Week 10 - Study Guide Flashcards
P-wave
- atrial depolarization initiated by the SA node
(the spreading of the electrical signal (depolarization) through the atria)
Pause after P wave and before QRS complex
- Atrial depolarization complete, the impulse is delayed at the AV node
QRS complex
- Ventricular depolarization begins at the apex, causing the QRS complex.
Atrial Repolarization occurs.
When the QRS wave initiates - that is the signal (depolarization phase) spreading down the bundle of His, and up the Purkinje fibers.
It covers up the repolarization phase of the atria.
Ventricular depolarization is complete after_____
the QRS complex - before the T wave
- once the ventricle is get the electrical signal (depolarization) is able to go through contraction
T- wave
- Ventricular repolarization of the ventricle begins at the apex, causing the T wave.
Repolarization phase will occur in the ventricles
Line after T wave
- Ventricular repolarization is complete
Common symptoms of heart attack (myocardial infarction)
- Crushing pain in chest (50%) or squeezing sensation
- Nagging discomfort, achy pain under shoulder blade, along clavicle, or jaw
- Cold sweats
- Shortness of breath at rest
- Nausea
- Episodes of dizziness and lightheadedness
Heart block is a
disorder of the hearts electrical system
1st-degree heart block
- asymptomatic - found on EKG as delayed transmission
person not aware
2nd-degree heart block
- arrhythmias
- skipped beats
- periodic absence of QRS wave
- AV node does not always respond
P-wave –> no QRS complex –> no T-wave
T-wave only occurs at the repolarization of the ventricles
So - you get a P-wave and then a flat line until the next P-wave occurs
Not life-threatening but the person would be aware of it
3rd-degree heart block
- Life-threatening
- Requires a PACEMAKER
- can lead to heart failure
The signals being sent by the pacemaker are not being responded to appropriately. SO - replacement of the pacemaker is essential to keep the signaling in the heart going so the heart will continue to function as an appropriate pump
4 types of Circulatory shock
- Cardiogenic
- Hypovolemic
- Vasodilatory (Vasogenic)
- Neurogenic
Hypovolemic Shock
- Blood volume loss (hemorrhage or bleeding ulcer)
- Fluid loss - fluid out of circulation means you do not have enough blood volume
Low arterial pressure (circulatory shock
Low cardiac output
Low blood volume due to loss of blood and/or loss of body fluids
Cardiogenic shock
- Cardiac output is insufficient (myocardial infarction)
A heart problem that is now creating insufficient cardiac output
In the beginning where the formation occurred - at the level of the heart itself
Vasogenic Shock
- Vasodilation - cannot get blood back to the heart
- vascular tone is lost
- blood vessels relax
usually due to septic shock & spinal cord injury
Blood volume is normal but the blood is not being delivered appropriately.
Due to the loss of vascular tone we do not have enough blood to send equally to all places of the body at the same time.
So- we have to reduce the amount of blood flow to some regions to get blood to others
Can result in Anaphylactic shock and Septic shock