Download ECGs MADE EASY

BASIC
ELECTROCARDIOGRAPHY
Dr. Riko Prima Putra, SpJP
ELECTROCARDIOGRAM

The electrocardiogram (ECG) is a graphic
recording of the electrical potentials produced by
the cardiac tissue.


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Electrical impulse formation occurs within the
conduction system of the heart.
Excitation of the muscle fibers throughout the
myocardium results in cardiac contraction.
The ECG is recorded by applying electrodes to
various locations on the body surface and
connecting them to a recording apparatus.
Sinus Rhythms
Normal Sinus Rhythm
Rate
Rhythm
P waves
PR interval
QRS
60-100 beats per minute
Atrial regular
Ventricular regular
Uniform in appearance, upright, normal shape, one
preceding each QRS complex
0.12-0.20 second
0.10 second or less. If greater than 0.10 second in
duration, the QRS is termed “wide” since the
existence of a bundle branch block or other
intraventricular conduction defect cannot be
accurately detected in a single-lead.
Sinus Rhythms
Sinus Bradycardia
Rate
Rhythm
P waves
PR interval
QRS
Less than 60 beats per minute
Atrial regular
Ventricular regular
Uniform in appearance, upright, normal
shape, one preceding each QRS
complex
0.12-0.20 second
Usually 0.10 second or less
Sinus Rhythms
Sinus Tachycardia
Rate
Rhythm
P waves
PR interval
QRS
Usually 100-160 beats per minute
Atrial regular
Ventricular regular
Uniform in appearance, upright, normal
shape, one preceding each QRS
complex
0.12-0.20 second
Usually 0.10 second or less
Sinus Rhythms
Sinus Dysrhythmia (Arrhythmia)
Rate
Rhythm
P waves
PR interval
QRS
Usually 100-160 beats per minute but may
be faster or slower
Irregular (R-R intervals shorten during
inspiration and lengthen during
expiration)
Uniform in appearance, upright, normal
shape, one preceding each QRS
complex
0.12-0.20 second
Usually 0.10 second or less
Atrial Rhythms
Premature Atrial Complexes
Early (premature) P waves
Upright P waves that differ in shape from normal
sinus P waves in Lead II
1.
2.
•
3.
P waves may be biphasic (partly positive, partly
negative), flattened, notched or pointed
The early P wave may or may not be followed by a
QRS complex
Atrial Rhythms
Premature Atrial Complexes (PACs)
Rate
Rhythm
P waves
PR interval
QRS
Usually normal but depends on underlying rhythm
Essentially regular with premature beats
Premature
Differ from sinus P waves – may be flattened, notched,
pointed, biphasic, or lost in the preceding T wave
Varies from 0.12-0.20 second when the pacemaker site
is near the SA node; 0.12 second when the
pacemaker site is nearer the AV junction
Usually less than 0.10 second but may be prolonged.
The QRS of the PAC is similar to those of the
underlying rhythm unless the PAC is abnormally
conducted.
Atrial Rhythms
Supraventricular Tachycardia
Rate
Rhythm
P waves
PR interval
QRS
150-250 beats per minute
Regular
Atrial P waves may be seen which differ from sinus P
waves (may be flattened, notched, pointed, or
biphasic). P waves are usually identifiable at the
lower end of the rate range but are seldom identifiable
at rates above 200. May be lost in the preceding T
wave.
Usually not measurable because the P wave is difficult
to distinguish from the preceding T wave. If P waves
are seen, the RR interval will usually measure 0.120.20 second.
Less than 0.10 second unless an intraventricular
conduction defect exists.
Atrial Rhythms
The Unstable Patient
Signs and Symptoms

Shock

Chest pain

Hypotension

Shortness of breath

Pulmonary congestion

Congestive heart failure

Acute myocardial infarction

Decreased level of consciousness
Atrial Rhythms
ELECTRICAL THERAPY – Synchronized Countershock
Description and Purpose
Synchronized countershock reduces the potential for delivery of energy
during the vulnerable period of the T wave (relative refractory period).
A synchronizing circuit allows the delivery of a countershock to be
“programmed”. The machine searches for the peak of the QRS
complex (R wave deflection) and delivers the shock a few
milliseconds after the highest part of the R wave.
Indications:

Supraventricular tachycardia

Atrial fibrillation

Atrial flutter
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Unstable ventricular tachycardia with pause
Atrial Rhythms
Atrial Flutter
Rate
Rhythm
P waves
PR interval
QRS
Atrial rate 250-350 beats per minute; ventricular rate
variable – determined by AV blockade. The ventricular
rate will usually not exceed 180 beats per minute due
to the intrinsic conduction rate of the AV junction.
Atrial regular
Ventricular may be regular or irregular
Not identifiable P waves; saw-toothed “flutter waves”
Not measurable
Usually less than 0.10 second but may be widened if
flutter waves are buried in the QRS complex or if an
intraventricular conduction defect exists.
Atrial Rhythms
Atrial Fribrillation
Rate
Atrial rate usually greater than 350-400 beats
per minute; ventricular rate variable
Rhythm
Ventricular rhythms usually very irregular; a
regular ventricular rhythm may occur
because of digitalis toxicity.
P waves
No identifiable P waves; fibrillatory waves
present. Erratic wavy baseline.
PR interval
Not measurable
QRS
Usually less than 0.10 second but may be
widened if an intraventricular conduction
defect exists.
Ventricular Rhythms
Premature Ventricular Complexes
Rate
Usually normal but depends on the underlying
rhythm
Rhythm
Essentially regular with premature beats. If the
PVC is an interpolated PVC, the rhythm will
be regular.
P waves
There is no P wave associated with the PVC
PR interval
None with the PVCs because the ectopic beat
originates in the ventricle
QRS
Greater than 0.12 second.
Wide and bizarre.
T wave frequently in opposite direction of the
QRS complex.
Ventricular Rhythms
Patterns of PVCs
1.
2.
3.
4.
5.
Pairs (couplets) – two sequential PVCs
Runs or bursts – three or more sequential PVCs are
called vntricular tachycardia (VT)
Bigeminal PVCs (ventricular bigeminy) – every other
beat is a PVC
Trigeminal PVCs (ventricular trigeminy) – every third
beat is a PVC
Quadrigeminal PVCs (ventricular quadrigeminy) –
every fourth beat is a PVC
Ventricular Rhythms
Common Causes of PVCs

