Ch 42: Principals Of Electrocardiography Flashcards
The two upper chambers of the heart
Atria
The part of the cardiac conduction system between the atria and the ventricles
Atrioventricular node
AV node
Specialized muscle fibers that conduct electrical impulses from the AV node to the ventricular myocardium.
Bundle of His
I can decision in which cardiac contractions stop completely.
Cardiac arrest
The use of electroshock to convert an abnormal cardiac rhythm into a normal one
Cardioversion
A machine that delivers and electroshock to the heart through electrodes placed on the chest wall
Defibrillator
The period of relaxation of the chambers of the heart, during which blood enters the heart from the vascular system and the lungs.
Diastole
Originating outside the normal tissue.
Ectopic
An area of tissue that has died from lack of blood supply.
Infarction
Decreased blood flow to a body parts or Oregon, caused by construction or blockage of the supplying artery.
Ischemia
Electrical connections attached to the body to record electrical heart activity; any of the conductors connected to the electrocardiograph, each comprising two or more electrodes that are attached at specific body sites and it used to examine and record the electrical activity of the heart.
Leads
Pertaining to the heart muscle
Myocardial
Pounding or racing of the heart; it may or may not indicate a serious heart disorder.
Palpitations
The pacemaker of the heart, located in the right atrium
Sinoatrial node
SA node
The period of contraction of the heart.
Systole
To lower chambers of the heart.
Ventricles
A Dutch physiologist who developed Techniques to record the electrical activity of the heart in the late 1800s
William Einthoven
Heart activity: Atrial contraction
Electrical current: Atrial depolarization
P wave
Heart activity: Contraction transversing the atrioventricular node
Electrical current: Depolarization transversing the AV node
PR interval
Heart activity: Ventricular contraction; electrical stimulation travels from the AV node to the Purkinje fibers.
Electrical current: Ventricular depolarization and atrial repolarization
QRS complex
Heart activity: Time interval between ventricular contraction and the beginning of the ventricular recovery
Electrical current: Time interval between ventricular contraction and the beginning of the ventricular repolarization
ST segment
Heart activity: Ventricular contraction subsides
Electrical current: ventricularrepolarization; atrial polarization begins
T wave
Heart activity: Associated with further ventricular relaxation
Electrical current: Purkinje fibers repolarization
U wave
Heart activity: The heart at rest
Electrical current: Ventricular and atrial polarization
Baseline
Heart activity: Time interval between atrial contraction and ventricular contraction; electrical stimulation travels from the SA noads to the AV nodes.
Electrical current: Time interval between atrial depolarization and ventricular depolarization
PR interval
Heart activity: Time interval between the beginning of ventricular contraction and the subsiding of ventricular contraction; electrical stimulation travels from the AV node to the Purkinje fibers
Electrical current: Time interval between the beginning of ventricular depolarization and ventricular repolarization (electrical recovery)
QT interval
