The document provides information on basics of EKG, including: 1) Anatomy and physiology of the cardiac conduction cycle, how the electrical movement is represented graphically, and anatomy of normal sinus rhythm. 2) Common arrhythmias like premature ventricular complexes, junctional rhythms, and types of heart block. 3) The EKG procedure and patient preparation. 4) Typical cardiac medications and labs used to diagnose cardiac conditions.

1. BASICS OF EKG

2. Anatomy and Physiology
• Cardiac Conduction Cycle
Graphic Representation of Cardiac Cycle
• How does the Electrical movement manifest on graph paper
• Cardiac Cycle “Family”
• Anatomy of a Normal Sinus Rhythm
Arrythmias
• Know that there are many different types of arrythmias
• The different locations arrythmias stem from
• Typical arrhythmias seen
EKG Procedure
• Patient Preperation
• Lead Placement
Typical Cardiac Medication
Cardiac Labs

3. Anatomy and Physiology of Cardiac
Cycle

4. Anatomy of the Conduction Cycle
What Parts of the Heart
Make Up The Conduction
System
SA Node
AV nodes
Bundle of HIS
Right Bundle Branch
Left Bundle Branch
Purkinje Fibers

5. The PQRST of Normal Sinus
Rhythm

6. The Conduction Cycle
Press arrow
to play
video

7. P WAVE-
PR INTERVAL
 P WAVE represents atrial
depolarization(electrical
stimulation) and when it
occurs on the EKG or strip
we know that the atrial
cells have received the
stimulus from the SA
Node.
 PR INTERVAL: The PR
interval measures the
time it takes the impulse
to travel from the atria to
the ventricles.

8. PR SEGMENT
• In between the P wave and
the beginning of the QRS
complex you will notice a
flat line. That is when the
impulse enters the AV Node,
where it is held until the
ventricles are ready to
receive it. This is a normal
delay in the travel of the
impulse through the heart.
Because its in aholding
pattern, there is no electrical
stimulation which causes
the line to return to the flat
isoelectric line.

9. QRS COMPLEX
• QRS complex
represents
ventricular
depolarization and
when it occurs we
know the ventricular
cells have received
the stimulus.
• It is measuring the
time it takes the
impulse to travel
through the
ventricles.

10. ST SEGMENT
T WAVE
• ST SEGMENT: an isolectric
line following the QRS
complex. It is telling us
that the ventricles are
repolarizing.
• T WAVE: last wave form
during a NSR. When this
occurs we know that the
ventricles have recovered
and are ready for the next
impulse to occur.

11. The Cardiac Cycle Family
(2 full QRST complexes on the graph)
All of these waveforms
When the cardiac can be positive (above
The cardiac cycle cycle is normal all the isoelectric line),
family includes of the waveforms negative (below the
the P wave, QRS (PQRST) will be isoelectric time) or
and ST segments present on the biphasic (waveforms
and the T Wave rhythm strip of with components
EKG above and below the
isoelectric line)

12. RECOGNIZING NORMAL SINUS
RHYTHM ON AN EKG STRIP.

13. • The EKG paper is divided into small squares and large squares. Ea ch large square contais 25
small quares.
• On the horizontal line, one small square represents .04 seconds and one large square
represents .20 seconds in time
• On the vertical line one small square represents 1 mm and one large square reoresebts 5mm
in voltage.
• 30 large squares equals 6 seconds in time. When calculating time for the different waves,
segments and complexes you count the amount of small squares and multiply by o.4
• When calculating the heart rate., you are also counting the ventricular rate: count the
number of squares inbetween the two spikes of the QRS complex..
• 30 large squares equal 6 second strips. You can calculate the HR by counting how many QRS
complexes there are in a six second time frame and multiplying by ten.

14. Normal Sinus Rhytm Requirements
 Ventricular Rate: 60-100bpm
 Ventricular Rhythm: Regular
 Ventricular rhythm is determined by measuring the R-R
interval. The R-R interval is the dcistance between 2 QRS
complexes
 PWAVES: P waves should be present, a P wave for ever QRS
and the configuration normal for eh lead. P waves should
be upright in Lead II and the can be upright, biphasic or
inverted in Lead V1 (rhythm strips on telemetry floors and
the bottom of the 12 lead ekg, are lead II)
 Atrial Rate : 60- 100
Count how many boxes inbetween the p waves. Or , on a second
strip count how many p waves and multiply by 10.

