Heart ECG

Electrocardiograms

​Cardiac Cycle

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​Cardiac Cycle

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Multiple Choice

What is the contraction phase of a heartbeat?

• Cardiac

• Impulse

• Systole

• Diastole

 How long does the average cardiac cycle last?

Multiple Choice

 How long does the average cardiac cycle last?

• .08 seconds

• 0.8 seconds

• 8 seconds

• 8 minutes

Intrinsic (ANS)

• PNS and SNS​

Extrinsic

• ​Endocrine and Baroreceptors- stretch/pressure in the carotid artery

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Regulation of the Heart

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Sympathetic

Increases rate and forces contractions

Parasympathetic (branches of Vagus n.) Slows the heart rate

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Autonomic Regulation

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Multiple Choice

Heart rate can increase due to stimulation by this division of the autonomic nervous system?

• SNS

• PNS

• SAS

• NSS

​Pacemaker

​The SA node or sinus node is able to spontaneously generate and propagate electrical impulses

generating the heart rate​

60-100 b​pm

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Sinoatrial node​

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Multiple Choice

What is the pacemaker of the heart?

• SA node

• AV node

• Brain

• Spinal cord

• ​SA node

  • atrium contraction​

• ​AV node

• bundle of HIS

• right and left branching purkinje fibers

  • ventricle contraction​

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​Electrical innervation of the Heart

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Multiple Choice

What part of the hearts conduction system is shown in the diagram?

• SA node

• AV Node

• AV bundle

• Purkinje Fibers

Multiple Choice

What part of the hearts conduction system is shown in the diagram?

• SA node

• AV Node

• AV bundle

• Purkinje Fibers

Measures the electrical impulses ​of the heart

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Depolarization is the contraction phase (systole)

​Repolarization is the relaxation phase (diastole)

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P= atrial systole

QRS= ventricle systole

​T= ventricle diastole

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Electrocardiogram

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Multiple Choice

What is the name of the circled area of the ECG in the diagram?

• P Wave

• QRS Complex

• T Wave

• Cardiac Cycle

​Which of these terms refers to when the electrical impulse starts in the SA node and causes the atria to contract?

Multiple Choice

Which of these terms refers to when the electrical impulse starts in the SA node and causes the atria to contract?

• Repolarization 

• Atrial depolarization 

• Ventricular depolarization 

• ECG cycle

Electrocardiogram

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​Abnormal timing or contraction of the heart

• Bradycardia

  • ​resting heart rates that fall below 60 bmp

• Tachycardia

  • resting heart rate that is above 100 bpm

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​​Arrhythmia

Multiple Choice

Bradyarrhythmia is defined as:

• any rhythm disorder with a heart rate less than 40 beats per minute

• any rhythm disorder with a heart rate less than 60 beats per minute

• any symptomatic rhythm disorder with a heart rate less than 50 beats per minute

• any rhythm disorder with a heart rate less than 50 beats per minute

​Abnormal timing or contraction of the heart

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• ​Ventricular tachycardia (vtach)

  • ventricles, rather than SA node, cause beat ​

​​Arrhythmia

Multiple Choice

A life threatening arrhythmia in which the ventricles, rather than the SA node initiate the beat. The heart rate is between 150 and 250 bmp, requiring immediate medical intervention

• bradycardia

• premature atrial contraction (PAC)

• ventricular tachycardia

• atrial fibrillation

​Abnormal timing or contraction of the heart

• ​Atrial fibrillization (afib)

  • atria contract faster than 350 bpm

• Ventricular fibrillation (vfib)

  • ventricles contract faster than 350 bpm

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​​Arrhythmia

Multiple Choice

A condition in which the atrial tissue is very irritated, causing the atria to beat at a rate greater than 350bpm. The atria don’t beat in a coordinated manner, they simply quiver. On the ECG it is represented as a wavy line and the rhythm is irregular.

• premature atrial contraction (PAC)

• arrhythmia

• premature ventricular contraction (PVC)

• atrial fibrillation

​Abnormal timing or contraction of the heart

• ​Heart Block

  • impulse from SA node to AV node

    • first–impulse delayed

    • second–intermittently blocked

    • third–completely blocked

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​​Arrhythmia

Multiple Choice

Choose the 3rd degree heart block:

Artificial Pacemakers

devices used to regulate the contraction of atriums or ventricles​

AED (automated external difibulator)

emergency ​device used to send an electrical impulse to help reestablish heart rhythm

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Medical Devices​

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Multiple Choice

Why is defibrillation important? 

• It prevents rearrest from occurring
• It is not important for cardiac arrest
• There is a 100% success rate in regaining a normal cardiac rhythm
• It can restore a regular cardiac rythm

Multiple Choice

It happens when the heart muscles weaken....

