Understanding EKG;s

what color is the RA

white

What color is the LA

black

What color is the LL

red

what color is the RL

green

what electrode is the ground lead

green or LL

difference between two electrodes is known as what

a Lead

lead 1

Electrode 1 (RA) to Electrode 2 (LA)

lead 2

electrode 1 to electrode 3

lead 2

electrode 2 to electrode 3

what do bipolar leads do

measure voltage difference between two electrodes

Augmented limb leads measure what?

The positive pole is a real electrode, but the negative pole is a calculated reference made by the ECG machine from the other limb electrodes. (compares each electrode to the average of the other two electrodes a

aVR

Right arm compared to the average of left arm and left leg

aVL

Right arm compared to the average of left arm and left leg

aVF

Left leg (foot) compared to the average of right arm and left arm

Vector

represents the overall direction and strength of electrical activity moving through the heart.

Segment

flat or mostley flat on isoelectric lin

Tp Wave

-atrial Repolarization

-hidden in QRS

Q wave

first negative deflection of QRS

R Wave

first positive of QRS

S Wave

first negative after R

intrinsicoid Deflection

-measured from the begginning of the QRS to the point where the R wave starts to become negative (how fast the electrical impulse is reaching the outer wall (epicardium) of the ventricle under a specific lead)

-can detect enlarged or thick ventricles

-ST Segment

-period after ventricullar depolarization and before ventricular repolariation

-should be neutral with baseline

T-Wave

-ventricular repolarization

-should be slighlty asymetrical

symmetrical T waves can be an early sign of what?

A STEMI

Peaked T-Waves

hyperkalemia

normal QT interval

less then 40% of the R-R Inerval

QTc Interval

-QT interval corrected for heart rate

-standardized Qt without fast or slow heart rythms

QT +1.75 x (Vent Rate - 60)

placement of electrode 4

mid-clavicular line

All augmented leads are __________

positive

CT stands for?

Centrail Termain, Representing th heart in Augmented Lead directions

aVR

CT to electrode 1

aVL

CT to electrode 2

aVF

CT to electrode 3

Normal Axis

• Positive in Lead I and aVF

Left axis deviation

lead 1 = positive

aVF = negative

Right axis Deviation

lead 1 = negative

aVF = positive

Extreme Rright Axis

lead 1 = negative

aVF = negative

transitional zone

lead where R=S

Rotation Zone

Whether that transition occurs earlier or later then expected

Left Atrial enlargment

P-mitrale

Inter-atrial conduction delay

P-mitrale

-wide, cammel humps

-associated with mitral valve disease

inter-atrial Conduction Delay (Left Atrial Enlargment)

notched P in v1 (two peaks)

or

biphasic P in v1 (P-Wave has both a postive and negative component, first wave is bigger)

Right Atrial Enlargment

P-Pulmonale

Inter-Atrial conduction

Inter Atrial conduction delay (Right Atrial Enlargment)

Biphasic P in v1

Second phase is bigger

Where does a Biphsic P appear in Atrial Enlargment

appears in V1

P-Pulmonale

-tall peaked p waves

-associated with bicuspid valve disease

Wandering Atrial Pacemaker

pacemaker sit takes place in difference places

What does PR segment Deppresion represent

-variant

-pericarditis

-atrial Infarction

Short PR Interval

-normal variant in children

-Junctional P wave

-Lown Ganong-Levine Syndrom

-Wolff-Parkinson-White Syndrom

long PR Interval

-Normal in elderly and sinus brady

-AV block

Wolff-Parkinson-White Syndrom

condition in which a person is born with an extra electrical pathway between the atria and ventricles.

-Kent Bundle

-Delta Wave

-shortend pr interval

Changes in QRS amplitude

Low voltage QRS (could be cardiac tamponade)