15. Normal Sinus Rhytm Requirements
 Atrial Rhythm is determined by measuring the P-P interval .
They should be the same distance between on each
measured. A variation of 0.12 seconds (3 small squares)
can occur and the rhythm is considered regular.
 PR Interval: The PR interval measures the time it takes the
impulse to travel from the atria to the ventricles.
 QRS: The QRS duration measures the time it takes the
impulse to travel through the ventricles.
 Twaves should all have the same configuration. Twaves
have a wealth of information in them and is important to
study, they are almost the most unstable component of an
EKG. A different T wave configuration does not always
mean something is going on.

16. NSR BY THE NUMBERS

17. Abnormalities That Can Be Diagnosed
with EKG
• : Hyperkalemia,
Shortened QT interval • some drugs,
• certain genetic abnormalities
• Hypokalemia
Prolonged QT interval: • some drugs
• certain gentic abnormalities
Coronary Ischemia,
• :
•hypokalemia,
Flattened or Inverted T waves •Left Ventricular hypertropy
•, Digoxin effect, s
•some drugs.
• 1st sign of acute MI, where T waves become more prominent, symmetrical
Hyperacute T Waves: and pointed
PVCs present: • Low Magnesium
Peaked Twaves, widened • Hyperkalemia
QRS complex, Depressed ST
Flattened T waves, Prominent • Hypokalemia
U waves

19. • Sinus Bradycardia
• A heart rate less than 60 beats per minute (BPM). This
in a healthy athletic person may be 'normal', but other
causes may be due to increased vagal tone from drug
abuse, hypoglycaemia and brain injury with increase
intracranial pressure (ICP) as examples
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - less than 60 beats per minute
QRS Duration - Normal P Wave - Visible before each
QRS complex P-R Interval - Normal Usually benign and
often caused by patients on beta blockers

20. • SINUS TACHYCARDIA
• An excessive heart rate above 100 beats per minute (BPM)
which originates from the SA node. Causes include stress,
fright, illness and exercise. Not usually a surprise if it is
triggered in response to regulatory changes e.g. shock. But
if their is no apparent trigger then medications may be
required to suppress the rhythm
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - More than 100 beats per minute
QRS Duration - Normal P Wave - Visible before each QRS
complex P-R Interval - Normal The impulse generating the
heart beats are normal, but they are occurring at a faster
pace than normal. Seen during exerc

21. • Supraventricular Tachycardia (SVT) Abnormal
• A narrow complex tachycardia or atrial tachycardia which originates in the
'atria' but is not under direct control from the SA node. SVT can occur in all
age groups
• Looking at the ECG you'll see that:
• Rhythm - Regular
• Rate - 140-220 beats per minute
• QRS Duration - Usually normal
• P Wave - Often buried in preceding T wave
• P-R Interval - Depends on site of supraventricular pacemaker
• Impulses stimulating the heart are not being generated by the sinus node,
but instead are coming from a collection of tissue around and involving
the atrioventricular (AV) node

22. • Atrial Fibrillation
Many sites within the atria are generating their own electrical impulses, leading to irregular conduction
of impulses to the ventricles that generate the heartbeat. This irregular rhythm can be felt when
palpating a pulse
• Looking at the ECG you'll see that:
• Rhythm - Irregularly irregular Rate - usually 100-160 beats per minute but slower if on medication
QRS Duration - Usually normal P Wave - Not distinguishable as the atria are firing off all over P-R
Interval - Not measurable The atria fire electrical impulses in an irregular fashion causing irregular
heart rhythm Fibrillation
• Many sites within the atria are generating their own electrical impulses, leading to irregular
conduction of impulses to the ventricles that generate the heartbeat. This irregular rhythm can be
felt when palpating a pulse
• Looking at the ECG you'll see that:
• Rhythm - Irregularly irregular Rate - usually 100-160 beats per minute but slower if on medication
QRS Duration - Usually normal P Wave - Not distinguishable as the atria are firing off all over P-R
Interval - Not measurable The atria fire electrical impulses in an irregular fashion causing irregular
heart rhythm

23. • Atrial Flutter
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Around 110 beats per
minute QRS Duration - Usually normal P Wave -
Replaced with multiple F (flutter) waves, usually
at a ratio of 2:1 (2F - 1QRS) but sometimes 3:1 P
Wave rate - 300 beats per minute P-R Interval -
Not measurable As with SVT the abnormal tissue
generating the rapid heart rate is also in the atria,
however, the atrioventricular node is not involved
in this case.

