Ecg final pp ts; 19 06-2012

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Basics of ECG

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  • Ecg final pp ts; 19 06-2012

    1. 1. DR. MVN Suresh.AHA Instructor for BLS & ACLS
    2. 2. • A recording of the electrical activity of the heart over time• Gold standard for diagnosis of cardiac arrhythmias• Helps detect electrolyte disturbances (hyper- & hypokalemia)• Allows for detection of conduction abnormalities• Screening tool for ischemic heart disease during stress tests• Helpful with non-cardiac diseases (e.g. pulmonary embolism or hypothermia )
    3. 3.  Leads used:• Limb leads are I, II, II. So called because at one time subjects had to literally place arms and legs in buckets of salt water.• Each of the leads are bipolar; i.e., it requires two sensors on the skin to make a lead.• If one connects a line between two sensors, one has a vector.• There will be a positive end at one electrode and negative at the other.• The positioning for leads I, II, and III were first given by Einthoven, form the basis of Einthoven’s triangle
    4. 4.  Correct Lead placement and good contact Proper earth connection, avoid other gadgets Deep inspiration record of L3, aVF Compare serial ECGs if available Relate the changes to Age, Sex, Clinical history Consider the co-morbidities that may effect ECG Make a xerox copy of the record for future use Interpret systematically to avoid errors
    5. 5.  Bipolar leads record voltage between electrodes placed on wrists & legs (right leg is ground) Lead I records between right arm & left arm Lead II: right arm & left leg Lead III: left arm & left leg
    6. 6. ECG Bipolar Limb Leads- + - -R L R L F + + F 6
    7. 7. ECG Bipolar Limb Leads Standard ECG is recorded in 12 leads Six Limb leads – L1, L2, L3, aVR, aVL, aVF Six Chest Leads – V1 V2 V3 V4 V5 and V6 L1, L2 and L3 are called bipolar leads L1 between LA and RA L2 between LF and RA L3 between LF and LA 7
    8. 8. 8 8
    9. 9. Precardial (chest) Lead Position V1 Fourth ICS, right sternal border V2 Fourth ICS, left sternal border V3 Equidistant between V2 and V4 V4 Fifth ICS, left Mid clavicular Line V5 Fifth ICS Left anterior axillary line V6 Fifth ICS Left mid axillary line 9
    10. 10. TRANSVERSE PLANE 10
    11. 11. ECG Complex
    12. 12. P wavePR IntervalQRS complexST segmentT WaveQT IntervalRR Interval 12
    13. 13. ECG Complex3 distinct waves areproduced during cardiaccyc3 distinct waves areproduced during cardiaccycleP wave caused by atrialdepolarizationQRS complex caused byventriculardepolarizationT wave results fromventricular repolarizationle
    14. 14. SA node -> atrial muscle -> AV node -> bundleof His -> Left and Right Bundle Branches ->Ventricular muscle
    15. 15. ECG ComplexElements of the ECG:• P wave: Depolarization of both atria; • Relationship between P and QRS helps distinguish various cardiac arrhythmias • Shape and duration of P may indicate Atrial enlargement• PR interval: from onset of P wave to onset of QRS • Normal duration = 0.12-2.0 sec (120-200 ms) (3-4 horizontal boxes) • Represents atria to ventricular conduction time (through His bundle) • Prolonged PR interval may indicate a 1st degree heart block• QRS complex: Ventricular depolarization • Larger than P wave because of greater muscle mass of ventricles • Normal duration = 0.08-0.12 seconds • Its duration, amplitude, and morphology are useful in diagnosing cardiac arrhythmias, ventricular hypertrophy, MI, electrolyte derangement, etc. • Q wave greater than 1/3 the height of the R wave, greater than 0.04 sec
