ECG Interpretation for the

College Health Practitioner

Donald F. Kreuz, MD, FACC

Columbia University
 Discuss basic ECG findings.

 Explain high risk findings on ECG.

 Identify ECG findings.

 Conditions that predispose to sudden cardiac death
 Arrhythmias most commonly seen in the college
population
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 ECG Findings
Lead I
 QRS in Lead I
 Negative (RAD)
 P wave in Lead I
 Negative
 R Waves Precordial
 Normal progression
Precordial Leads

 Reversed Arm Leads

 Left Arm-Right Arm
 Dextrocardia
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 How to Estimate HR:
 1) 30 Large Boxes = 6 seconds
 HR = # QRS or P wave x 10

4x10
40/min

16x10
160/min
 How to Estimate HR:
 2) RR Interval (# Big Boxes)
 HR = 300 150 100 75 60 50 43 37 33 30
#1 #2 #3 #4 #5 #6 #7 #8 #9 #10

#7
43/min

#2
150/min
 Normal
 60-100/min
 Bradycardia
 <60/min
 Tachycardia
 >100/min
 Seattle Criteria: Abnormal ECG findings in
Athletes
ECG findingbradycardia <30/min
 Profound Definition
Profound sinus > 3 seconds < 30 BPM
 Sinus pauses
bradycardia Sinus pauses ≥ 3 sec
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Normal
 Sinus
 Sinus
 Sinus Arrhythmia
 Sick Sinus Node
 Atrial
 Atrial Fibrillation
 Atrial Flutter
 Multifocal Atrial Tachycardia
 Paroxysmal Atrial tachycardia
 AV Node
 Junctional
 AV Block
 Supraventricular
 Supraventricular Tachycardia
 Ventricular
 VF/VT
 Pacemaker
 E CG Findings:
 3rd degree AV Block
 Complete AV dissociation
 Lyme
 Cardiac involvement in early disseminated stage
 Average 21 days from EM
 Conduction system disease:
 AV node block
 1st, 2nd, 3rd AV block
 Unresponsive to Atropine
 Usually benign and self-limiting
 May require temporary pacemaker
 Atrial Fibrillation

 Atrial Flutter

 Junctional

 SVT
 First Degree AV Block

 Second Degree AV Block Type 1

 Second Degree AV Block Type 2

 Third Degree AV Block

 Ventricular Fibrillation

 Ventricular Tachycardia

 Torsade de Pointes
 Normal Variant findings in Asymptomatic
Athletes
ECG
 Finding
Sinus arrhythmia
Sinus
 arrhythmia
Ectopic atrial rhythm
Ectopic

