Presentation on theme: "Remove the Mystery from 12 Lead EKG Interpretation for Acute MI"— Presentation transcript:
1Remove the Mystery from 12 Lead EKG Interpretation for Acute MI The simple, rapid “12 lead solution” to 12 lead confusion!A 12 Lead Program for ALL health care professionals!Copyright Apex Innovations 2003
2The Basics….. Let’s do the re-view Coronary AnatomyConductionPaper and rate basicsRhythmLead placementVectors and axisR wave progression
3Coronary Anatomy Aorta Circumflex (Cx) Right Coronary Artery (RCA) Left AnteriorDecending (LAD)
4Constant, Continuous Conduction….the beat goes on Normal P-QRS-TConstant, Continuous Conduction….the beat goes onQRS..VentriculardepolarizationP waveDepolarization &contraction ofboth atriaIso-electric LineT wave…Ventricularrepolarization
5Constant, Continuous Conduction….the beat goes on Normal P-QRS-TConstant, Continuous Conduction….the beat goes onR-Upward slopeS-Down slopeIso-electric LineQ-First down slope
6Normal P-QRS-T P Wave PR Interval QRS Complex ST Segment Represents AtrialdepolarizationTime between onset of atrial depolarization and onset of ventricular depolarization(AV conduction time)Ventricular depolarizationInterval between ventricular depolarization and repolarizationDuration< 0.12 secondssecondssecondsMeasure from end of QRS toJ-point, the beginning of T waveHeight< 2.5 mmMeasure start of P waveto start of QRSQ- First negativedeflectionR- First positiveS- Negative deflectionafter R waveShapeSmoothProlonged indicates a conduction blockShortened indicates accelerated conduction or junctional in originIn relation to iso-electric line:Depression/Negative indicates ischemiaElevation/Positive indicates injuryOrientationPositive in Leads I,II,aVF, V4Negative in aVR
7Cardiac Conduction System Sinus nodeInternodalpathwaysAV nodeLeftBundleBranchBundle of HisRightBundleBranchPurkinjefibers
8Cardiac Conduction System Relationship of ECG to anatomy
9Rate: EKG Paper BasicsStandard paper speed = 25mm per second Note calibration on side of EKG - 2 Large Blocks tallOne small Block = 1mm VoltageOne Small Block = .04 SecondsOne Large Block = 5mm VoltageOne Large Block = .20 Seconds-Increased paper speed makes complexes wider -Decreased paper speed makes the complexes narrower
10Rate: Calculation Options RATE = # of R waves in a 6 second strip X 10RATE = 300 # large squares between R wavesRATE Count = Count from a QRS complex on any bold line to the next QRS complex. Count “300, 150, 100, 75, 60, 50” for each bold line after first complex.StartEndRate = 82 BPM
15Rhythms Continued AV Blocks 1 Prolonged PRI 2 Type I - Wenchebach 2 Type II - Mobitz II- 2:1, 3:1 Conduction3 Complete Heart BlockBundle Branch- Right BB- Left BB
16The 12 Lead EKG… 12 angles or pictures of the electrical activity of the heart6 Limb Leads6 Chest or Pre-cordial LeadsIIIIIIAVRAVLAVFV1V2V3V4V5V6
17Looking and Learning: Vectors and Axis ~the hard way~ The sum of all vectors determines the axisA panoramic viewof the heart’selectrical activity from12 different angles
18Lead Placement - Lead I, II, III LEAD I Bipolar Limb LeadLooks from Right to Left ShoulderLooks at high lateral wall ofleft ventricleSupplied by circumflex artery–CXPositive/upright P QRS T-RA+LALL
19Lead Placement - Lead I, II, III LEAD II Bipolar Limb LeadLooks from R Shoulder to Left LegLooks at inferior wall of left ventricleSupplied by right coronary artery–RCAPositive/upright P QRS T-RA+LA-+LL
20Lead Placement - Lead I, II, III LEAD III Bipolar Limb LeadLooks from Left Shoulder to Left LegLooks at inferior wall of left ventricleSupplied by right coronary artery-RCAA biphasic QRS complex is expected-RA+LA--++LL
21Augmented Limb Leads AVR AVL Augmented Voltage Left Arm AVF Augmented Voltage Right ArmAll complex waves are negativeTypically, this lead not used for diagnosing!AVLAugmented Voltage Left ArmLooks at lateral wall of left ventricleSupplied by circumflex artery - CXAll complexes should be positiveAVFAugmented Voltage (left) FootCross between Leads I and IILooks at inferior wall of left ventricleSupplied by right coronary artery-RCARALA+++LL
22Lead Placement – V-Leads V1-V2 = SeptalV3-V4 = AnteriorV5-V6 = LateralV1-V3 = PosteriorV1 – 4th ICS, right of sternumV2 – 4th ICS, left of sternumV3 – Midpoint between V2 and V4V4 – 5th ICS, mid-clavicular lineV5 – Level with V4 , anterior to axillary lineV6 – Level with V4, mid-axillary line
23V-Lead R Wave Progression The progression or increasing in R wave amplitude from negative to positive in leads V1 to V4 is expected and normal!- V1 - R wave is generally smallest or most negative- V4 - R wave is typically the tallest or most positive- Lack of R wave progression may mean :Pathology- Disease state, CAD, Septal wall MINormal- A patient with Congenital state, Rotated heart, Obesity, COPDOther- Breast tissue, poor lead placement