• heart attack

• cardiac arrest

• heart failure

Multiple Choice

It happens due to electrical problems in the heart...

• heart failure

• heart attack

• cardiac arrest

Multiple Choice

You can save a person's life who has cardiac arrest by giving ______.

• medicine

• CPR

• oxygen

Multiple Choice

True or False: Cardiac arrest and heart attack are the same thing

• True

• False

What a heart attack looks like

A Heart Attack occurs when the blood flow that brings oxygen to the heart muscle has been slowed or stopped.

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Heart attack continued

This happens because coronary arteries that supply the heart with blood can slowly become thicker and harder from a buildup of fat, cholesterol and other substances, called plaque. It's similar to the stuff that grows on your teeth!

Heart attack continued

If the plaque breaks open and a blood clot forms that blocks the blood flow, a heart attack occurs. See image and next slide will show more.

Heart attack continued

The blood supply is less and tissues in the heart start to die, this is bad.

Heart Attack continued

That dead tissue is where the heart attack happens. Notice the heart how the color has changed. This is a sign the heart tissue is dying and there could be greater problems.

What is cardiac arrest?

cardiac arrest is caused when the heart’s electrical system malfunctions.

Is a heart attack the same as cardiac arrest?

No. Remember, a heart attack is caused by a blockage that stops blood flow to the heart. Cardiac arrest is an electrical problem in the heart.

Emergency Treatment of Cardiac Arrest

Here are the signs:

Sudden loss of responsiveness The person doesn’t respond, even if you tap him or her hard on the shoulders, or ask loudly if he or she is OK. The person doesn’t move, speak, blink or otherwise react. No normal breathing The person isn’t breathing or is only gasping for air.

What to do

Yell for help and tell someone nearby to call 911 or your emergency response number. Ask that person or another bystander to bring you an AED (Automated External Defibrillator) and start CPR!

Check breathing

If the person isn’t breathing or is only gasping for air, administer CPR. Look, listen and feel for 10 seconds while checking for breathing. Look at their chest to see it it's rising, listen to their nose for air movement, and feel on your cheek for moisture from the breath.

Multiple Select

When checking breathing, what are the three things we look for?

• Chest Rise

• Toes are wiggling

• Listen for air in your ear

• Feel warmth of breath on cheek

• Eyes blinking

Give CPR: Push hard and fast

Remember to do chest compressions 30 times and 2 breaths. Compressions should be at a depth of 1 1/2 to 2 inches.

Multiple Choice

What is the rate of compressions and breaths for CPR?

• 13/2

• 30/2

• 20/3

• 15/2

Multiple Choice

Depolarization means

• contracting

• relaxing

Multiple Choice

Choose the correct sequence of impulse spread in normal conducting pathways:

• SA node --> AV nodes --> Internodal pathway --> Bundle of HIS --> Bundle branches --> Purkinje fibers

• SA node --> AV nodes --> Internodal pathway --> Bundle of HIS --> Purkinje fibers --> Bundle branches

• SA node --> Internodal pathway --> AV nodes--> Bundle of HIS --> Bundle branches --> Purkinje fibers

The three major ions that involve in generation of action potential of SA node are sodium, calcium and potassium.

Multiple Choice

Choose the correct event that occur during pacemaker potential.

• Influx of sodium ions

• Influx of calcium ions

• Efflux of potassium ions

Multiple Choice

The most important event that responsible for depolarization in action potential of SA node cells is

• Influx of sodium ions

• Influx of calcium ions

• Efflux of potassium ions

There are three important events that before and during the action potential generation.

This slide is to show the relationship of electrical impulse conduction with the activity of the heart.

Multiple Choice

Choose one correct statement of electrical activity with cardiac event.

• SA node depolarization occurs concurrent with atrial contraction

• SA node depolarization leads to spread of impulses within the atrial

• SA node depolarization occurs concurrent with AV node depolarization

note refractory period for cardiac muscle fibers lasts as most as long as muscle contraction, in comparison to skeletal muscle fibers.

Parasympathetic stimulation decreases the heart rate. However sympathetic stimulation increases heart rate and force of contraction.

Multiple Select

The effect(s) of sympathetic stimulation to the heart is(are)

• increases the rate of depolarization of SA node

• increases excitability of cardiac cells

• increases AV nodal delay

• increases contractility of atrial muscle

Multiple Select

The effect(s) of parasympathetic stimulation to the heart is(are)

• decreases the rate of depolarization of SA node

• decreases excitability of cardiac cells

• decreases AV nodal delay

• decreases contractility of ventricular muscle