Electrocardiogram Flashcards
What is an ECG
Electro_Cardio_gram
Deivice used on the surface of the body that can detect the electrical changes associated with stimulation of the atria and ventricles on the body’s surface
What does the contraction of the cardiac muscle result from?
a series of electrical potential changes that move rapidly through the heart (depolarization)
what is the cardiac muscle stimulated by
Intrinsic mechanisms
What does the INTRINSIC Conduction System do/ ensure?
Ensures that the cardiac muscle within the heart depolarizes in a SEQUENTIAL manner (atria to ventricles) so the heart can beat as a coordinated unit.
Components of the Intrinsic Conduction System
- Sinoatrial (SA) Node
- Atrioventricular (AV) Node
- AV Bundle (Bundle of HIS)
- Right and Left Bundles
- Purkinje Fibers
Location of Sinoatrial (SA) Node and nickname and speed
Within the right atrium, inferior to the superior vena cava opening
fastest intrinsic rate, and controlls the other parts of the conduction system. Called the hearts “Pacemaker”
Location of Atrioventricular (AV) Node
Base of Right Atrium, may take over if the SA NODE is not working properly
Location of AV Bundle (Bundle of HIS)
Interventricular septum
Location of Right and Left Bundles
Interventricular Septum
Location of Purkinje Fibers
Ventricular walls
ECG Electrodes are called
“Leads” that are places on the surface of the body on locations where it is easiest to pick up electrical signals from the heart
ORDER: 1 2 3 4
Depolarization
Contraction
Repolarization
Relaxation
P
P-Q segment
QRS Complex
- Atrial depolarization
- Atrial plateau, occures in sarcolemma od cardiac muscle cells when they are cotracted
- Ventricular depolarization
S-T segment
T
Ventricular plateau, when the muscles are being contracted
-Ventricular repolarizaiton
P-R Interval
Q-T Interval
Time it takes for depolarization to spread from SA node to AV node(.12-.2 seconds )
Time it takes for ventricles to depolarize and repolarize (.2-.4 seconds)
What is Cardiac Arrest?
How can it be casued?
- When the hearts electrical system malfunctions
- death results when heart stops working properly
- abnormal or irregular heart rhythms called ARRHYTHMIAS
Can cardiac arrest be reversed ?
YES! can be reversed if CPR is performed and a defibrillator is used to shock the heart and restore a normal heart rhythem within a few minuets
Oxygen Saturation? What is that
term referring to the fraction of oxygen-saturated hemoglobin relative to total HEMOGLOBNI (saturated + Unsaturated) in the blood
Oxygen-saturated hemoglobin/ Total Hemoglobin
Normal Blood Oxygen levels in humans are
95- 100 Percent
Pulse OXIMETRY
Medical Devise used to indirectly measure the oxygen saturation of a patients blood. rather then taking a blood sample.
Why would you use a pulse oximeter
people with COPD, Asthma, Congestive Heart Failure (CHF) and other conditions
