Telemetry Med Surg Exam 3 Study Guide
sinus node Correct Answer-The intrinsic pacemaker. Cell membrane
"leakiness" causes spontaneous depolarization at a rate of 60-100 times a
minute.
AV node Correct Answer-Acts like a resistor to slow the impulse
allowing time for the atria to completely contract before initiating
ventricular contraction. Back up pacemaker if SA fails, pacing at a rate
of 40-60 times a minute.
Bundle of his Correct Answer-"Cable" that passes through the fibrous
sheath separating atria from ventricles. Divides into the bundle branches.
Bundle branches Correct Answer-"Wires" that run down the septum and
into the ventricles. There are two left bundle branches and one right.
Purkinje Correct Answer-Terminal fibers branches from the bundles,
distributing the impulse throughout the ventricles.
Intranodal pathways Correct Answer-"Wiring" that allows rapid impulse
movement around the atria to coordinate simultaneous atria contraction
Impulse vectors Correct Answer-SA node
Atria
AV node
,The depolarization wave in the ventricles also travel in specific
directions forming vectors. Because the left ventricle has a bigger
muscle mass, the wave of depolarization (starts in mid septum) is greater
than the right and is represented as a bigger vector.
which ventricle has bigger muscle mass Correct Answer-left ventricle
degree of perpendicular Correct Answer-If the current is running at an
angle to the field, the angulation is seen as so much positive and so
much negative depending on how parallel and perpendicular the current
vector is to the field. The degree of perpendicular can also be seen as a
decrease in amplitude only.
leads Correct Answer-
PQRST Correct Answer-
P wave Correct Answer-ATRIAL DEPOLARIZATION
Normal: small, round, positive in lead II
amplitude 0.5-2.5 mm, 0.10 seconds or less
p wave amplitude and time Correct Answer-0.5-2.5 mm
, 0.10 s
abnormally shaped P wave indicates Correct Answer-damaged atria
(enlarged makes p wave look like an "m") or an impulse origin outside
of the SA node (ectopic)
notching in P wave indicates Correct Answer-atrial enlargement (p
mitrale)
PR interval normal length Correct Answer-0.12-.20s
PR interval Correct Answer-Start: beginning of P
End: beginning of QRS
atrial depolarization and pause before QRS (AV node delay)
current traveling quickly down the His and purkinjes
shortened PRI Correct Answer-bypass pathway or the impulse origin
was ectopic and close to the AV node
long PRI Correct Answer-delays at the AV or His
sinus node Correct Answer-The intrinsic pacemaker. Cell membrane
"leakiness" causes spontaneous depolarization at a rate of 60-100 times a
minute.
AV node Correct Answer-Acts like a resistor to slow the impulse
allowing time for the atria to completely contract before initiating
ventricular contraction. Back up pacemaker if SA fails, pacing at a rate
of 40-60 times a minute.
Bundle of his Correct Answer-"Cable" that passes through the fibrous
sheath separating atria from ventricles. Divides into the bundle branches.
Bundle branches Correct Answer-"Wires" that run down the septum and
into the ventricles. There are two left bundle branches and one right.
Purkinje Correct Answer-Terminal fibers branches from the bundles,
distributing the impulse throughout the ventricles.
Intranodal pathways Correct Answer-"Wiring" that allows rapid impulse
movement around the atria to coordinate simultaneous atria contraction
Impulse vectors Correct Answer-SA node
Atria
AV node
,The depolarization wave in the ventricles also travel in specific
directions forming vectors. Because the left ventricle has a bigger
muscle mass, the wave of depolarization (starts in mid septum) is greater
than the right and is represented as a bigger vector.
which ventricle has bigger muscle mass Correct Answer-left ventricle
degree of perpendicular Correct Answer-If the current is running at an
angle to the field, the angulation is seen as so much positive and so
much negative depending on how parallel and perpendicular the current
vector is to the field. The degree of perpendicular can also be seen as a
decrease in amplitude only.
leads Correct Answer-
PQRST Correct Answer-
P wave Correct Answer-ATRIAL DEPOLARIZATION
Normal: small, round, positive in lead II
amplitude 0.5-2.5 mm, 0.10 seconds or less
p wave amplitude and time Correct Answer-0.5-2.5 mm
, 0.10 s
abnormally shaped P wave indicates Correct Answer-damaged atria
(enlarged makes p wave look like an "m") or an impulse origin outside
of the SA node (ectopic)
notching in P wave indicates Correct Answer-atrial enlargement (p
mitrale)
PR interval normal length Correct Answer-0.12-.20s
PR interval Correct Answer-Start: beginning of P
End: beginning of QRS
atrial depolarization and pause before QRS (AV node delay)
current traveling quickly down the His and purkinjes
shortened PRI Correct Answer-bypass pathway or the impulse origin
was ectopic and close to the AV node
long PRI Correct Answer-delays at the AV or His
