By M.elkhatib CIN

SA node- 60-100bpm

AV node- 40-60bpm

Bundle branches- 20-40bpm

Regular - RR interval constant

Basically regular – premature atrial/ventricular ectopic

Regularly irregular - RR interval variable but

with a pattern

Irregularly irregular - RR interval variable with

no pattern

Sinus Rhythm

Sinus Brady

Sinus Tachy

Atrial Tachy

Atrial Flutter

Junctional Tachy

AVNRT/AVRT

VT

1 & 3 degree HB

Sinus arrhythmia

Atrial fibrillation

Wenkebach

Mobitz 2

VF

Horizontally

One small box - 0.04 s

One large box - 0.20 s

Vertically

One large box - 0.5 mV

Small boxes

Number of small boxes between RR or PP

1500 divide by number of small boxes

Example 15 small boxes between the peaks

of two RR - 1500/15 = HR 100bpm.

Number of large boxes between 2 RR/PP

intervals

Divide 300 by the number of large boxes

Example

5 large boxes between 2 RR complexes

300/5 =60bpm

Quick and dirty method great for an irregular

rhythm

Measure 6 second strip and x by ten.

Sinus Brady

Sino atrial arrest

Wenkebach

Mobitz type 2

CHB

Sinus Tachy

Atrial Tachy

A flutter

Atrial fibrillation

VT

VF

Junctional Tachy

Nodal re-entrant Tachy

Re-entrant Tachy

Does a P wave precede every QRS

Is it positive or negative in the correct leads

Do all the p waves look alike

What is the shape of the p wave

What is the ratio of p waves to QRS complexes

Normal p waves upright (except AVR) round with 1:1ratio

P Mitrale

A wide bifurcated P - wave

Left atrial enlargement

P Pulmonale

Tall P wave

Right atrial hyptrophy

AV junctional rhythm

Atrial fibrillation

Atrial flutter

Sino-atrial block

Dextrocardia

Incorrectly placed limb leads

Ectopic beats

Beginning of P wave to the beginning of QRS

Normal = 0.12 -0.20 secs

No more than 5 small squares

PR interval > 0.20 sec

secondary to drugs (digoxin/beta blockers)

Hypokaleamia

Congenital abnormalities (ASD, TGA)

First degree AV Block

<0.12 secs

Wolf Parkinson White syndrome (ventricular

muscle stimulated early)

Junctional rhythm

Dissociated beats (CHB)

Wenkebach

Wandering pacemaker

Premature atrial beats

AV dissociation

The length of time taken to depolarise the ventricles

<0.12 secs (3 small squares)

Q - first negative deflection

R- first positive deflection

S negative deflection after R

Any upward deflection after the R above the isoelectricline is classed as another R

QRS - 0.12 secs or greater

Common cause BBB

Abberant conduction

Think VT, VF, CHB

Dead or stunned myocardial tissue

Usually permanent

Can be reversed with early intervention

More than 1mm in depth

0.02 secs or greater in V1-V2

0.04 secs or more and greater than one-third of the R wave (although their is much dispute over this)

Reflects length of time from the beginning of

ventricular depolarisation to the end of repolarisation

QT interval corrected for heart rate variability

The ECG machine corrects this

The corrected figure is called the QTc

Should be no more than 440ms

Slight variation in peadiatrics depending on age

Inherited

Medicine induced- amioderone, sotolol

Hypocalceamia, hypokaleamia,hypomagnesia

Induce torsades de points.

Digoxin therapy

Hypercalacaemia

Represents recovery or repolarisation of the

ventricles

Measured from the end of the QRS to the

beginning of the T wave

The ST is normally isoelectric

ST elevation-MI (STEMI)

ST Depression (NSTEMI)

Pericarditis

Angina

Hyperkalemia

Digoxin therapy

Tachycardia

Hypokaleamia

BBB

Ectopics

Cardiomyopathies

• Reflects repolarisation or ventricular muscular relaxation ,T wave changes seen in:

MI

Ischemia

electrolyte imbalances

medications

pericarditis

Cardiomyopathies

Upright round wave seen in lead II after Twave and before the next P wave

Not clearly understood

Associated with hypokaleamia, amioderone

& digoxin

The general flow of electrical activity of the heart

It relates to the flow of depolarisation wave through the heart

This can change with position of the heart

Generally related to changes in electricalflow

Left ventricular hypertrophy

LBBB - bifasicular block

LBBB + 1st degree HB - trifasicular block

Mechanical shift of the heart

Normal variant

Right Ventricular Hypertrophy

RBBB

Dextrocardia

Mechanical shift

Normal variation