ECG's Flashcards
What are the signs and symptoms of cardiac disease?
Dyspnea, chest pain, SOB, palpations, weakness, lethargy, or syncope
What is Polarized?
The resting state or the state in which there is no electrical activity.
What is depolarization?
When stimulation of the polarized cells causes an influx of Na+ into the interior portion of the cell. Depolarization causes the cardiac muscles to contract.
The electrical impulse system has 3 types of cardiac cells capable of electrical excitation, what are they called?
1.Pacemaker cells (SA node, AV node)
2. Purkinjie Fibers
3. Atrial and Ventricular muscle cells
The impulse conducting system is responsible for what?
Initiating the heartbeat and controlling the heart rate, and also controls the contraction of the heart chambers.
Where is the SA node located?
Upper right atrium
Of the 3 electrical impulses (Pacemaker SA ,AV, Purkinjie fibers, Atrial and ventricular muscle cells) which has the greatest degree of automaticity and paces the heart?
SA Node
Any heartbeat originating outside of the SA node is considered what?
Ectopic
The SA node is innervated by what?
The Autonomic Nervous System which allows the sympathetic and parasympathetic to influence the heart rate.
This is considered the backup pacemaker because it has the 2nd greatest degree of automaticity
The AV node and paces ventricular activity at a lower heart rate of 40 to 60 BPM.
Why is the electrical impulse temporarily delayed at the AV node?
It allows time for the ventricle to fill with blood.
Where is the AV node located?
It is located in the interventricular septum.
What stimulates contraction of the myocardium?
The Purkinje fibers
What happens when the atrium and the ventricles contract?
The blood moves
What is the function of the Purkinje Fibers?
The Purkinje Fibers stimulate contraction of the myocardium causing a coordinated contraction of the ventricles.
What leads are bipolar?
The Limb leads 1,2,3,