defibrillation course
DESCRIPTION
Defibrillation Course. Cross Section of the Heart. Flow of Blood Through The Heart. Heart Anatomy. LOCATION: retrosternal – behind the sternum SIZE AND SHAPE: Little bigger than the size of your fist Base – top of the heart Apex – Bottom of the heart. Organ Layers: - PowerPoint PPT PresentationTRANSCRIPT
Defibrillation Course
Cross Section of the Heart.Cross Section of the Heart.
Flow of Blood Through The Heart
Heart Anatomy
LOCATION: retrosternal – behind the
sternum
SIZE AND SHAPE: Little bigger than the size of your fist
Base – top of the heart
Apex – Bottom of the heart
Organ Layers:Inside layer – endocardium (smooth
muscle that lines the chamber)
Middle layer – myocardium (thickest muscle layer)
Outside Layer – epicardium
Pericardium – Protective sac surrounding the heart, 30cc of pericardial fluid acts
as a lubricant and cushion.
Heart Chambers
ATRIAL – superior chambers (if you are superior you are at the top)
- Right collects blood from the vena cavas.
- Left collects oxygenated blood from the lungs.
VENTRICLES – inferior chambers- Right pumps blood to lungs (LOW
pressure)- Left pumps blood out to body
(HIGH pressure)
SEPTUM – wall that separates the two sides of the heart
The 4 Chambers of the HeartThe 4 Chambers of the Heart
Right Atrium
Right Ventricle
Left Atrium
Left Ventricle
Receives blood from veins;Receives blood from veins;pumps to right ventricle.pumps to right ventricle.
Receives blood from lungs;Receives blood from lungs;pumps to left ventricle.pumps to left ventricle.
Pumps blood to the lungs.Pumps blood to the lungs. Pumps blood through the Pumps blood through the aorta to the bodyaorta to the body..
Heart ValvesFunction – to control blood flow through the heart.
Atrioventicular Valves(separate the atria & ventricles)
Tricuspid Valves (right side)
Mitral (Bicuspid) (left side)
Semilunar Valves
Pulmonic (right side)-between the right ventricle & pulmonary artery.
Aortic (left side)-between the left ventricle & the aorta.
Great VesselsLargest in the body to carry blood to and
from the heart.Vena Cava:
Superior – brings back blood from head and upper extremities
Inferior – brings back blood from area below the heart
Pulmonary Artery – carries deoxygenated blood to the lungs.
Pulmonary Vein – carries oxygenated blood back to the heart.
Aorta – carries oxygenated blood to the body.
Coronary Arteries2 main arteries
which sit on the surface of the heart; come off aortic arch.
IMPORTANCE – provides blood to the heart muscle itself (myocardium).
Flow of Blood Through The Heart
Oxygen LowConcentration
Vena CavaeRight Atrium(Tricuspid
Valve)Right Ventricle(Pulmonary
Valve)Pulmonary
Artery
L U N G S
Oxygen High ConcentrationPulmonary Vein
Left Atrium(Mitral Valve)Left Ventricle(Aortic Valve)Aorta
TO THE BODY
Blood Flow Through the Heart
It’s coloring time…
Pumping Action of the HeartStroke volume – the amount of blood ejected
from the ventricles with one contraction (60-100ml).
Cardiac Output – the amount of blood pumped through the circulatory system per minute.
FORMULA = heart rate x stroke volume
Normal Adult Heart Rate: 60-100 times per minute
What regulates the heart?
“Fight or Flight Response”
In response to the autonomic nervous system- Parasympathetic Nervous System
When activated, slows down the heart rate.
- Sympathetic Nervous System
Speeds up the heart rate.
Arteriosclerosis – hardening of the arteries
Atherosclerosis – fat and cholesterol deposits line the
vessels
Cardiac Assessment
What is the chief complaint?
1. Chest pain or discomfort – OPQRSTI
2. Previous episodes & history
3. Shoulder or neck pain
4. Dyspnea – worse with exertion?
5. Syncope
6. Palpitations
7. Past Medical History
Properties of the HeartAutomaticity
ability to beat on its own
Conductivityability to pass impulses from cell to cell
Contractibility
ability to receive an electrical impulse and contract
Excitabilityability to respond to an electrical stimulus
Rhythmiticitywhen stimulated, has rhythm
Depolarization:
When the heart contracts or pumps blood
Repolarization:
When the heart is resting and refilling
(RE=Rest)
What’s In a Heart Beat?
Electrocardiograph – Machine used to measure electrical heart activity.
Isoelectric Line – the black line on an ECG
Electrocardiogram – the read out or strip of paper showing the electrical activity.
ECG Placement - AED
Pacemakers of the Heart
• SA Node (sinoatrial) - Dominant pacemaker with an intrinsic rate of 60 - 100 beats/minute.
• AV Node (atrial ventricular) - Back-up pacemaker with an intrinsic rate of 40 - 60 beats/minute.
• Purkinje Fibers - Back-up pacemaker with an intrinsic rate of 20 - 40 bpm.