atrialescape
Junctional rhythmrhythm
Junctional escape rhythm
 1° AV block (PR interval > 200 ms)
1° AV block (PR interval > 200 ms)
 Mobitz Type I (Wenckebach) 2° AV block
Mobitz Type I (Wenckebach) 2° AV block
 Abnormal ECG findings in Athletes
 2° AV
ECG block Mobitz
finding type II
Definition
 3°
2° AVAV block
block Intermittently non-conducted P
Mobitz
 Atrialtype II waves SVT, AF, Atrial Flutter
tachyarrhythmias:
 PVCs ≥ 2 PVCsNo perPR10 prolongation
second tracingand PR
shortening
 Ventricular arrhythmias: Couplets, triplets, and non-
3° sustained
AV block ventricular
Complete heart block
tachycardia
Atrial SVT, AF, Atrial Flutter
tachyarrhythmias
PVCs ≥ 2 PVCs per 10 second tracing
Ventricular Couplets, triplets, and non-
arrhythmias sustained ventricular tachycardia
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Normal (-30 - +100)
 Lead I R+
 Lead AVF R+
 LAD (>-30)  RAD (>+100)
 Lead I R+  Lead I neg (rS)
 Lead AVF neg (rS, QS)  Lead AVF R+
 Abnormal ECG findings in Athletes
LADfinding
ECG -30° to
-90° Definition
RAD > 120° with RVH pattern
LAD (R-V1 + S-V5 > 10.5
-30° to -90°
mmwith
RAD ) RVH pattern > 120°
R-V1 + S-V5 > 10.5 mm
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Atrial Contraction
 Normal
 <2-3 mm amplitude
 <0.11 second width
 Gently rounded
 Upright in I, II, AVF, V4-6
 Inverted in AVR
 Diphasic or inverted in III
 Variable in AVL, V1-2
 Atrial enlargement/dilatation
 Increased Amplitude (>2-3mm)
 Increased Width (>0.12 second)
 Ectopic atria or AV junctional
 Inversion
 Absence
 AV junctional
 SA block
 P-mitrale/LAE
 Diphasic
 2nd half negative V1 (>1mm)
 Wide (>0.04s)
 Notched
 Wide, notched I, II (>0.12s)
 Tall I>III
 Seattle Criteria:
LAE
Abnormal ECG finding
LAE
 P-pulmonale/RAE
 Peaking
 Pointed II, III, AVF
 Tall III>I
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Beginning P wave to beginning QRS
 Atria through AV junction
 Normal
 0.12-0.20 second
 Prolonged
 Normal variant
 AV block
 Hyperthyroidism
 Lyme disease
 Shortened
 Normal variant
 AV junctional
 WPW
 LGL syndrome
 Fabry, collagen storage
 Pheochromocytoma
 Hypertension
 ECG Findings:
 Short PR< 0.12 seconds
 Delta wave
 WPW
 General
 0.2% Population
 Accessory AV pathway (Kent bundle)
 Tachyarrhythmia
 Clinical features
 Asymptomatic
 Palpitations
 ECG Features
 PR< 0.12 seconds
 QRS> 0.10 seconds
 Delta wave
 WPW
 General
 0.2% Population
 Accessory AV pathway (Kent bundle)
 Tachyarrhythmia
 Clinical features
 Asymptomatic
 Palpitations
 ECG Features
 PR< 0.12 seconds
 QRS> 0.10 seconds
 Delta wave
 Abnormal ECG findings in Athletes
ECG finding pre-excitation
 Ventricular Definition
Ventricular pre-excitation
 PR interval < 0.12 s PR interval < 0.120 s
 Delta wave Delta wave
 Wide QRS (> 0.12 s) Wide QRS (> 0.120 s)
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 End P wave to beginning QRS
 Normal
 Isoelectric
 Displaced
 Atrial infarction
 Acute pericarditis
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Ventricular depolarization
 Normal
 Duration
 Limb: 0.05 - 0.10 s
 Chest: 0.06 - 0.12 s
 Amplitude
 Limb: >5 mm
 Chest: >10 mm
 <20-30mm
 Q wave
 Normal but Small (<0.03 second)
 V5-V6, II, III, AVF
 Wide
 Bundle Branch Block
 Drugs
 Low Voltage
 Normal variant
 Obesity
 Emphysema
 Pericardial effusion
 Pleural effusion
 Hypothyroidism (myxedema)
 High Voltage (LVH)
 Hypertension
 Hypertrophic cardiomyopathy
 SV1 + RV5 or RV6
 >35mm >30yo
 >40mm 20-30yo
 >60mm 16-20yo
OR
 Precordial R + S >45mm
OR
 R Lead I >14mm
OR
 R aVL >12mm
 R V1 + S V5 >10.5 mm
 RAD
 ECG Findings:
 LVH
 ST segment elevation
 T wave inversion
 2-5/1000
 Gene mutations
 MYH7 or MYBPC3 genes
 Clinical presentation