    16. 16. ECG ComplexST segment: • Connects the QRS complex and T wave • Duration of 0.08-0.12 sec (80-120 msecT wave: • Represents Repolarization or recovery of ventricles • Interval from beginning of QRS to apex of T is referred to as the absolute refractory periodQT Interval: • Measured from beginning of QRS to the end of the T wave • Normal QT is usually about 0.40 sec • QT interval varies based on heart rate
    17. 17. 17 ECG Graph Paper X-Axis represents time - Scale X-Axis – 1 mm = 0.04 sec Y-Axis represents voltage - Scale Y-Axis – 1 mm = 0.1 mV Runs at a paper speed of 25mm/sec One big square on X-Axis = 0.2 sec (big box) Two big squares on Y-Axis = 1 milli volt (mV) Each small square is 0.04 sec (1 mm in size at a speed of 25mm/sec) Each big square on the ECG represents 5 small squares = 0.04 x 5 = 0.2 seconds 5 such big squares = 0.2 x 5 = 1sec = 25 mm One second is 25 mm or 5 big squares One minute is 5 x 60 = 300 big squares 17
    18. 18. 18QRS Next QRS 18
    19. 19. No. of Big R – R Interval Rate Rate T Boxes Cal. A C One 0.2 sec 60 0.2 300 H Y Two 0.4 sec 60 0.4 150 N Three 0.6 sec 60 0.6 100 O R Four 0.8 sec 60 0.8 75 M A Five 1.0 sec 60 1.0 60 L B Six 1.2 sec 60 1.2 50 R A Seven 1.4 sec 60 1.4 43 D Y Eight 1.6 sec 60 1.6 37 19
    20. 20. 20Answer on next slide 20
    21. 21.  To find out the heart rate we need to know  The R-R interval in terms of # of big squares  If the R-R intervals are constant In this ECG the R-R intervals are constant R-R are approximately 3 big squares apart So the heart rate is 300 3 = 100 21
    22. 22. 22Answer on next slide 22
    23. 23.  To find out the heart rate we need to know  The R-R interval in terms of # of big squares  If the R-R intervals are constant In this ECG the R-R intervals are constant R-R are approximately 4.5 big squares apart So the heart rate is 300 4.5 = 67 23
    24. 24. 24Answer on next slide 24
    25. 25.  To find out the heart rate we need to know  The R-R interval in terms of # of Big Squares  If the R-R intervals are constant In this ECG the R-R intervals are not constant R-R are varying from 2 boxes to 3 boxes It is an irregular rhythm – Sinus arrhythmia Heart rate is 300 2 to 3 = 150 to 100 approx 25
    26. 26. 26NW NESW SE 26
    27. 27.  The QRS electrical (vector) axis can have 4 directions Normal Axis - when it is downward and to the left – southeast quadrant – from -30 to +90 degrees Right Axis – when it is downward and to the right – southwest quadrant – from +90 to 180 degrees Left Axis – when it is upward and to the left – Northeast quadrant –from -30 to -90 degrees Indeterminate Axis – when it is upward & to the right – Northwest quadrant – from -90 to +180 27
    28. 28. 28 ALL UPRIGHT MEET LEAVE NORMAL RIGHTLEFT 28
    29. 29. Axis LI LIII aVF TIP Normal Positive Positive Both Up Right Negative Positive Meet Left Positive Negative LeaveIndeterminae Negative Positive Meet 29
    30. 30. 30 What is the Axis ?LEAD 1 aVRLEAD 2 aVLLEAD 3 aVF 30
    31. 31.  Note the QRS voltages are positive and upright in the leads - L1, L2, L3 and aVF L2, L3 and aVF tell that it is downward L1, aVL tell that it is to the left Downward and leftward is Normal Axis Normal QRS axis 31
    32. 32. 32 What is the Axis ?LEAD 1 aVRLEAD 2 aVLLEAD 3 aVF 32
