basic ekg Flashcards
The heart has the innate ability to generate its own spontaneous action potentials without any external stimuli, a phenomenon known
as automaticity.
The rate at which the pacemaker cells fire is
HR
The pacemaker cells do not have a true ___ in their action potential cycle.
The pacemaker cells do not have a true “resting phase” in their action potential cycle.
The contractile cells make up ____ of the myocardium
The contractile cells make up the bulk of the myocardium 99%
what do you give for hyperkalemia
calcium to stabilize the cell membrane
____is the primary pacemaker that produces spontaneous action potentials that will determine the heart rate.
the SA node is the primary pacemaker that produces spontaneous action potentials that will determine the heart rate.
is located at the back of the right atrium near the superior vena cava entry.
SA node
The action potential travels from the SA node through the right atrium via ___, and to the left atrium via ______
The action potential travels from the SA node through the right atrium via the internodal pathway, and to the left atrium via Bachmann’s bundle
the “gatekeeper” that sends the action potential from the atria to the ventricles.
AV node
The other important function of the AV node is that
slows down the conduction velocity of the action potential.
the transition from the end of diastole to the start of systole in the cardiac cycle
, the AV node
can assume what if you have a QRS more than 0.12 sec
ventricular in nature
After the action potential travels through the AV node it will enter___
bundle of His, also known as the atrioventricular bundle.
steps of conduction
- SA node
- internodal pathwya
- AV node
- Bundle of His
- R/L bundle branches
- Purkinje Fibers
SA node speed
60-100
bundle of his speed
40-60
AV node speed
40-60
bundle branch speed
20-40
purkinje fibers speed
20-40
primary cardiac stand still
all you have is P waves
qrs duration
0.08-0.12
P wave positive in what leads
I,
II,
aVF,
V4-V6
