyin anterior chest leads • Difficult to identify clearly
- 113. • Prominent UWaves • Hypoklemia • Hypercalcemia • Hyperthyroidism
- 114.
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- 119.
- 120.
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- 122.