2017 EKG Workshop Basic. Family Medicine Review Course Lou Mancano, MD, FAAFP Reading Health System Family and Community Medicine Reading, PA

Transcription

1 2017 EKG Workshop Basic Family Medicine Review Course Lou Mancano, MD, FAAFP Reading Health System Family and Community Medicine Reading, PA

2 Part I - Objectives Discuss a systematic approach to EKG interpretation Explain EKG criteria used to diagnose various cardiac conditions Through case presentations, illustrate cardiac etiologies of some nonspecific symptoms

3 Disclosure The speaker has nothing to disclose

4 EKG Review Theory Rate Rhythm Axis Intervals (PR, QRS, QT) Chamber sizes QRST changes

5 Screening EKGs in Adults (last update July 2012) The USPSTF recommends against screening with resting or exercise electrocardiography (ECG) for the prediction of coronary heart disease (CHD) events in asymptomatic adults at low risk for CHD events. Grade: D Recommendation

6 Screening EKGs in Adults (last update July 2012) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG for the prediction of CHD events in asymptomatic adults at intermediate or high risk for CHD events. Grade: I Statement

7 Theory

8 Limb leads record coronal plane forces Anatomy and EKG Leads Chest leads record transverse plane forces

9 Anatomy and EKG Lead +/- Poles

10 Limb Leads + Lead I When a wave of depolarization moves through the heart toward a lead s positive electrode, there s an upward deflection recorded in that lead; toward the negative electrode, a downward deflection

11 ISOELECTRIC

12 J point - o 180 o 0 + I

13 o 0 o I atria septum SA AV ventricles

14 Waves

15 Intervals

16 Chest (Precordial) Lead Placement

17 Chest (Precordial) Lead Transverse Plane

18 R wave progression

19 Rate

20 Rate with Regular Rhythm rule 5 small boxes (0.04 sec) = 1 large box (0.2 sec) If there is 1 beat/large box [5 beats per second] X 60 sec/minute, then there are (5 X 60) 300 beats/min If there is 1 beat/every 2 nd box [2.5 beats per sec], then there are (2.5 X 60) 150 beats/min Thus, the rule

21 Rate with Irregular Rhythm For irregular rhythms, check the EKG s 3 second markers (15 large boxes). Count the complexes beginning with zero within a 30 large boxes (6 seconds) and multiply by 10 = avg # beats/60 sec. or estimated beats per minute large boxes

22 Rhythm

23 Common Rhythms Regular Sinus rhythm Atrial flutter (with consistent block) AV Nodal Reentrant Tachycardia (AVNRT or PSVT) Junctional rhythm Irregular Atrial fibrillation Atrial flutter (with variable block) Sinus arrhythmia Wandering Atrial Pacemaker Multifocal Atrial Tachycardia Premature beats (PVCs & PACs with and w/o aberrancy)

24 Sinus Rhythm Normal Sinus Rate of 60 to 100 Same P wave Upright P wave in lead II Sinus Bradycardia Rate < 60 Sinus Tachycardia (intrinsic rate of SA node is 100 to 110) Rate >100 SA

25 Sinus Rhythm Rate ~84

26 Consistent block segment Atrial Flutter w/ Consistent Block Consistent block Variable block segment Variable block

27 AV Nodal Re-entrant Tachycardia No definite p waves, rate ~ 150 to 200 and regular w/o variability May see retrograde p waves (seen as pseudo-terminal S waves in II & avf, and pseudo-r in V1), usually narrow QRS

28 Junctional Rhythm

29 Case #1 67 year old male with history of hypertension presented with 1 month of one flight or one-half block DOE. Denied chest pain and the ROS was otherwise negative. Only medication is HCTZ. Physical exam was normal Labs in his chart from 2 months ago show a normal CBC, a mildly abnormal lipid panel, and normal basic chemistries. Pulse Ox 94% on RA

30 Case #1

31 Case #1 Sinus Tachycardia (common causes) Fever Anemia Hypovolemia Heart Failure Anxiety Hyperthyroidism Medications Pulmonary Emboli

32 Irregular Rhythms Atrial fibrillation Atrial flutter w/ variable block Sinus arrhythmia Wandering Atrial Pacemaker Multifocal Atrial Tachycardia Premature beats (PVCs & PACs with and w/o aberrancy)

33 Atrial Fibrillation

34 Atrial Fibrillation

35 Sinus arrhythmia Rate increases with inspiration and decreases with expiration

36 Wandering Atrial Pacemaker

37 Multifocal Atrial Tachycardia Discrete P waves with at least three different morphologies (P wave morphology is generally best seen in leads II, III and V1) An atrial rate of > 100 beats/min is the classic definition (> 90 bpm has been proposed)) The P-P intervals, the P-R duration, and the R-R intervals vary

38 Ventricular Premature Beats (VPBs or PVCs) QRS > 120 ms VPBs have early widened QRS complexes with a bizarre morphology and repolarization abnormalities markedly different from the sinus QRS complexes. A full compensatory pause usually follows the VPB (the interval between the QRS complexes before and after the VPB is 2X the interval of the 2 successive sinus beats).

