Allied Health - Chapter 5: Cardiac Electrical System

Pathway of Electrical Signal

An electrical impulse from the SA node at the top of the right atrium fires and is transmitted to the AV node, which prolongs the ventricles from contracting, so all blood from the atrium is pumped out. The signal is then sent to the Bundle of His, then the bundle branches, and then into the purkinje fibers. This then causes the ventricles to contract.

Normal BMP Range

60 - 100 BMP

QRS Complex

When the ventricles contract

P Wave

Contractions of both artiums

Sinus

regular/ normal rhythm

What do the impulse make the heart do?

The electrical stimulus travels down through the conduction pathways and causes the heart's ventricles to contract and pump out blood

SA node functions

• natural pacemaker

• The electrical stimulus travels down through the conduction pathways and causes the heart's ventricles to contract and pump out blood

AV node functions

• gatekeeper

• delaying the signal to allow for proper ventricular filling

Asystole

Rhythm that has no electrical activity, use CPR

Ventricular Tachycardia

The QRS Complex is irregular, and increased R complexes

Ventricular Tachycardia

Use AED, chest pain, shortness of breath, shockable rhythm)

Ventricular fibrillation

quiver, blood is stagnant, cardiac arrest, unconious, shockable rhythm

Atrial flutter

saw-toothed” flutter

Atrial fibrillation

quivering, blood is stagnant, which can cause clots, then stroke, signal is coming from everywhere) usage of blood thinners

Sinus tachycardia

regular

3rd degree heart block or complete heart block

1st degree heart block Wenckebach

longer, longer, longer, longer, drop,

1st degreed heartblock

SVT (supraventricular tachycardia)

Sinus bradycardia

regular

Sinus rhythm

regular regular

Temporal

A

Carotid

B

Apical

C

Brachial

D

Radial

E (thumb)

Ulnar

E (pinky)

Femoral

F

Popliteal

G

Posterial tibial

H

Dorsalis pedis

I

Electrical signal Heart Diagram

AV node blocked

heart rate is slowed leading to heart block, implanted pacemaker is needed

Damage to bundle branches

rhythm will slow to a block, distance between the p-wave and QRS complex

Extra electrical impulses

blood is pumeped ineffecientely due to an increases/ irregular heart rate (a-fib, SVT, a-flutter)