    33. 33.  Note the QRS voltages are positive and upright in leads L1and aVL Negative in L2, L3 and aVF L1, aVL tell that it is leftward L2, L3, and aVF tell that it is not down ward - instead it is upward Upward and Leftward is Left Axis See the Left - Leave criterion QRS in L1 and L3 leave each other Left Axis Deviation - LAD 33
    34. 34. 3434
    35. 35.  Standardization – 10 mm (2 boxes) = 1 mV Double and half standardization if required Sinus Rhythm – Each P followed by QRS, R-R constant P waves – always examine for in L2, V1, L1 QRS positive in L1, L2, L3, aVF and aVL. – Neg in aVR QRS is < 0.08 narrow, Q in V5, V6 < 0.04, < 3 mm R wave progression from V1 to V6, QT interval < 0.4 Axis normal – L1, L3, and aVF all will be positive ST Isoelectric, T waves ↑, Normal T↓ in aVR,V1, V2 35
    36. 36. 3636
    37. 37.  This is the ECG of a 6 year old child Heart rate is 100 – Normal for the age See V1 + V5 R >> 35 – Not LVH – Normal T↓ in V1, V2, V3 – Normal in child Base line disturbances in V5, V6 – due to movement by child 37
    38. 38. 38
    39. 39. 39 Normal Resting ECG – cannot exclude disease Ischemia may be covert – supply / demand equation Changes of MI take some time to develop in ECG Mild Ventricular hypertrophy - not detectable in ECG Some of the ECG abnormalities are non specific Single ECG cannot give progress – Need serial ECGs ECG changes not always correlate with Angio results Paroxysmal events will be missed in single ECG 39
    40. 40.  May have slight left axis due to rotation of heart May have high voltage QRS – simulating LVH Mild slurring of QRS but duration < 0.09 J point depression, early repolarization T inversions in V2, V3 and V4 – Juvenile T ↓ Similarly in women also T↓ Low voltages in obese women and men Non cardiac causes of ECG changes may occur 40
    41. 41. Normal Variations in ECG
    42. 42. This ECG has all normal featuresThe ST-T (J) Junction point iselevated. T waves are tall, May be inverted in LIII, The STsegment initial portion is concave. This does not signify Ischemia 42
    43. 43. 43 T↓ BeforeChest pain T↑ DuringChest pain T↓Chest pain Relieved 43
    44. 44. 44 44
    45. 45. 45 45
    46. 46. 46P wave duration is 4 boxes-0.04 x 4 = 0.16 46
    47. 47.  Always examine V 1 and Lead 1 for LAE Biphasic P Waves, Prolonged P waves P wave 0.16 sec, ↑ Downward component Systemic Hypertension, MS and or MR Aortic Stenosis and Regurgitation Left ventricular hypertrophy with dysfunction Atrial Septal Defect with R to L shunt 47
    48. 48. 48 48
    49. 49. 49P wave voltage is 4 boxes or 4 mm 49
    50. 50.  Always examine Lead 2 for RAE Tall Peaked P Waves, Arrow head P waves Amplitude is 4 mm ( 0.4 mV) - abnormal Pulmonary Hypertension, Mitral Stenosis Tricuspid Stenosis, Regurgitation Pulmonary Valvular Stenosis Pulmonary Embolism Atrial Septal Defect with L to R shunt 50
    51. 51. 51 Ventricular Muscle Hypertrophy QRS voltages in V1 and V6, L 1 and aVL We may have to record to ½ standardization T wave changes opposite to QRS direction Associated Axis shifts Associated Atrial hypertrophy 51
    52. 52. 52 52
    53. 53.  Tall R in V1 with R >> S, or R/S ratio > 1 Deep S waves in V4, V5 and V6 The DD is RVH, Posterior MI, Anti-clock wise rotation of Heart Associated Right Axis Deviation, RAE Deep T inversions in V1, V2 and V3 Absence of Inferior MI 53
    54. 54. 54Is there any hypertrophy ? 54
    55. 55. Criteria and Causes of RVHCriteria of RVH Tall R in V1 with R >> S, or R/S ratio > 1 Deep S waves in V4, V5 and V6 The DD is RVH, Posterior MI, Rotation Associated Right Axis Deviation, RAE Deep T inversion in V1, V2 and V3Cause of RVH Long standing Mitral Stenosis Pulmonary Hypertension of any cause VSD or ASD with initial L to R shunt Congenital heart with RV over load Tricuspid regurgitation, Pulmonary stenosis 55