39 Premature Atrial Beats QRS < 120 ms The interval between the second sinus beat and the ectopic beat is shorter than the interval between the first two sinus beats. The P wave morphology differs from that of the sinus beats. The PR interval differs from that of the sinus beat. Activation of the ventricular myocardium occurs in a normal fashion so the QRS complex is unchanged from that of sinus rhythm.

40 PAC with Aberrancy vs VPB RBBB pattern (rsr ) of the anomalous beats in a right sided monitor lead (V1) An initial deflection similar in the same direction as that of normally conducted beats Identification of a premature P wave Premature P wave rsr = RBBB pattern

41 Case #2 36 year old female with PMH of diabetes mellitus and pernicious anemia presents with fatigue. Further questioning reveals a 12 lb weight loss in the past 3 months. Her glucose diary shows blood sugars ranging from 80 to 200 and a HgbA1c from 4 months ago was 6.9%. Today s in-office fingerstick glucose is 142. Her ROS is otherwise unremarkable.

42 Case #2 Vital signs recorded as BP 136/74 - P 120 RR 20 T 37.4 C. Your exam discovers a faster heart rate, normal lung, abdominal, extremity and HEENT exams. She seems anxious. DTRs are +3 and symmetric. EKG

43 Case #2 Aberrant conduction Rapid Atrial fibrillation at about 160 bpm

44 Atrial Fibrillation Mitral Valve disease Ischemic Heart disease Hypertension Thyrotoxicosis Lone Atrial fibrillation Advanced age Pulmonary Embolus Pericarditis Case #2 Due to new onset of Graves Disease

45 Axis and Intervals

46 QRS Axis

47 QRS Axis

48 QRS Axis

49 Left QRS Axis Deviation Negative 30 to negative 90 degrees Mechanical shifts (elevated diaphragm) LBBB LAHB or LAFB WPW syndrome (sometimes) Inferior wall MI Sometimes LVH

50 Left Axis Deviation - + Axis = -40 degrees (LVH)

51 Wolf-Parkinson-White QRS axis = -32 degrees PR interval = 0.10 s QRS duration = s

52 Right QRS Axis Deviation > degrees to degrees Mechanical shifts (emphysema) RBBB RVH LPHB WPW syndrome Dextrocardia Lateral wall MI Acute right heart strain (massive PE) Children under age 2

53 Right Axis Deviation _ + Axis = +115 degrees (anterolateral MI)

54 Case #3 What is the QRS axis? QRS Axis +110 Does avr then appear as expected? Should avr be closer to isoelectric?

55 Left and right arm limb leads are reversed If negative p wave and negative QRS complex in Lead I, the most common cause is limb lead reversal Lead III is recorded as lead II and vice versa Case #3

56 Intervals PR Intervals and AV Blocks QRS Duration - Bundle Branch Blocks and hemiblocks QT intervals

57 sec **Males < 0.45 sec **Females < 0.46 sec ** - Hyperkalemia - Digitalis ** Some expert opinions do not agree with this QT interval upper limit of normal

58 Atrioventricular Blocks 1 st Degree PR interval > 0.20 seconds 7.5 blocks or 0.3 sec

59 Atrioventricular Blocks 2 nd Degree AV Block Type 1 (Wenckebach) In classic Wenkebach, the PR interval gets longer until a nonconducted P wave occurs. The RR interval of the pause is shorter than the sum of the 2 preceding RR intervals, and the RR interval after the pause is longer than the RR interval before the pause. The block is located in the AV node.