Normal variant
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Anxiety
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Exercise
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Hypoxia
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Digitalis toxicity
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Acid-base imbalance
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Myocardial ischemia
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Electrolyte imbalance (hypokalemia, hypocalcemia, hypercalcemia,
hypomagnesemia)
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Congestive heart failure
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Increased sympathetic tone
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Acute myocardial infarction
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Stimulants (alcohol, caffeine, tobacco)
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Drugs (sympathomimetics, cyclic antidepressants, phenothiazines)
Ventricular Rhythms
Warning Dysrhythmias
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Six or more PVCs per minute
PVCs that occurred in pairs (couplets) or in
runs or three or more (ventricular tachycardia)
PVCs that fell on the T wave of the preceding
beat (R-on T phenomenon)
PVCs that differed in shape (multiformed
PVCs)
Ventricular Rhythms
Ventricular Tachycardia (VT)
Rate
Atrial rate not discernible, ventricular rate 100250 beats per minute
Rhythm
Atrial rhythm not discernible
Ventricular rhythm is essentially regular
P waves
May be present or absent; if present they have
no set relationship to the QRS complexes –
appearing between the QRS’s at a rate
different from that of the VT.
PR interval
None
QRS
Greater than 0.12 second.
Often difficult to differentiate between the QRS
and the T wave.
Ventricular Rhythms
VENTRICULAR TACHYCARDIA - CAUSES

Hypoxia

Exercise

R-on T PVCs

Catecholamines

Digitalis toxicity

Myocardial ischemia

Acid-base imbalance

Electrolyte imbalance

Ventricular aneurysm

Coronary artery disease
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Rheumatic heart disease
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Acute myocardial infarction
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CNS stimulants (cocaine, amphetamines)
Ventricular Rhythms
Ventricular Fibrillation
Rate
Rhythm
P waves
PR interval
QRS
Cannot be determined since there are no
discernible waves or complexes to
measure
Rapid and chaotic with no pattern or
regularity
Not discernible
Not discernible
Not discernible
Ventricular Rhythms
Defibrillation (Unsynchronized Countershock)
Description and Purpose:
The purpose of defibrillation is to produce momentary
asystole. The shock attempts to completely depolarize the
myocardium and provide an opportunity for the natural
pacemaker centers of the heart to resume normal activity.
Defibrillation is a random delivery of energy – there is no
relation of the discharge of energy to the cardiac cycle.
Indications:
 Unstable ventricular tachycardia with a pulse
 Pulseless ventricular tachycardia
 Ventricular fibrillation
 Sustained Torsades de Pointes
Ventricular Rhythms
Asystole
Rate
Rhythm
P waves
PR interval
QRS
Ventricular usually indiscernible but may
see some atrial activity.
Atrial may be discernible.
Ventricular indiscernible.
Usually not discernible
Not measurable
Absent
Ventricular Rhythms
Causes of Pulseless Electrical Activity (MATCHx4ED)
Myocardial infarction (massive acute)
Acidosis
Tension pneumothorax
Cardiac tamponade
Hypovolemia (most common cause)
Hypoxia
Hyperkalemia
Hypothermia
Embolus (massive pulmonary)
Drug overdoses (cyclic antidepressants, calcium channel
blockers, beta-blockers, digitalis)
“Bundle Branch” Blok Kanan (RBBB)
 Gangguan hantaran pada cabang kanan
Bundle His
 Dapat diakibatkan adanya fibrosis atau
kelainan bawaan
 Blok sempurna disebut RBBB komplit
 Blok tidak sempurna disebut RBBB
inkomplit dan dapat terjadi pada orang
normal
RBBB Komplit
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Di lead V1 atau V2
- QRS intv > 0,12” (broad notched R, rsr, rsR’ atau
rSR’
- Tipe QRS “M type” atau “ Shape” dimana R2 >
R1
Gelombang S dalam, negatif di V5-V6, QRS >
0,12”
Kadang ada kelainan repolarisasi
RBBB Inkomplit

Syaratnya sama dengan RBBB komplit tetapi QRS
intv antara > 0,08” - < 0,12”
RBBB Komplit
“Bundle Branch” Blok Kiri (LBBB)
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
Mempunyai arti klinis selalu patologis
Terbagi atas blok komplit dan inkomplit
LBBB Komplit:
QRS intv 0,12” atau lebih
2. QS atau RS di V1, gelombang R melebar dengan
ada lekuk di puncaknya (nothed)
3. Gelombang Q mengecil/hilang di lead I, aVL,
V5,V6
4. Kelainan repolarisasi berupa ST depressi
1.
LBBB inkomplit

Sama dengan LBBB komplit tetapi QRS intv
0,08”- 0,11”
LBBB Komplit
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