Left Ventricular Hypertrophy - enlarged Left ventricle

Right Ventricular Hypertrophy - enlrged right ventricle

Low Voltage QRS

amplitude < 5mm in all limb leads

amplitude <10mm in all precordial leads

Left Ventricular Hypertrophy Criteria

• depth of S in V1 + Height of R in v6 ≥ 35mm

• Any precordial lead (V1-V6) ≥ 45mm

• aVL ≥ 11mm

• Lead 1 ≥ 12mm

• aVF ≥ 20mm

Phyiological occourance in Left Ventricular Hypertrophy

enlarged left ventricle, which causes a large QRS Complex

RIght Ventricular Hypertrophy

enlarged Rigtht Ventricle

Criteria for a Right Ventricular Hypertrophy

height of R wave > depth of S wave in v1 ro v2

EKG findings with COPD

-right axis deviation

-sagging PR and St segments

-low voltage QRS in left precordial leads

-clockwise rotation

-RAE and RVH - core pulmonole

-multifocal atrial tachy

Q waves are significant if

≥0.03 seconds

≥ 1/3 of the height of the R wave

Q wave is naturally deeper on

expiration

Q wave is naturally smaller on

inspiration

benign Q waves are also calle what

septal or normal Q waves

Significant Q waves

-deep, wide

-sign of previous myocardial infarction

Changes in QRS width

-Left Bundle Branch Blocks

-Right Bundle Branch block

-Intraventricular Conduction Delay

-Fascicular Blocks

-Bifascicular blocks

-Accelerated indiovnetricular

implanted pacemaker

Left Bundle Branch block

-block in conduction to the left ventricle

-wide QRS

-broad R wave in Lead 1, v6

Broad S in V1

Right Bundle Branch Block

-problem with cunduction to right Ventricle (results in wide QRS)

-slurred S wave in leads 1 and V6

-Rabbit ears (RSR) in V1

Intraventricular Conduction Delay(IVCD)

-slow impulse through venticles

-result in wide QRS

-broad category for bundle branch blocks

Fasicular block

block where left bundle branch splits (left anterior or left posterior fasicular block)

Left aterior fasicular block

-left axis deviation

Left posterior Fascicular Block

right axis deviation

The normal QRS axis is approximately:

−30∘ to +90

Bifascicular block

2/3 of the main ventricular conduction pathways are blocked

-right bundle branch

-left anterior fasicle

-left posterior fasicle

paced rythms look similar to _________

Left bundle branch blocks

paced rythms start in what ventricle

Right Ventricle

when does ventricular repolarization take place

T wave

J- point

-point on the ECG where the QRS complex ends and the ST segment begins.(junction between the QRS and ST segment)

-Represents when ventricles are full depolarized

Concave ST segment can be _______ or ___________

concave up, concave down

ST segments Cocave up

early repolarization (pericarditis)

ST segment Concave down

-curve like a frown

-increased suspicion of myocardial infarction

Normal St segment is characterized by

-sitting at baselone (isoelectric line)

-no elevation or deppression

ST Elevation

• ST segment is above baseline.

• Can be seen with:

  • STEMI

  • Pericarditis

  • Early repolarization

ST deppression

• ST segment is below baseline.

• Often suggests ischemia.

• Can also be seen with LVH strain.

pericarditis in a 12 lead

-ST elevation that is often seen in every or most leads

Strain Pattern

suggests a ventricle—most commonly the left ventricle—is under chronic pressure overload and is repolarizing abnormally.

It's most often seen with:

• Left Ventricular Hypertrophy (LVH)

• Severe hypertension

• Aortic stenosis

you'll see:

1. ST-segment depression

2. T-wave inversion (T Wave is upside down)

Flat, Deppressed ST segment

Subendocardial Ischemia - BF isn’t getting to the inner layer of the heart muscle

Flat ST elevation

common sign of STEMI/ acute myocardial injury

Tombstone ST Segment

-QRS, ST segment, and T wave almost merge together.

-commonly associated with:

• Large STEMI

• Persistent ST elevation from ventricular aneurysm

Ventricular Aneurysm

weakened, bulging area of the ventricular wall, usually the left ventricle, that develops after a large myocardial infarction (heart attack).

T Wave characteristic

-should be less then 2/3 the height of its associated R or S wave

In a biphasic T wave, the first part should be positive

The leads with the largest QRS voltage (usually V5/V6)

will show the most dramatic strain pattern

strain pattern is classically associated with

hypertophy

RVH with Strain Pattern (Must have more then one of the following criteria)

P-Pulmonale (RAE)

right axis deviation

increase R;S ratio in V1 and V2 (R wave is taller)

Q1S2T3 pattern

Dyspnea + clear lung sounds +RVH with strain = Pulonary Embolism

difference between a strain and an infarction

-both have elevated ST segments

-both can have inversed T waves

-infarction has pathologic Q waves (abnormally large)

benign Early Repolarization (BER)

-ST elevation (not a Stemi)

-notch at J point

-upward concave of St segment

-common in african Americans

Pericarditis in an ECG

-PR deppresion

-diffuse ST elevation

-concave ST

-notching at the end of QRS

Concordant

-T wave is same direction as associated R and S

-presence of a block usually indicated ischemia

Discordant

T wave is opposite of associted R and S

QT Interval characteristics

<1/2 RR Interval for normal heart beats

Bazetts’s formula

-used for QT interval correction when heart beat isnt normal

prolonged QT segmant increases risk for ___________

torsadoes De Pointes, which can generate into V-FIB