24. • 1st Degree AV Block
• 1st Degree AV block is caused by a conduction delay
through the AV node but all electrical signals reach the
ventricles. This rarely causes any problems by itself and
often trained athletes can be seen to have it. The
normal P-R interval is between 0.12s to 0.20s in length,
or 3-5 small squares on the ECG.
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Normal QRS Duration - Normal
P Wave - Ratio 1:1 P Wave rate - Normal P-R Interval -
Prolonged (>5 small squares)

25. • 2nd Degree Block Type 1 (Wenckebach)
• Another condition whereby a conduction block of
some, but not all atrial beats getting through to the
ventricles. There is progressive lengthening of the PR
interval and then failure of conduction of an atrial beat,
this is seen by a dropped QRS complex.
• Looking at the ECG you'll see that:
• Rhythm - Regularly irregular Rate - Normal or Slow QRS
Duration - Normal P Wave - Ratio 1:1 for 2,3 or 4 cycles
then 1:0. P Wave rate - Normal but faster than QRS rate
P-R Interval - Progressive lengthening of P-R interval
until a QRS complex is dropped

26. • 2nd Degree Block Type 2
• When electrical excitation sometimes fails to pass through
the A-V node or bundle of His, this intermittent occurance
is said to be called second degree heart block. Electrical
conduction usually has a constant P-R interval, in the case
of type 2 block atrial contractions are not regularly
followed by ventricular contraction
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Normal or Slow QRS Duration -
Prolonged P Wave - Ratio 2:1, 3:1 P Wave rate - Normal but
faster than QRS rate P-R Interval - Normal or prolonged but
constant

27. • 3rd Degree Block
• 3rd degree block or complete heart block occurs when
atrial contractions are 'normal' but no electrical conduction
is conveyed to the ventricles. The ventricles then generate
their own signal through an 'escape mechanism' from a
focus somewhere within the ventricle. The ventricular
escape beats are usually 'slow'
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Slow QRS Duration - Prolonged P
Wave - Unrelated P Wave rate - Normal but faster than QRS
rate P-R Interval - Variation Complete AV block. No atrial
impulses pass through the atrioventricular node and the
ventricles generate their own rhythm

28. • Bundle Branch Block
• Abnormal conduction through the bundle branches will
cause a depolarization delay through the ventricular
muscle, this delay shows as a widening of the QRS complex.
Right Bundle Branch Block (RBBB) indicates problems in the
right side of the heart. Whereas Left Bundle Branch Block
(LBBB) is an indication of heart disease. If LBBB is present
then further interpretation of the ECG cannot be carried
out.
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Normal QRS Duration - Prolonged P
Wave - Ratio 1:1 P Wave rate - Normal and same as QRS
rate P-R Interval - Normal

29. • Premature Ventricular Complexes
• Due to a part of the heart depolarizing earlier than it
should
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - Normal QRS Duration - Normal P
Wave - Ratio 1:1 P Wave rate - Normal and same as QRS
rate P-R Interval - Normal Also you'll see 2 odd
waveforms, these are the ventricles depolarising
prematurely in response to a signal within the
ventricles.(Above - unifocal PVC's as they look alike if
they differed in appearance they would be called
multifocal PVC's, as below)

30. • Junctional Rhythms
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - 40-60 Beats per
minute QRS Duration - Normal P Wave - Ratio
1:1 if visible. Inverted in lead II P Wave rate -
Same as QRS rate P-R Interval - Variable Below
- Accelerated Junctional Rhythm

31. • Ventricular Tachycardia (VT) Abnormal
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - 180-190 Beats per
minute QRS Duration - Prolonged P Wave - Not
seen Results from abnormal tissues in the
ventricles generating a rapid and irregular heart
rhythm. Poor cardiac output is usually associated
with this rhythm thus causing the pt to go into
cardiac arrest. Shock this rhythm if the patient is
unconscious and without a pulse

32. • Ventricular Fibrillation (VF) Abnormal
• Disorganised electrical signals cause the ventricles to
quiver instead of contract in a rhythmic fashion. A
patient will be unconscious as blood is not pumped to
the brain. Immediate treatment by defibrillation is
indicated. This condition may occur during or after a
myocardial infarct.
• Looking at the ECG you'll see that:
• Rhythm - Irregular Rate - 300+, disorganised QRS
Duration - Not recognisable P Wave - Not seen This
patient needs to be defibrillated!! QUICKLY

33. • Asystole - Abnormal
• Looking at the ECG you'll see that:
• Rhythm - Flat Rate - 0 Beats per minute QRS
Duration - None P Wave - None
• Carry out CPR!!

