What are cardiac dysrhythmias?
abnormal rhythms of the heart's electrical system that can affect its ability to effectively pump oxygenated blood
... [Show More] throughout the body
What are the two questions you ask yourself when you have a patient with a dysrhythmia?
1. Is the patient symptomatic? (diaphoresis, light headed, unresponsive, decreased LOC, decreased BP, tachy/brady)
2. Is the heart going to wear out keeping this up?
Electrical changes in cardiac cells primarily involve the movement of what across the cell membrane?
The movement of Na+, K+ and Ca++ across the cell membrane
What happens to the cardiac cells during the resting state (polarization)?
cells in ready state and no current is flowing
What happens to the cardiac cells during depolarization?
Na+ rushes into cell
↓
Ca++ enters slowly, as K+ leaves slowly
↓
This electrical activity stimulates cells to contract
What happens to the cardiac cells during repolarization?
cells return to resting state
What is the inherent rate of the SA node at rest?
60-100
Where is the SA node located?
Right atrium
After the SA node and the atria, where does the impulse go?
AV node
Describe the normal conduction pathway, step by step:
The sino-atrial (SA) node
↓
The atrio-ventricular (AV) node
↓
The bundle of His
↓
The left and right bundle branches
↓
The Purkinje fibres
Define automaticity:
the ability of myocardial cells to initiate electrical impulses
(the SA node, AV node, His-Purkinjie are considered to be the "pacemaker" cells)
Define excitability:
ability of the myocardial cells to respond to electrical stimulus
Define conductivity:
ability of the myocardial cells to receive electrical stimulus and send it on
Define contractility:
ability of myocardial cells to contract in response to electrical stimuli
Where does the white lead go when placing the 5 electrodes?
"White on the right" (underneath the clavicle)
Where does the black lead go when placing the 5 electrodes?
"Smoke above fire" (underneath the left clavicle)
Where does the red lead go when placing the 5 electrodes?
"Fire!" (below the smoke, or the black lead, at the base of the left rib cage)
Where does the green lead go when placing the 5 electrodes?
"Clouds above grass" (below the white and brown, at the base of the right rib cage, directly across from the red)
Where does the brown lead go when placing the 5 electrodes?
A dog taking a pooo below the white clouds onto the green grass below ahaha
What does the P wave represent?
atrial depolarization
What does the QRS represent?
ventricular depolarization
What does the T wave represent?
ventricular repolarization [Show Less]