60 2 nd Degree AV Block (Wenkebach) R-R interval after pause longer than R-R interval before pause R-R interval of the pause is shorter than the sum of the 2 R-R intervals before the pause PR intervals lengthen

61 Atrioventricular Blocks 2 nd Degree AV Block (Mobitz Type 2)

62 Atrioventricular Blocks 3 rd Degree AV Block with Junctional Escape Beats 3 rd Degree AV Block with Ventricular Escape Beats

63 QRS Duration Normal is 0.06 to 0.10 sec Bundle Branch Block = 0.12 sec or more Upper limits of normal to just under BBB (0.10 & 0.11 sec) sometimes seen in hemiblocks and with some medications

64 Left Bundle Branch Block

65 Left Bundle Branch Blocks Complete LBBB has QRS > 0.12 sec Terminal forces (2 nd half of QRS) are oriented leftward and posteriorly because the LV is depolarized after the RV Terminal S wave in V1 indicating late posterior forces (QS or rs in V1) Terminal R wave in leads I, avl, V6 indicating late leftward forces Late left ventricular deflection in V6 No Q wave & Monophasic R wave in V6

66 Left Bundle Branch Block rs pattern Terminal S wave in V1 indicating late posterior forces (QS or rs in V1) Terminal R wave in leads I, avl, V6 indicating late leftward forces

67 Left Bundle Branch Block QS pattern Terminal S wave in V1 indicating late posterior forces (QS or rs in V1) Terminal R wave in leads I, avl, V6 indicating late leftward forces

68 Right Bundle Branch Block

69 Right Bundle Branch Block Complete RBBB has QRS > 0.12 sec Terminal forces (2 nd half of QRS) are oriented rightward and anteriorly because the RV is depolarized after the LV Late Ventricular Deflection in V1, rsr variant, indicating late anterior forces, or wide R or qr in V1 Early Ventricular Deflection and wide S wave in V6 Wide terminal S wave in leads I, avl, V6 indicating late rightward forces

70 Right Bundle Branch Block 120 ms qr Late Ventricular Deflection in V1, rsr variant, indicating late anterior forces, or wide R or qr in V1 2-3 Early Ventricular Deflection and wide S wave in V6 Wide terminal S wave in leads I, avl, V6 indicating late rightward forces

71 Left Anterior Fascicular Block I avf

72 Left Anterior Fascicular Block Left Axis Deviation (usually < - 35 degrees) Small Q waves in leads I and avl; S > R waves in leads II, III, and avf QRS duration < 0.12 sec Small Q, Larger R in I & AVL S > R in II, III, AVF Axis < -35 Left QRS Axis Deviation ~ - 40 degrees

73 Left Anterior Fascicular Block Sometimes a deep S wave in V6

74 Left Posterior Fascicular Block I avf

75 Left Posterior Hemiblock Right axis deviation (> +105) S > R waves in leads I and avl Small Q wave in leads II, III, avf QRS duration < 0.12 sec No evidence of RVH

76 Left Posterior Fascicular Block Small R wave (S > R) in lead I and avl Small Q wave in lead II, III, avf Axis +120 Sinus tachycardia, possible anterior infarct, left posterior fascicular block

77 Case #4 52 year old male with hyperlipidemia presents with dizziness and feeling tired for one day. He takes his statin regularly and has no other complaints. His exam reveals normal lung, HEENT, and neurological exams. BP is 126/75. Pulse is 36.

78 Case #4 Diagnosis = 3rd Degree AV Block

79 QT represents ventricular depolarization/repolarization Longer at slower heart rates and shorter at faster heart rates, therefore the QTc (Bazzett s Formula) Shortened by hypercalcemia, hyperkalemia, and digitalis Prolonged by hypocalcemia, hypokalemia, hypomagnesemia, congenital causes, myocarditis, and many medications QT Intervals

80 QT Intervals QTc-interval between 360 msec up to 440 msec was traditionally considered to be normal. Many experts believe 450 msec in males and 460 msec in females are the upper limits of normal. Some consider up to 470 msec to be borderline prolonged, but not prolonged enough to clearly make the prolonged QTc diagnosis. A QTc at or above 470 milliseconds in males or 480 milliseconds in females is clearly prolonged. The average QTc for someone who has prolonged-qt syndrome is 490 milliseconds.

81 Acute Septal Infarct with prolonged QT interval QTc = 0.51 For patients arriving at the ED 30 minutes after chest pain onset, risk for cardiac arrest for patients with a prolonged QTc (0.50) was more than double (odds ratio 2.20) that of patients with a QTC of 0.44, whereas for those arriving at the ED 1.5 hours after chest pain onset, the risk was 79% lower (OR 0.21). Evidence Level B

82 Chamber Sizes

83 Hypertension JNC8 Recommendations Routine tests recommended before initiating therapy include: 12-lead ECG Looking for LVH and Conduction Abnormalities Serum potassium, creatinine, and consider sodium Diabetes screening Cholesterol screening JNC8+Hypertension+laboratory+and+ECG+testing+recommendations&gs_l=serp i j19j msedr c.1.60.serp bqadzlrhujg Evidence Level B