 Dyspnea
 Chest pain
 Syncope
 Sudden death
 ECG
 LVH 80-90%
 ST segment elevation
 T wave inversion
 Q waves septal
 Arrhythmias e.g. AF
 ECG Findings
 Sinus Tachycardia
 120/min
 S1 Q3 T3
 RBBB
 Pulmonary Embolism
 ECG Features
 Sinus Tachycardia, AF
 S1 Q3 T3
 RAD
 RAE (P-pulmonale)
 RBBB
 Q wave Location Leads
 Anteroseptal V1-V3
 Anterior V2-V4
 Anterolateral V4-V6
 High lateral I, aVL
 Inferior II, III, aVF
 LBBB
 RBBB
 Others
 ECG
 V1 rSR, wide R
 V6 qRS, wide S
 I Wide S
 Complete: >0.12 s
 Causes
 Normal variant
 Pulmonary embolism
 COPD with pulmonary hypertension
 RVH
 ECG
 V1 Wide QS or rS
 V6 Wide, tall R
No Q
 I Wide R
No Q
 Complete: >0.12 s
 Causes
 Hypertensive heart disease
 Valvular lesions
 Cardiomyopathy
 LVH
 Abnormal ECG findings in Athletes
LVH
ECG finding Definition
 Not isolated
Pathologic LVH
Q waves > 3 mm in depth or > 40 ms in duration
 With LAE, LAD, ST segment depression,
(2 or more leads) T wave inversion, or
pathologic Q waves Except III and aVR
RVH pattern
Complete LBBB QRS ≥ 120 ms
 R-V1 + S-V5 > 10.5 mm and RAD > 120°
QS or rS in lead V1
 Pathologic Q waves
Upright monophasic R wave in leads I
 > 3 mm in depth or > 40 ms in duration (2 or more leads)
and V6
 Except III and aVR
Intra-ventricular Any QRS duration ≥ 140 ms
 Complete LBBB
conduction delay
 QRS ≥ 120 ms
LVH with other LVH criteria with LAE, LAD, ST
 QS or rS in lead V1
abnormalities
 Upright monophasic Rsegment
wave in depression, T wave inversion,
leads I and V6
or pathologic Q waves
 Intra-ventricular conduction delay
RVH pattern
 Any R-V1
QRS duration ≥ 140 ms + S-V5 > 10.5 mm
RAD > 120°
 Normal Variant findings in Asymptomatic
Athletes
ECG finding
Isolated QRS voltage criteria for LVH
Incomplete
IncompleteRBBB
RBBB
Isolated QRS voltage criteria for LVH
Except: with LAE, LAD, ST segment depression, T
wave inversion, or pathologic Q waves
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 J pt (QRS takeoff) to beginning T wave
 Beginning ventricular repolarization
 Normal
 Isoelectric with TP segment
 <1mm elevation limb
 <2mm elevation chest
 <0.5mm depression
 Depression
 >0.5mm depression
 Causes
 Myocardial ischemia
 Hypokalemia
 Elevation
 >1mm elevation limb
 >2mm elevation chest
 Causes
 Myocardial ischemia
 Acute pericarditis
 Hyperkalemia
 Brugada
 Early repolarization
 Early repolarization
 2-5% Population
 Normal variant, young, male
 J point elevated
 ST elevation in upward
concave pattern
 Tall peaked T wave
 Precordial leads V3-V4. Also
other leads lateral, inferior
and anterior.
 No reciprocal depression
 Early repolarization
 2-5% Population
 Normal variant, young, male
 J point elevated
 ST elevation in upward
concave pattern
 Tall peaked T wave
 Precordial leads V3-V4. Also
other leads lateral, inferior
and anterior.
 No reciprocal depression
 ECG Findings:
 Right precordial (V1-3)
 ST elevation
 T wave inversion
 Brugada Syndrome
 5/10,000
 Autosomal dominant
 Na channel mutations
 Clinical presentation
 Male predominance
 Endemic in Southeast Asia
 Sudden unexpected nocturnal death syndrome
 Brugada Syndrome
 Right precordial ST
elevation (V1-3)
+
 One or more
 Documented VT/VF
 Unexplained syncope
 Nocturnal agonal
breathing
 Inducible VF
 Family history of sudden
cardiac death <45yo or
coved ECG
 ECG Findings:
 ST elevations
 PR depression
 Acute Pericarditis
 Clinical presentation
 Chest pain, fever palpitations
 Pericardial rub, tachycardia
 ECG Stages
 I. ST elevation (all leads except aVr)
and PR depression
 II. J point returns to baseline
 III. T wave inversion
 IV. ECG resolution
 Other ECG Features
 Sinus tachycardia
 Low voltage QRS (effusion)
 Electrical alternans
 AMI Pericarditis

