CARDIAC/ECG MODULE

THE HEART

CORONARY ARTERIES

FIBRILLATING HEART

CORONARY ARTERIES HEART

PRACTICE RHYTHMS

PRACTICE RHYTHMS

ELECTRICAL CONDUCTION

• SA Node (60 – 100)• Primary pacemaker

• AV Node (40 – 60)• ***Creates a pause***

• Secondary pacemaker if

SA fails to fire

• Bundle of His

• L & R Bundle Branches

• Perkinje Fibers (20 – 40)• Final pacemaker if

SA and AV fail to fireBundle of His

AV Junction

ELECTRICAL CONDUCTION

Bundle of His

AV Junction

ANIMATION OF HEARTBEAT / PQRST

TERM - DEPOLARIZATION

Cells Depolarize• Produce electrical

energy

• Cause muscle to

contract

Batteries Discharge• Deliver electrical

energy

• Cause electric motor to spin, music to play

TERM - REPOLARIZATION

Cells RepolarizeBatteries Recharge

ELECTRICAL COMPLEX

• P wave = atria depolarize

• QRS = ventricles depolarize

• T = ventricles repolarize

Each PQRST complex normally causes one heartbeat.

SHAPE OF COMPLEXES

• What do sinus complexes look like?• Presence of a round “upright” P wave

• Rate usually between 60 - 100

• What do junctional complexes look like?• Missing a round “upright” P wave

• Rate usually between 40 - 60

• What do ventricular complexes look like?• Wide bizarre looking QRS

• Rate usually between 20 - 40

SHAPE OF QRS COMPLEX

• Height Depends on

your view point!• Worry about width

not the height!

GOOD BAD

GOOD GOOD

ECG GRAPH PAPER

Remember:

* Paper speed is 25 mm/sec

* 1 little box width is .04 seconds (.04 x 5 = .2 seconds)

* 1 big box width is .2 seconds

* ECG calibration 1mV tall (2 big boxes)

ECG Machine

Calibration

1 mV tall (2 boxes)

FINDING THE RATE

• Count the number of QRS complexes in a 6 second

strip and multiply by 10.

FINDING THE RATE

• Rule of 300- Divide 300 by the number of boxes

between each QRS = rate (REGULAR RATES ONLY!)

Number of big boxes

Rate

1 300

2 150

3 100

4 75

5 60

6 50

RATES

• Sinus < 60 is called: sinus bradycardia

• Sinus 60 – 100 is called: normal sinus rhythm

• Sinus > 100 is called: sinus tachycardia

• Junctional 40 – 60 is called: junctional rhythm

• Junctional 60 – 100 is called: accelerated junctional rhythm

• Junctional >100 is called: junctional tachycardia

• Ventricular 20 – 40 is called: ventricular rhythm (idioventricular IVR)

• Ventricular 40 – 100 is called: accelerated ventricular rhythm

• Ventricular > 100 is called: ventricular tachycardia (V-tach)

PRACTICE RHYTHMS

SINUS TACYCARDIA

PRACTICE RHYTHMS

NORMAL SINUS RHYTHM

PRACTICE RHYTHMS

NORMAL SINUS RHYTHM

Don’t worry about the direction of the QRS.

PRACTICE RHYTHMS

SINUS BRADYCARDIA

PRACTICE RHYTHMS

Note: Not a 6 second strip

JUNCTIONAL TACHYCARDIA

Note: Not a 6 second strip

PRACTICE RHYTHMS

ACCELERATED JUNCTIONAL RHYTHM

PRACTICE RHYTHMS

SUPRAVENTRICULAR TACHYCARDIA

A giant term that simply means it is NOT coming from the

ventricles! Might be junctional or might be atrial.

PRACTICE RHYTHMS

IDIOVENTRICULAR RHYTHM (IVR)

PRACTICE RHYTHMS

ACCELERATED VENTRICULAR RHYTHM

PRACTICE RHYTHMS

VENTRICULAR TACHYCARDIA

Always shortened to “V Tach”

Example: Patient is in V tach.

PRACTICE RHYTHMS

V TACH INTO V FIB

An AED would advise a shock for either of these rhythms!

PRACTICE RHYTHMS

V FIB / A FIB

Atrial Fibrillation: fibrillation instead of P waves & irregular rhythm

PRACTICE RHYTHMS

VERY COOL STRIP!!!