84 Left Atrial Abnormality Delayed broadening of the latter part of the P wave of at least 0.12 sec in leads I or II resulting in a notched P wave A negative > 1 mm X 1 mm P wave deflection in V1 II V1

85 Left Atrial Enlargement

86 Right Atrial Enlargement P wave amplitude >2.5 mm in lead II and/or Positive P wave deflection >1.5 mm in V1 II V1

87 Right Atrial Enlargement

88 Left Ventricular Hypertrophy Increased QRS amplitude Leftward shift in frontal plane QRS axis Delayed intrinsicoid deflection in V6 (time from QRS onset to peak R is > 0.05 sec) Widened QRS/T angle (LV strain pattern) with slow downstroke-rapid upstroke T wave inversion in V5-V6 Evidence of left atrial enlargement

89 Left Ventricular Hypertrophy Sokolow-Lyons indices Height of R wave in avl > 11 mm or S wave in lead V1 plus R wave in either V5 or V6 > 35 mm Cornell s Voltage Criteria S in V3 + R in avl > 20 mm in women S in V3 + R in avl > 28 mm in men Cornell s sensitivity = 51%, specificity = 95%. All EKG criteria are inferior to Echocardiogram for diagnosing LVH

90 Left Ventricular Hypertrophy

91 Right Ventricular Hypertrophy Negative QRS in lead I (S > R) Positive QRS in V1 (R > S) Might have deep S wave in V5 and V6 Right Axis Deviation

92 Right Ventricular Hypertrophy Axis = +122 degrees

93 Case #5 45 year old male presents for a sore throat. On exam, you notice a BP of 152/92. You review BPs on other visits and they consistently range 140 to 160/85 to 98. When you bring this to his attention and recommend an initial hypertensive workup and treatment, he responds, I get nervous in the doctors office. My pressure is always normal when I check it at the local pharmacy. You check an EKG

94 Case #5 Left Ventricular Hypertrophy This patient likely has long-standing hypertension and should be treated

95 QRST Changes

96 ST Segment Depression >1 mm below baseline measured at 0.08 sec after the J point Ischemia Strain pattern Hypokalemia or hypomagnesemia Rate related Digitalis effect Pericarditis Any combination of above

97 ST Segment Depression

98 ST Segment Elevation At least 1 mm (0.1 mv) in limb leads, V4, V5 or V6 At least 2 mm elevation in males (1.5 mm in females) at the V2 and V3 J- point AMI or cardiac contusion LBBB early repolarization ventricular aneurysm Osborne J waves (hypothermia) Prinzmetal s vasospasm pericarditis

99 T Waves

100 T Waves NSTEMI myocarditis pericarditis cerebral T waves

101 HypoKalemia U wave EKG shows a long QT interval, ST depression, low T waves, and TU wave fusion characteristic of hypokalemia U waves are thought to represent repolarization of the papillary muscles or Purkinje fibers

102 Acute Myocardial Infarction ECG diagnosis requires at least 1 mm (0.1 mv) of new ST segment elevation in corresponding anatomical limb leads, V4, V5 or V6 At least 2 mm elevation in males (1.5 mm in females) at the V2 and V3 J-point These elevations must be anatomically contiguous I, avl, V5, V6 = lateral wall V1-V4 = septal/anterior wall II, III, avf = inferior wall True posterior MI pattern (V1-V2) New LBBB in suspicious setting

103 Myocardial Infarction --V3

104

105 Q waves Because the septum depolarizes left to right, small insignificant Q waves are normal in leads I, avl, V5, and V6. Significant Q waves may indicate a myocardial infarction and are 1/4 the height of the QRS complex or 0.04 sec or more wide

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107 Infarct Patterns

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110 Acute Inferior Wall MI

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114 Acute Anteroseptal MI V1-2-3

115 Acute Anteroapical Infarct

116 Acute Anterolateral Wall MI

117 Acute Lateral or High Lateral Infarct ST elevation in lead avl and reciprocal ST depression in leads II, III, and avf

118 Case #6 A 38 year old construction worker is driven from work to your office complaining of sharp chest pain. He denies shortness of breath, nausea, vomiting, or palpitations. He is diaphoretic but was just working outside on a hot day. His exam reveals normal VS, clear lungs, RRR and you describe a III/VI systolic murmur in your note. No gallop. No JVD. You check an EKG

119 Acute Pericarditis

120 References Stein, E. Rapid Analysis of Electrocardiograms. Lippincott, Williams & Wilkins Marriott, H. Practical Electrocardiography. Williams & Wilkins Accessed January t nt/documents/ekg.pdf

121 Thank You