ST Convex Concave
Elevation

PR - +
depression
T wave Before ST After ST
inversion normalization normalization
Q wave + -
 ECG Findings
 Sinus Tachycardia
 Low Voltage
 PR segment depression
 Electrical Alternans
 Alternation of QRS complexes
 Usually in a 1:1 ratio
 Abnormal ECG findings in Athletes
ECG finding
ST segment Definition
depression
ST segment ≥ 0.5(2mm
≥ 0.5 mm in depth in depth
or more leads)(2 or more leads)
depression
Brugada-like ECG pattern
Brugada-like
 Leads V1-V3 Leads V1-V3
ECG pattern
 High High
take-off and take-off and
downsloping STdownsloping ST
segment elevation
 Negative T wave segment elevation
Negative T wave
 Normal Variant findings in Asymptomatic
Athletes
 Early
ECG repolarization
finding
 STrepolarization
Early elevation, J point
(STelevation, J waves,
elevation, J pointorelevation,
terminal QRS
J
slurring
waves, or terminal QRS slurring)
 Convex
Convex (“domed”)
(“domed”) STST segment
segment elevation
elevation combined
combined
with
with T wave
T wave inversion
inversion in in leads
leads V1-V4
V1-V4 in in
Afro/Caribbean athletes
Afro/Caribbean athletes
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Ventricular repolarization
 Normal
 Upright I, II, V3-V6
 Inverted AVR
 Variable III, AVL, AVF, V1-2
 <5mm limb
 <10mm chest
 Sharply pointed symmetrical
 MI
 Tall
 HyperK
 MI, ischemia
 CNS disorder
 Flattened
 Obesity, HypoK (+U wave)
 Inverted
 MI, ischemia
 CNS disorder
 ECG Findings:
 Tall, Peaked T waves
 Hyperkalemia
 K 5.5-7.5
 LAFB, LPFB
 Tall, peaked T wave
 K 7.5-10
 1st degree AV block
 Flat/wide P wave
 K >10
 Wide IVCD
 VT, VF
 ECG Findings:
 Epsilon wave
 T-wave inversion V1-V3
 Arrhythmogenic Right Ventricular Dysplasia
 General
 Northern Italy, France, Germany, Japan
 Clinical presentation
 Palpitations during exertion
 PVCs
 Syncope
 Sudden cardiac death as first manifestation rare
 RV arrhythmias, failure
 Major Criteria
 RV structural abnormalities
 RV abnormal tissue with fatty infiltration
 T wave inversion in V1-V3
 QRSd >100msec in V1-V3
 Epsilon wave
 Family history of ARVD
 Abnormal ECG findings in Athletes
ECG finding
T wave inversion Definition
T wave
 > 1 mminversion
in depth > 1 mm in depth
 V2-V6 (2 or more leads) • V2-V6 (2 or more leads)
 II and aVF • II and aVF
 I and aVL • I and aVL
 Excludes III, aVR, and V1 Excludes III, aVR, and V1
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Beginning QRS to end T wave
 Total ventricular re/depolarization
 QTc
 QT/(square root RR)
 Normal
 QTc <0.44 sec Male
 QTc <0.46 sec Female
 Prolonged
 Idiopathic
 Genetic Mutations
 LQTS
 Drug
 Macrolides, Quinidine, Procainamide, Disopyramid, Sotalol, Amiodarone
 Electrolytes
 HypoKalemia, Hypocalcemia
 Hypothermia
 MI, ischemia
 Subarachnoid hemorrhage
 Shortened
 Genetic Mutations
 Electrolytes
 Hyperkalemia, Hypercalcemia
 ECG Findings:
 Prolonged QT
 QT = 0.6 sec
 RR = 1 sec

 QTc = 0.6 sec

 General
 1/3,000-5,000
 Gene Mutation
 LQTS 1, 2, 3, others
 Clinical Presentation
 Asymptomatic
 Syncope
 Palpitation
 Sudden cardiac death
 Family history of sudden cardiac death
 Torsade de Pointes
 Prolonged repolarization (QT interval)
 Polymorphic VT with twisting of QRS axis
 Usually self-limiting but could degenerate into
VF and sudden death
 Metabolic Abnormalities
 Hypocalcemia
 Hypokalemic Metabolic Alkalosis
 Hypocalcemia
 Prolonged QT interval
 Prolonged ST segment
 Narrow QRS
 Short PR interval
 Hypokalemia
 Prolonged QT interval
 ST depression
 Flat T wave
 Prominent U wave
 Abnormal ECG findings in Athletes
ECG
 Longfinding
QT interval Definition
Long QT≥interval
 QTc QTc ≥ 470 ms (male)
470 ms (male)
QTc ≥ 480 ms (female)
 QTc ≥ 480 ms (female)
QTc ≥QT
 QTc ≥ 500 ms (marked 500 ms (marked QT
prolongation)
 Short QT interval prolongation)
Short
 QTcQT≤interval
320 ms QTc ≤ 320 ms
I. Rate
II. Rhythm
III. Axis
IV. P wave
V. PR interval
VI. PR segment
VII. QRS complex
VIII. ST segment
IX. T wave
X. QT duration
XI. U wave
 Final phase ventricular repolarization
 Normal
 Small, rounded
 Prominent
 Hypokalemia
 Drugs
 Quinidine, phenothiazine
 CVA
 Negative
 MI, LVH
 ECG Findings
 Prolonged QT interval
 Flat T wave
 Prominent U wave

 Hypokalemia
Thank You

Donald F. Kreuz, MD, FACC

Columbia University