    56. 56. 56What is in this ECG ? 56
    57. 57.  Classical changes seen are Right ventricular hypertrophy Right axis deviation Right Bundle Branch Block P – Pulmonale - Right Atrial enlargement P – Mitrale – Left Atrial enlargement If Atrial Fibrillation develops – „P‟ disappears 57
    58. 58. 58 58
    59. 59.  High QRS voltages in limb leads R in Lead I + S in Lead III > 25 mm S in V1 + R in V5 > 35 mm R in aVL > 11 mm or S V3 + R aVL > 24 , > 20 Deep symmetric T inversion in V4, V5 & V6 QRS duration > 0.09 sec Associated Left Axis Deviation, LAE Cornell Voltage criteria, Estes point scoring 59
    60. 60. 60What is in this ECG ? 60
    61. 61. Causes and Criteria of LVHCauses of LVH Pressure overload - Systemic Hypertension, Aortic Stenosis Volume overload - AR or MR - dilated cardiomyopathy VSD - cause both right & left ventricular volume overload Hypertrophic cardiomyopathy – No pressure or volume overloadCriteria of LVH High QRS voltages in limb leads R in Lead I + S in Lead III > 25 mm or S in V1 + R in V5 > 35 mm R in aVL > 11 mm or S V3 + R aVL > 24 , > 20 Deep symmetric T inversion in V4, V5 & V6 QRS duration > 0.09 sec, Associated Left Axis Deviation, LAE 61
    62. 62. 62APC APC APC APC 62
    63. 63. Atrial Ectopics Note the premature (ectopic) beats marked as APC (Atrial Premature Contractions) These occurred before the next expected QRS complex (premature) Each APC has a P wave preceding the QRS of that beat – So impulse has originated in the atria The QRS duration is normal < 0.08, not wide 63
    64. 64. 66 66
    65. 65. 67 67
    66. 66.  Complete LBBB has a QRS duration > 0.12 sec Prominent S waves in lead V1, R in L I, aVL, V6 Usually broad, Bizarre R waves are seen, M pattern Poor R progression from V1 to V3 is common. The "normal" ST-T waves in LBBB should be oriented opposite to the direction of the QRS Incomplete LBBB looks like LBBB but QRS duration is 0.10 to 0.12 sec, with less ST-T change. This is often a progression of LVH changes. 68
    67. 67. 69RCA LCX LAD RCA LCA 69
    68. 68.  Heart has four surfaces Anterior surface – LAD, Left Circumflex (LCx) Left lateral surface – LCx, partly LAD Inferior surface – RCA, LAD terminal portion Posterior surface – RCA, LCx branches Rt. and Lt. coronary arteries arise from aorta They are 2.5 mm at origin, 0.5 mm at the end Coronary arteries fill during diastole Flow - epicardium to endocardium – poverty/plenty 70
    69. 69. 71 1. Ischemia produces STMyocardial segment depression withIschemia or without T inversion 2. Injury causes ST segment elevation with or withoutMyocardial loss of R wave voltage Injury 3. Infarction causes deep Q waves with loss of RMyocardial wave voltage.Infarction 71
    70. 70. 72TRANSMURAL Injury ST Elevation 72
    71. 71. Blood supply Sub- Transmural endocardial Ischemia Stable VariantTransient loss Angina Angina Infarction NSTEMI STEMIPersistent loss ACS ACS ST Segment Depressed Elevated 73
    72. 72. 74Interpret this ECG 74
    73. 73. Non ST ↑ MI or NSTEMI, Non Q MI Or also called sub-endocardial Infarction Non transmural, restricted to the sub- endocardial region - there will be no ST ↑ or Q waves ST depressions in anterio-lateral & inferior leads Prolonged chest pain, autonomic symptoms like nausea, vomiting, diaphoresis Persistent ST-segment ↓even after resolution of pain 75