24R Wave Progression in the V Leads V1 – PQRST All negativeV2 – PQRST Should be mostly negative butstart progressionV3 – PQRST Biphasic with upright T wavesV4 – PQRST Nearly completely uprightV5 – PQRST UprightV6 – PQRST Upright
25Myocardial Infarction Bumps, elevations and tombstones…IschemiaInjuryRecognitionCriteriaInfarct Location TemplateAMI EvolutionPractice EKG’s
26Myocardial Infarction Occurs when a coronary artery is narrowed and occludes,terminating the blood and oxygen supply. This results incardiac hypoxia and irritability which may cause fatal arrhythmias.Without a blood supply to the cardiac muscle, depolarizationcannot happen and renders the muscle, electrically dead.An EKG can diagnose AMI location, identify the culpritartery and reveal any blocks inventricular conduction.
27ST Depression = Ischemia Inverted T waves, sometimes peakedT wave deflection is opposite from QRS (Normally T wave is upright when QRS is upright and vice versa)T wave inversion is usually in same leads that demonstrates signs of acute infarction(Q waves, ST elevation)
28Causes for ST depression IschemiaDigoxin ToxicityPulmonary EmbolismVentricular HypertrophyLeft Bundle Branch Block
29ST Elevation = Current Injury Depicts current myocardial injuryMeasure J-point to beginning of ventricular repolarizationMay be elevated >1mm in limb leads and >2mm in precordial leadsWill see reciprocal ST depression in other leads
30Causes for ST elevation PericarditisVentricular aneurysmDrug inducedMyocardial Infarction
31Recognition of AMI Know what to look for: ST elevation >1 mm J pointKnow what to look for:ST elevation >1 mm3 contiguous leadsPR baselineST-segment deviation = 4.5 mm
32AMI Requires at least 2 of these criteria: History of characteristic chest painCrushing-pressure in chest, pain radiation to jaw, arms, back, N/V, SOB, diaphoresisEvolutionary EKG changesST depression (ischemia)ST elevation (injury)Q wave development (muscle death)Elevated cardiac enzymesTroponin, CKMB-CK, Myoglobin
33Understanding infarct location Here’s the trick! The 12 Lead Solutionto12 Lead Confusion!
34Location, Location, Location! Simple - Rapid!!Finally…….Remove the mystery!Location, Location, Location!
35AMI Location Correlation I LateralaVRV1 SeptalV4 AnteriorThis slide illustrates the 3 4 format of the 12-lead ECG.Each box represents 1 lead, and the viewpoint of that lead is indicated.II InferioraVL LateralV2 SeptalV5 LateralIII InferioraVF InferiorV3 AnteriorV6 Lateral
36Lateral Lead ST Elevation in AMI LEAD IAVLV5V6 “High Lateral” Wall Lateral: Usually supplied by Circumflex (CX)Look for reciprocal changes in Lead V1
4412 Lead-Paper Heart To better understand rhythm location: Hold left upper corner andright lower corner of EKGRoll EKG to note:inferior leads at apexlateral leads on sidesanterior and septal leads in front
45Significant Q Wave Characteristics Height is 1/3 the size of entireQRS complexWidth is at least one square or0.04 seconds in durationQ waves in V1,V2,V3 or V4indicate anterior or antero-septal infarctionDamage from old infarcts causeQ waves that last a lifetimeAbnormal if thick on tracingQ wave may be normal in AVR
46ST segment Evolution and Q wave development with AMI
47Differentiating Between Acute and Old MI Q wave with no other morphology = old MIQ wave and ST segment elevation (with or without T wave inversion) = AMIQ wave and inverted T wave = age undetermined
48Evolutional Changes of an Acute Myocardial Infarction
49Identify infarct location using a systematic approach RhythmST DepressionST ElevationR Wave ProgressionQ Waves
50Let’s take a look at… the Good, the Bad and the Ugly! ~EKG Review~
51Review #1 What Does This 12-Lead ECG Show? INFERIORLATERALSEPTALANTERIORINFERIOR
52Review #2 What Does This 12-Lead ECG Show? LATERALANTERIORLATERALSEPTALANTERIORINFERIOR
53Review #3 What Does This 12-Lead ECG Show? LATERALANTERIORLATERALSEPTALANTERIORINFERIOR
54Appearances and History are Important! Your patient, a 58 y/o male, was diagnosed with cancer 2 weeks ago and was scheduled to receive his first chemotherapy treatment this morning. Instead, he was delivered in a wheelchair hurriedly (by his oncologist), to the emergency department in distress. He presents complaining of intense chest pain described as a “10”, is very restless, nauseated, diaphoretic and pale. You order the usual cardiac work-up. Here is what his EKG showed…
55Review #4 What Does This 12-Lead ECG Show? LATERALSEPTALANTERIORINFERIOR
56Later that day…This patient’s cardiac workup returned within normal limits and was diagnosed with anxiety and released to begin his chemotherapy.