34. • Myocardial Infarct (MI)
• Looking at the ECG you'll see that:
• Rhythm - Regular Rate - 80 Beats per minute
QRS Duration - Normal P Wave - Normal S-T
Element does not go isoelectric which
indicates infarction

35. LABORATORY TESTS
CMP
Look for electrolyte imbalances.
Particularly look for K+
Pre –cath look at renal functioning due to dye.
Magnesium level
CBC
Complete blood count,
Focus on hemoglobin and hematocrit
BNP
High levels are an indicator for congestive heart failure
PT/INR
especially if patient is on anticoagulation therapy

36. SCREENING CARDIAC PANEL
• TROPONIN
– High specificity for myocardial cell injurty, cardiac troponin and
cardiac troponin1 helpful in evaluation of patients with chest
pain
– More specific for cardiac injury than CPK-MB
– Elevation sooner and remain elevated longer than CPK-MB
– Allows longer time for Dx and thrombolytic tx of MI.
– Used for differentiating cardiac from non cardiac chest pain
– Evaluation of patients with unstable angina
– Estimate the size of the MI
– Detect preop MI

37. SCREENING CARDIAC PANEL
• CPK-MB ( creatine phosphokinase)
– Specific for myocardial cells
– Levels rise three to six hours after damage
– If damage is not persistent the levels peak at 18
hours post damage
– Returns to normal after two to three days
Cardiac panels are usually done in serial draws.
Usually q 8hrs, or q4/12/24hrs. After admit.

38. DIAGNOSTIC TESTS
• EKG
• ECHOCARDIOGRAM
• STRESS ECHO
• TILT TABLE TEST
• CARDIAC CATHERIZATION
• ELECTROPHYSIOLOGY TEST
• CT HEART SCAN
• MYOCARDIAL BIOPSY
• HEART MRI
• PERICARDIOCENTESIS

39. ECG/EKG PROCEDURE
• ECG Basics
• The electrocardiogram (ECG) is a diagnostic tool that measures and records the electrical activity of
the heart in detail. Being able to interpretate these details allows diagnosis of a wide range of heart
problems.
• ECG Electrodes
• Skin Preparation:
• Clean with an alcohol wipe if necessary. If the patients are very hairy – shave the electrode areas.
• ECG standard leads
• There are three of these leads, I, II and III.
Lead I: is between the right arm and left arm electrodes, the left arm being positive.
Lead II: is between the right arm and left leg electrodes, the left leg being positive.
Lead III: is between the left arm and left leg electrodes, the left leg again being positive.
• Chest Electrode Placement
V1: Fourth intercostal space to the right of the sternum.
V2: Fourth intercostal space to the Left of the sternum.
V3: Directly between leads V2 and V4.
V4: Fifth intercostal space at midclavicular line.
V5: Level with V4 at left anterior axillary line.
V6: Level with V5 at left midaxillary line. (Directly under the midpoint of the armpit)

40. LEAD PLACEMENT ILLUSTRATIONS

41. A little More Info about EKG
Chest Leads View
V1 & V2 Right Ventricle
V3 & V4 Septum/Lateral Left Ventricle
V5 & V6 Anterior/Lateral Left Ventricle
ECG Leads The ECG records the electrical activity that results when the heart muscle cells in the atria and ventricles contract.
Atrial contractions show up as the P wave.
Ventricular contractions show as a series known as the QRS complex.
The third and last common wave in an ECG is the T wave. This is the electrical activity produced
when the ventricles are recharging for the next contraction (repolarizing).
Interestingly, the letters P, Q, R, S, and T are not abbreviations for any actual words but were
chosen many years ago for their position in the middle of the alphabet.
The electrical activity results in P, QRS, and T waves that are of different sizes and shapes. When
viewed from different leads, these waves can show a wide range of abnormalities of both the
electrical conduction system and the muscle tissue of the hearts 4 pumping chambers.
- Views of the Heart

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