Download Electrocardiogram

Electrocardiogram
(ECG/EKG)
Allied Health II
• Primarily from blood turbulence caused by closing of the heart valves
• 4 heart sounds
• 1st 2 are loud enough to be heard
• Auscultation – listening to sounds within the body
Heart Sounds
• 1st sound
• Louder and longer than the 2nd sound
• Created by blood turbulence
• Associated with the closure of the AV valves soon after ventricular systole
begins
Lubb (S1)
• 2nd Sound
• Shorter and not as loud as the first
• Sound created by blood turbulence
• Associated with closure of the semilunar valves at the beginning of ventricular
diastole
Dupp (S2)
• Not normally loud enough to be heard
• S3 associated with rapid ventricular filling
• S4 associated with atrial contractions
Heart Sounds (S3 and S4)
• Lubb, dupp, pause, lubb, dupp, pause, lubb dupp, pause
• As heart rate increases, pause interval shortens
Cycle (at rest)
• SA Node – located in right atrium
• Natural pacemaker
• Begin each wave of muscle contraction in the heart
• Impulse in right atrium spreads over the muscles of both atria, causing them to
contract simultaneously
Electrical Activity
• Atrioventricular Node
• Impulses from SA node travel to AV node
• Located on floor of right atrium, near septum
• AV node transmits impulses on to the bundle of His.
Electrical Activity
• Bundle of His
• Located in the interventricular septum
• Branches of the bundle of His carry electrical impulses to right and left ventricles
and the Purkinje fibers
• Purkinje Fibers
• Stimulation of purkinje fibers causes ventricles to contract simutaneously, forcing
blood into aorta and pulmonary arteries
Electrical Activity
• Recording of the electrical changes that accompany each cardiac cycle
• Composite of action potentials produced by all the heart muscle fibers during
each heartbeat
• Electrocardiograph – instrument used to record the changes of an
electrocardiogram
Electrocardiogram (ECG or EKG)
Electrocardiogram
• First
• Small upward wave
• Represents atrial depolarization
• Spreads from SA node throughout both atria
• Atrial contraction
P Wave
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2nd wave
Begins as downward deflection
Continues as a large, upright, triangular wave
Ends as downward wave
Represents onset of ventricular depolarization
• Spread of wave through the ventricles
• Ventricular contraction
QRS Complex
• Signifies ventricular repolarization
• Relaxing & refilling of ventricles
T Wave
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10 Electrodes being placed
Place limb leads 1st
V1 – Right sternal border, 4th intercostal space
V2 – Left sternal border, 4th intercostal space
V4 – 5th intercostal space on left midclavicular line
V3 – evenly placed between V2 and V4
V6 – left mid-axillary
V5 – evenly spaced between V4 and V6
How to Apply the Leads
• https://www.pinterest.com/pin/63472675973700293/
How to Apply the Leads
• 6-second strip method
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Count number of QRS complexes in 6 seconds and multiply by 10
30 big blocks = 6 seconds
Less accurate
Go-to method for irregular rhythms
• Big block method
• Count the number of big blocks in between 2 QRS waves and divide into 300
• More accurate
• There are 300 big blocks in 1 minute
How to Calculate the HR
• A normal EKG (regular beats at 60-100bpm) is called = Normal Sinus
Rhythm (NSR)
• Sinus arrhythmia – rate increases with inhalation (common in children and
some adults)
• Ventricular Fibrillation – Vfib, life threatening! No cardiac output, ventricles
are fluttering. Lethal if not reversed in 3-5 mins
EKG
• https://www.pinterest.com/pin/343188434080423067/
Possible Heart Rhythms
• Interference seen on the monitor or rhythm strip
• May look like wandering or fuzzy baseline
• Can be caused by patient movement, poor electrode connection, improper
grounding, faulty equipment
Artifact
• Some artifact can appear as lethal arrythmias
• Toothbrushing = V-Tach
• Tapping on electrode = V-Fib
Artifact