4/17/2013

1

10 ECGs No Practitioner Can Afford to Miss

Mary L. Dohrmann, MDProfessor of Clinical Medicine

Division of Cardiovascular MedicineUniversity of Missouri School of Medicine

No disclosures

Objectives

1. Review basic principles

2. Have some fun with some ECGs

3. Go home with some motivation

4/17/2013

2

Resources

• Complete Guide to ECGs 3rd ed., 2009, ed. O’Keefe et al: 88 practice ECGs

• Great website for practice http://ecg.bidmc.harvard.edu/maven

Stages of ECG expertise

• Observation

• Observation + conclusion

• Above plus clinical context/application

(takes into account all available information)

4/17/2013

3

What is “Normal”?

‐ Not deviating from a norm, rule, or principle 

‐ Conforming to a type, standard, or regular pattern

The “standard” ECG

– Patient position

– Proper lead locations

– Voltage standardization

– Paper speed

4/17/2013

4

Standard vs Non‐Standard ECG

Standard limb leads

Non‐Standard limb leads

The Normal ECG

4/17/2013

5

The Normal ECG

Sinus rhythm (P before @ QRS)P wave axis (+ I,II,III, aVF) 

Rate 50 – 100 bpm; paper speed 25 mm/secQRS Axis +90o (youth) to –30o (elderly)Intervals: PR .12‐.21 sec, QRS < .10 secQTc <.46 sec (observed QT/√RR interval)

QRS voltage (n/a < age 35)(use 10mV standard)Precordial R waves (transition V3‐V4)

ST segment (baseline or early repolarization pattern)T wave (concordant with frontal plane QRS vector)

Is this person older or younger than pt in prior ECG?

Normal ECG

4/17/2013

6

This ECG is in an older individual than prior normal ECG –why? axis is more leftward!

Normal ECG

Rhythm

Sinus Not sinus

VentricularSupravent.Morphology

4/17/2013

7

Morphology Hierarchy

WPW > LBBB > LVH > MI

1st ECG in ED in patient w/chest pain

4/17/2013

8

Next steps?

A. Get a VQ scan

B. Take the patient to the cath lab

C. Repeat the ECG

D. Get an echo

The R wave progression does not make sense! Negative P and T in V3 are clues that this V3 is really V1.   Note: an isolated Q in III is NORMAL! 

Repeat the ECG:  Reversed V1 and V3 leads

4/17/2013

9

Prior ECG with V lead positions corrected now appears normal!

1st ECG in ED in patient w/chest pain

4/17/2013

10

Next steps?

A. Get a VQ scan

B. Take the patient to the cath lab

C. Repeat the ECG

D. Get a CXR

1st ECG in ED in patient w/chest painPatient with dextrocardia! A CXR would tell you this!

Dextrocardia – negative P wave in lead I; abnormal R wave progression with diminished voltage in V6

4/17/2013

11

Dextrocardia – ECG in same patient as previousCorrected leads for anatomy (purposely 

reversed arm leads and used right‐sided V leads)

Reversed arm leadsnegative P in I, positive P in aVR

4/17/2013

12

Prior ECG with arm leads corrected

29 y/o with chest pain

4/17/2013

13

What would you do?

A. Take the patient to the cath lab

B. Perform thorough cardiac exam (1st)

C. Repeat ECG

D. Obtain a STAT echocardiogram (2nd)

29 y/o with chest pain Diffuse ST elevation c/w pericarditis

Note: PR segment depression

Physical exam findings: 3-component friction rub, tachycardic, fever. Be sure patient does not have Kussmaul’s, pulsus alternans or paradoxus

4/17/2013

14

47 y/o male with chest painAcute inferior MI

41 y/o male with severe SOBExtensive anterior/anterolateral MI

4/17/2013

15

54 y/o male with exertional chest pain

What test would you obtain?

A. Cardiac catheterization

B. Exercise stress test

C. Exercise stress test  combined with imaging

D. Echocardiogram

In a patient with angina and prior infarct, proceeding directly to cardiac catheterization would be the optimal choice; however, you might also want to get an echocardiogram prior to cardiac cath to assess LV function.

4/17/2013

16

54 y/o male with exertional chest painAMI, indeterminate age; RBBB ± LAFB

Cath findings: 100% proximal LAD, 90% D1, 90% D2, 100% mid-RCA; LVEF 25%

40 y/o resuscitated from VF

4/17/2013

17

40 y/o resuscitated from VFBrugada syndrome

This patient received an AICD

Check out this website!

www.brugada.org

4/17/2013

18

34 year old with syncope

What’s next?

A. Admit for cardiac monitoring

B. Obtain electrolytes

C. Review current medications

D. All of the above

4/17/2013

19

34 year old with syncopeLong‐QT syndrome

Calculate the QTc using Basett’s formula: QTcorrected = QTobserved ÷ √RR

Torsades  de pointes

4/17/2013

20

Drugs that can prolong QT

http://www.qtdrugs.org

Insulin‐dependent diabetic with nausea

4/17/2013

21

If you could get one lab test what would it be?

A. Cardiac enzymes

B. ABGs

C. Serum potassium

D. Serum calcium

Hyperkalemia (K=6.0) with peaked T waves

With severe hyperkalemia, QRS and PR intervals widen, flattened P waves, junctional rhythm, progressing to idioventricular rhythm

4/17/2013

22

Resolution of peaked T waves following treatment of hyperkalemia

40 y/o with chest pain & palpitations

4/17/2013

23

The most likely diagnosis is:

A. Right bundle branch block

B. Acute inferior infarct

C. Left bundle branch block

D. Ventricular preexcitation (WPW)

40 y/o with chest pain & palpitationsshort PR/delta wave c/w preexcitation

4/17/2013

24

WPW mimicking anterior infarct

WPW mimicking inferior infarct (The inferior Qs are delta waves!)

4/17/2013

25

48 y/o male with inferior MI 

What is your treatment?

A. IV lidocaine

B. No treatment needed unless symptomatic

C. IV atropine bolus

D. Put in a pacemaker

4/17/2013

26

Accelerated idioventricular rhythm in context of inferior infarct

May represent reperfusion arrhythmia; may be provoked by increased vagal tone and is as an escape rhythm; well tolerated clinically

80 y/o man with syncope

4/17/2013

27

Right bundle branch block & LAD, 2:1 block and/or complete heart block, with ventricular escape 

complexes

This patient needs a pacemaker!

More fun ECGs to review at home!

4/17/2013

28

2nd degree AV block, Type I (Wenckebach)

(Note the gradually increasing PR interval and subsequent non‐conducted P resulting in a greater than 2 second pause)

Atrial flutter 2:1 conduction

4/17/2013

29

Same patient as previous ECG, atrial flutter with variable conduction

Supraventricular tachycardia ?retrograde P, suggests AV nodal reentry;ST depression – cannot exclude ischemia

4/17/2013

30

Junctional tachycardia with retrograde P waves

Wide complex tachycardia = VT !

4/17/2013

31

Multifocal atrial tachycardia(Note multiple P wave morphologies)

51 y/o male with chest painST elevation I, aVL, V2 c/w acute injury/infarct

(Note: reciprocal depression in II, III, aVF)

Patient had 100% occlusion of diagonal branch from the LAD

4/17/2013

32

70 y/o with exertional chest painECG shows LBBB ‐ cannot interpret for 

ischemia or infarct!

LBBB causes false positive exercise imaging! The stress test of choice would be an adenosine sestamibi.

Right bundle branch block, left anterior fasicular block, and first degree AV block 

4/17/2013

33

I love to review ECGs.Contact me at Dohrmannm@health.missouri.edu