Made Ridiculously Simple Flashcards
SA node spontaneously fires—>
depolarization of atria –> contraction of atria
The electrical impulse then travels to the AV node, where it is help up by a built in delay before preceding to the..
Bundle of His and bundle branches
Finally, the electrical signal spreads across the ventricles by way of the…
Purkinje fibers
this causes the ventricles to contract as a unit
the ____ wave represents the electrical depolarization that occurs just prior to atrial contraction
P wave
Flat line (PR segment) between P wave and start of QRS complex represents
the time the impulse is held up at the AV node
The _____ ______ represents ventricular depolarization
QRS complex
The ___ wave represents ventricular repolarization
T wave
What wave is sometimes visible after the T wave, but not always
U wave
Which wave may represent further depolarization in the ventricle or repolarization of the Purkinje system
U wave
The U wave may become more prominent in..
Bradycardia OR electrolyte imbalance
Arrhythmias are classified by which 2 things?
Brady vs tachy
Location (atria vs ventricle)
HR less than 60 bpm
Bradycardia
Either a problem with the SA node OR a block somewhere in the conduction system may lead to…
Bradycardia
What type of person might bradycardia be normal?
Well trained athlete
- Normal physiologic response (i.e. sleep)
- Result of ischemia
- Certain drugs
- Increased vagal tone
Can all cause a decrease in SA node firing
First downward deflection on EKG
Q wave
First upward deflection of QRS complex
R wave
Any downward wave that occurs after the R (upward deflection) wave
S wave
If there are 2 upward deflections in a QRS complex, the second upward deflection is..
R prime
first one is R wave
P waves and QRS appear normal, but the number of P and QRS complexes per unit time will be decreased
Bradycardia
In ___ ____, the SA node pulses at its normal rate but the conduction is blocked somewhere along the route to the ventricles
heart block
Blocks can occur in:
AV node
Bundle of His
Bundle branches
First degree Second degree Mobitz type I (Wenckebach) Second degree Mobitz type II Third degree (aka complete)
Types of heart blocks
If some isolated ventricular cells produce an escape beat, the depolarization will spread in a less organized fashion, resulting in a..
Widened QRS complex
What does a prolonged PR interval represent?
First degree heart block
PR interval >0.2 seconds
First degree heart block
Under normal circumstances, QRS complex mostly represents
Left ventricle
PR interval represents the time that the impulse travels through the AV node. This interval is prolonged with a…
First degree heart block
Which valves are the AV valves?
Mitral
Tricuspid
Aortic and pulmonic valves lie between the _______ and their outflow vessels (aorta and pulmonary artery)
Ventricles
Pulmonic valve lies between the _____ ventricle and the pulmonary artery
Right
Aortic valve lies between the _____ ventricle and the aorta
Left
Tricuspid valve is on which side of heart?
Right
tRIcuspid, RIght side
Mitral (bicuspid) valve is on which side of heart?
Left
mitraL, Left side
During systole, the ventricles…
Contract
forcefully expelling blood into outflow vessels
During diastole, the ventricles..
Relax
ventricles fill with blood from the atria
Which valves are closed during systole?
AV valves (mitral and tricuspid) **this prevents back flow of this blood from the ventricles to the atria
Which valves are closed during diastole?
Aortic and pulmonic valves
**this prevents back flow of blood that has just been ejected during systole
Patients with _______ _______ may have:
- downsloping ST segment depression
- T wave inversion
ventricular hypertrophy