57Review #5 What Does This 12-Lead ECG Show? LATERALANTERIORLATERALSEPTALANTERIORINFERIOR
58Review #6 What Does This 12-Lead ECG Show? INFERIORLATERALLATERALSEPTALANTERIORINFERIOR
59Review #7 What Does This 12-Lead ECG Show? LATERALANTERIORLATERALSEPTALANTERIORINFERIOR
60Appearances and History are Important! Your patient, a 62 year old male pharmacist, presents at 6:00AM with chest pressure radiating to his neck, jaw and left arm. He is mildly short of breath and says he’s had indigestion all night. You order the usual cardiac work-up. Here is what his EKG showed…
61Review #8 What Does This 12-Lead ECG Show? LATERALSEPTALANTERIORLATERALSEPTALANTERIORINFERIOR
62Later that day… The Inferolateral/Anteroseptal MI caused massive injury and tissue death,and the patient subsequently died.
63Review #9 What Does This 12-Lead ECG Show? INFERIORLATERALSEPTALANTERIORINFERIOR
64Review #10 What Does This 12-Lead ECG Show? SEPTALLATERALSEPTALANTERIORINFERIOR
65Posterior MI’s can be tricky! EKG changes are seen in V1-V3 (the anterior precordial leads)and are a mirror image of an anteroseptal MIYou will see:Increased R wave amplitude and durationR wave is more prominent than S wave in V1 and V2ST depression and large inverted T waves V1-V3Posterior MI HINT: R waves in V1 and V2?Suspect Posterior MI!
66Review #11 What Does This 12-Lead ECG Show? POSTERIORLATERALSEPTAL?ANTERIORINFERIORANTERIOR?
67Review #12 What Does This 12-Lead ECG Show? Look at those R waves!!! POSTERIORINFERIORLATERALSEPTAL?ANTERIORINFERIORANTERIOR?
69Please stop here! ~Test Time~ Answer the Self Assessment Sheet’s first 8 questions.2. Next proceed to the remainingslides and record the infarct locationfor each EKG on the self assessment.
70Quiz #1 Where is the elevation or infarct? LATERALSEPTALANTERIORINFERIORINFERIOR
71Quiz #2 Where is the elevation or infarct? SEPTALANTERIORLATERALSEPTALANTERIORINFERIOR
72Quiz #3 Where is the elevation or infarct? LATERALLATERALSEPTALANTERIORINFERIOR
73Quiz #4 Where is the elevation or infarct? SEPTALANTERIORLATERALSEPTALANTERIORINFERIORReview the 12-lead ECG.Go lead by lead, and pick one good complex in each lead.Find the J point and ST segment.Compare the ST to the TP segment, looking for 1 mm (1 small box) of elevation (ignore ST depression for now).Place a check mark next to any lead with 1 mm of ST-segment elevation.Localize the area of infarction.
74Quiz #5 Where is the elevation or infarct? LATERALANTERIORLATERALSEPTALANTERIORINFERIOR
75Quiz #6 Where is the elevation or infarct? SEPTALANTERIORLATERALSEPTALANTERIORINFERIOR
76Quiz #7 Where is the elevation or infarct? INFERIORLATERALLATERALSEPTALANTERIORINFERIOR
77Quiz #8 Where is the elevation or infarct? LATERALSEPTALANTERIORLATERALSEPTALANTERIORINFERIOR
78Quiz #9 Where is the elevation or infarct? SEPTALLATERALSEPTALANTERIORINFERIOR
79Quiz #10 Where is the elevation or infarct? LATERALANTERIORINFERIORLATERALSEPTALANTERIORINFERIOR
80Quiz #11 Where is the elevation or infarct? SEPTALANTERIORLATERALSEPTALANTERIORINFERIOR
81Thank you for your participation! Please complete the program and speaker evaluation.Copyright Apex Innovations 2003