Cardiac Cardiac ConductionConductionSystemSystem
Cardiac Conduction & the ECG
SA node
AV node
Bundle of His
Bundle Branches
Purkinje fibers
What happens in a single heart beat??? - The “PQRST”
• P wave
– Atrial depolarization
– SA Node Fires
• T wave
-Ventricular Repolarization
• QRS - Ventricular depolarization- AV Node Fires
ATRIA RELAX BEFORE VENTRICLES CONTRACT
The PR Interval
Atrial depolarization
+
delay in AV junction
(AV node/Bundle of His)
(delay allows time for the atria to contract before the ventricles contract)
Types of AEDs
Biphasic
Sends shock in both directions, measures
resistance, and adjusts energy
Causes less damage to heart muscle
Monophasic
Sends single shock (energy current) from one pad to the other
Rationale for Early Defibrillation• Most frequent initial rhythm in sudden
cardiac arrest is ventricular fibrillation (VF)
• The only effective treatment for VF is defibrillation
• Probability of successful defibrillation decreases rapidly over time
Safety Considerations
Water
Dry patient’s chest; remove from wet environment.
Metal
Ensure no one is in contact with the patient and they are not touching any metal.
Additional SafetyConsiderations
Medication PatchIf patch is visible on the chest,
remove it with gloved hands before
delivering shock.
Safety Considerations
DO NOT defibrillate in a moving
ambulance – stop the vehicle to deliver the
shock. Road noise interferes in the
operation and it decreases the chance of
shocking another person
Use the proper pads: Adult pads for 8 and older and/or signs of puberty & Child Pads for 1 – 8 years old
Time is Critical• Immediately………….>95%
• 1 – 3 min……………..84%
• 4-6 min………………28 – 40%
• >10 min……………...<5%
Causes of Cardiac Arrest Other Than Heart Disease
• Drowning
• Trauma
• Electrocution
• Acid Base imbalance
• Electrolyte imbalance
• Drug toxicity
• Hypovolemia
• Hypoxia
Chain of Survival
Rhythms you NEED to know!!!
Ventricular Fibrillation - VF
Ventricular Tachycardia – VT
Asystole
Normal Sinus Rhythm
Pulseless Electrical Activity – PEA
Agonal – Dying Heart
Artifact
Premature Ventricular Contractions – PVC’s
Pacemaker
THE END
Not Shockable Rhythms
An AED will not shock:
Asystole (20-50% of victims) OR
Pulseless electrical activity (PEA) (15-20% of victims)
Typically only 6-7 out of 10 patients are in a shockable rhythm.
Safety Considerations
An AED must be applied ONLY to a patient who is unresponsive, apneic, and pulseless.
Say "Clear!" Ensure no one is touchingSay "Clear!" Ensure no one is touchingpatient. Press analyze button.patient. Press analyze button.
If AED advises shock, say "Clear," ensure If AED advises shock, say "Clear," ensure no one touching patient, and press shock no one touching patient, and press shock button. Repeat until up to 3 shocks are button. Repeat until up to 3 shocks are delivered.delivered.
Stacked Shocks
Key Term
Called stacked because after the first and second shocks in each set, pulse checks and CPR are not performed
After delivery of shock(s), check carotidAfter delivery of shock(s), check carotidpulse.pulse.
If there is no pulse, resume CPR for one If there is no pulse, resume CPR for one minute. Check effectiveness of CPR by minute. Check effectiveness of CPR by evaluating pulse.evaluating pulse.
Insert an airway adjunct and ventilate Insert an airway adjunct and ventilate with high-concentration oxygen.with high-concentration oxygen.
After one minute of CPR, clear patient After one minute of CPR, clear patient and repeat sequence of analyses and and repeat sequence of analyses and up to three additional shocks.up to three additional shocks.
If no shock is advised, check carotid If no shock is advised, check carotid pulse. If present, assess adequacy of pulse. If present, assess adequacy of breathing.breathing.
If breathing is adequate, give high-
concentration oxygen by nonrebreather.
If inadequate, ventilate with high-concentration oxygen.
If the AED gives 3 consecutive no-shock messages with no carotid pulse . . .
. . . or a total of six shocks are delivered . . . then transport with CPR and oxygen.
If advanced life support is not available, transport when:
Patient regains pulse, OR
You have delivered 6 shocks, OR
AED has given 3 consecutive no-shock messages
Do not touch patient when analyzing rhythm and delivering shocks.
Do not analyze rhythm or defibrillate in a moving ambulance. Stop first.
General AED Procedures
AED in Progress
If AED is in use by a first responder
when you arrive, ensure they are
performing properly, and continue
with shocks.
What happens in a single heart beat?
P wave - SA node fires - Depolarization of atria (contract)
QRS Complex - AV node fires- Depolarization of the ventricles. (contract)T Wave - Repolarization of the ventricles (rest and refill)
ATRIA RELAX BEFORE VENTRICLES CONTRACT