Sinus to V Tach – SHOCK - ------------V Fib --------------------SHOCK ---- sinus

PRACTICE RHYTHMS

NORMAL SINUS RHYTHM WITH PVC

PRACTICE RHYTHMS

1ST DEGREE HEART BLOCK

PR interval greater than .20 (1 big box) is a 1st degree heart

block. The delay at the AV node is too long.

.28

2ND DEGREE HEART BLOCK

Some of the impulse can’t pass through the AV node and

the QRS’s get dropped.

COMPLETE HEART BLOCK – 3RD DEGREE

None of the atrial impulses get though the AV node. The sinus node

fires at its own rate of 60-100 (see the P waves) and the ventricles fire

at their own rate of 20 – 40. Only the ventricles produce a pulse! This is

very dangerous and will require a pacemaker to be inserted ASAP.

PACED RHYTHMS

Heart with a pacemaker set at 60 is in place. See the pacer

spikes?

Failure to capture. The pacemaker doesn’t always cause a contraction.

The patient may feel lightheaded or even faint.

4 LEAD VS 12 LEAD

4 LEAD ECG

• Looks for rhythm problems

• Has 4 limb wires (W, B, R & G)

• Great for continuous

monitoring

12 LEAD ECG

• Looks for heart attacks also

• Has 4 limb wires (W, B, R & G)

• Has 6 chest wires (V1 – V6)

• 10 wires (6+4) can give us 12 leads or “views” of the heart.

4 LIMB LEAD PLACEMENT(BIPOLAR)

6 CHEST OR PRECORDIAL LEAD PLACEMENT (UNIPOLAR)

V1 4th Intercostal space (ICS) – right sternal border

V2 4th Intercostal space (ICS) – right sternal border

V4 5th ICS – Mid clavicular line (MCL)

V3 Between V2 and V4

V6 5th ICS – Mid Axillary Line

V5 Between V4 and V6

60 Hz AC - Electrical interference

ECG cables near electric machinery

such as hospital bed motor etc. or

poor grounding of equipment.

TECHNICAL PROBLEMS

Artifact can be cause by:

• Somatic Tremor – shivering,

patient moving, nervousness

• Touching cables

• Poorly attached electrode(s)

• ECG cable movement while

recording the strip can cause

a wandering baseline

OBTAINING A QUALITY 12 LEAD

1. Skin prep is important• Dry wet or oily skin

• Shave or clip chest hair

• Gently abrade dead skin

2. Reduce chance for artifact• Minimize patient movement

• Secure cables – no big loops

• Watch electrical interference

LEADS ARE VIEWS OF THE HEART

Like cars, no one lead (view) shows it all.

WHAT A 12 LEAD ECG LOOKS LIKE

12 Leads: I AVR V1 V4

II AVL V2 V5

III AVF V3 V6

Called Bipolar because leads “look” between 2 poles

Remember:

- Regular Limb leads (I, II, III ) are Bipolar

- Augmented leads are Unipolar

- Chest (Precordial )Leads are Unipolar

aVR – Right Side aVL – Left Side aVF - Foot

Remember:

- Regular Limb leads (I, II, III ) are Bipolar

- Augmented leads are Unipolar

- Chest (Precordial )Leads are Unipolar

ST ELEVATION = MI (STEMI)ST ELEVATED MYOCARDIAL INFARCTION

Locating the ST elevation helps to find the heart attack!

HEART ATTACK LOCATION CHART

MI Location Leads showing Leads showing

ST elevation ST depressions

WHERE IS THE HEART ATTACK?

Rate: ______________________

Rhythm: ____________________

Impression: _________________

_____________________________

WHERE IS THE HEART ATTACK?

Rate: ______________________

Rhythm: ____________________

Impression: _________________

_____________________________

SCENARIO #1 CHEST PAIN (PART 1)

45 year old male complaining of chest pain for 2 hours. You

attach him to the monitor and this is the ECG strip recorded in

Lead II.

Rate: ________ Rhythm: __________________________

Do you see anything on the strip to be concerned with? Yes No

If Yes, explain: ____________________________________________________

SCENARIO #1 CHEST PAIN (PART 2)

Rate: ______________________

Rhythm: ____________________

Impression: _________________

_____________________________

SCENARIO # 2 ROUTINE PHYSICAL

Rate: ______________________

Rhythm: ____________________

Impression: _________________

_____________________________

SCENARIO # 3 ROUTINE PHYSICAL

You record this 12 Lead at a clinic and the M.D. tells you to repeat it.

Why? ____________________________________________________________

Give possible causes: _____________________________________________

Give possible solutions: ___________________________________________