    74. 74. 76What are these ECGs 76
    75. 75. STEMI and QWMI ST ↑ signifies severe transmural myocardial injury – This is early stage before death of the muscle tissue – the infarction Q waves signify muscle death – They appear late in the sequence of MI and remain for a long time Presence of either is an indication for thrombolysis 77
    76. 76. 78A – Normal ST segment and T wavesB – ST mild ↑ and prominent T wavesC – Marked ST ↑ + merging upright TD – ST elevation reduced, T↓,Q startsE – Deep Q waves, ST segment returning to baseline, T wave is invertedF – ST became normal, T Upright, Only Q+ 78
    77. 77. 79 79
    78. 78. 80 Notice the smallNormal Q in Lead I 80
    79. 79. 81Notice the deep & wide Infarction Q in Lead I 81
    80. 80. 82Very Striking 82
    81. 81.  Note the hyper acute elevation of ST The R wave is continuing with ST and the complexes are looking rectangular Some times tall and peaked T waves in the precardial leads may be the only evidence of impending infarct Sudden appearance LBBB indicates MI MI in Dextro-cardia – right sided leads are to be recorded 83
    82. 82.  Note the hyper acute elevation of ST The R wave is continuing with ST and the complexes are looking rectangular Some times tall and peaked T waves in the precardial leads may be the only evidence of impending infarct Sudden appearance LBBB indicates MI MI in Dextro-cardia – right sided leads are to be recorded 84
    83. 83. 85Severe Chest Pain – Why ? 85
    84. 84.  Note the marked ST elevations in chest leads V2 to V5 and also ST↑ in L1 & aVL T inversions have not appeared as yet R wave voltages have dropped markedly in V3, V4, V5 and V6 Small R in L1 and aVL. 86
    85. 85. 87Which wall MI ? 87
    86. 86. 88 88
    87. 87.  Due to occlusion of the distal Left circumflex artery or posterior descending or distal right coronary artery Mirror image changes or reciprocal changes in the anterior precardial leads Lead V1 shows unusually tall R wave (it is the mirror image of deep Q) V1 R/S > 1, Differential Diagnosis - RVH 89
    88. 88.  What is the rhythm?
    89. 89.  What is the rhythm?
    90. 90. Ectopic rate nomenclature:[150-250] Paroxysmal tachycardia[250-350] Flutter[350+] Fibrillation
    91. 91.  What is the rhythm?
    92. 92.  What is the rhythm?
    93. 93. Monomorphic VT
    94. 94. Polymorphic VTV1
    95. 95. “Torsade de Pointes”(Polymorphic VT Associated withProlonged Repolarization)
    96. 96. Ventricular Fibrillation (VF) • Totally chaotic rapid ventricular rhythm • Often precipitated by VT • Fatal unless promptly terminated (DC shock)
    97. 97. Sustained VT: Degeneration to VF
    98. 98. Atrial Fibrillation with RapidConduction ;Via AccessoryPathway: Degeneration to VF
    99. 99. In commonRepresentation in culture:• In TV medical dramas, an isoelectric ECG (no cardiac electricalactivity, aka, flatline, is used as a symbol of death or extrememedical peril.• Technically, this is known as asystole, a form of cardiac arrest,with a partcularly bad prognosis.• Defibrillation, which can be used to correct arrythmias such asventricular fibrillation and pulseless ventricular tachycardia,cannot correct asystole.
    100. 100. To summarize: 1. Calculate RATE 2. Determine RHYTHM 3. Determine QRS AXIS 4. Calculate INTERVALS 5. Assess for HYPERTROPHY 6. Look for evidence of INFARCTION
    101. 101. Dr.M.V.N.Suresh<drsuresh10k@gmail.com> Ph: 99 851 9999 3, 988 535 7848

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