PCC 4 Exam 1
magnesium and potassium - ✔️✔️the 2 electrolytes that affect the heart the most and
will most likely cause a dysrhythmia if they are abnormal
Depolarization (heart is Doing the work) - ✔️✔️release of energy resulting in
myocardial *contraction*
Repolarization (Relaxing, Recovering after a contraction) - ✔️✔️myocardial cells are
recovering/relaxing
P-wave - ✔️✔️represents atrial depolarization/contraction (sending blood to ventricles);
firing of SA node; represents conduction of electrical impulse through the atrium
atrial kick - ✔️✔️slight pause of impulse between SA and AV so the blood has time to
push into the ventricles
Purkinje fibers - ✔️✔️fibers in the ventricles that reach throughout the myocardium to
stimulate ventricular contraction
1. blood flow alteration --> decreased blood volume in the heart (hypovolemia, right
CHF and valve issues, COPD), decreased blood volume to coronary arteries
(clot/plaque), or decreased oxygen in the blood flow (PE, hypoxia)
2. electrolyte abnormalities
3. acid base imbalances
4. adverse drug effects - ✔️✔️common causes of conduction abnormalities of the heart
135-145 - ✔️✔️normal sodium levels
3.5-5.2 - ✔️✔️normal potassium levels
potassium - ✔️✔️electrolyte that affects the resting potential of the heart, affects the
heart the most when levels are off
acute renal failure
too much intake
acidosis - ✔️✔️causes of hyperkalemia
*tall peaked T waves!!*
bradycardia
v-fib
ventricular standstill - ✔️✔️what changes on the EKG may indicate hyperkalemia?
,fatigue
irritability
loss of muscle tone
muscle weakness, cramps
paresthesias
decreased reflexes
abdominal cramps, diarrhea, vomiting
confusion
irregular pulse
tetany - ✔️✔️manifestations of hyperkalemia
diuresis
*kayexelate*
IV insulin
IV calcium chloride or calcium gluconate - ✔️✔️treatments for hyperkalemia
diuresis
vomiting
diarrhea
NG suction
alkalosis
starvation
failure to include K+ in parenteral feedings - ✔️✔️causes of hypokalemia
flattened T wave
presence of U wave
peaked P wave
ventricular dysrhtyhmias
first and second degree blocks - ✔️✔️what changes can be seen on an EKG with
hypokalemia?
fatigue
muscle weakness, leg cramps
soft, flabby muscles
paresthesias, decreased reflexes
constipation, nausea, paralytic ileus
shallow respirations
weak, irregular pulse
hyperglycemia - ✔️✔️manifestations of hypokalemia
IV potassium chloride
increase dietary intake - ✔️✔️treatments for hypokalemia
8.2-10.6 - ✔️✔️normal calcium levels
,1.13-1.35 - ✔️✔️normal ionized calcium levels
SA node - ✔️✔️internal pacemaker of the heart, starts the heartbeat; located in the
right atrium; p-wave on an EKG
60-100 bpm - ✔️✔️how fast does the SA node beat the heart per min?
AV node - ✔️✔️relays electrical impulses from atria into ventricles, located directly
above the right ventricle
40bpm - ✔️✔️how fast will the AV node beat the heart if the SA node is not firing
correctly?
Bundle of His - ✔️✔️a bundle of modified heart muscle that transmits the cardiac
impulse from the atrioventricular node to the ventricles causing them to contract;
branches into left and right ventricles
ionized calcium - ✔️✔️which value of calcium is a more accurate representation of
calcium levels in the body, calcium (bound) or ionized calcium (free)?
1.6-2.6 - ✔️✔️normal magnesium levels
magnesium - ✔️✔️electrolyte that affects the contractility of the heart
false --> for ex: if patient is ordered a dose of Lasix and K+ level is 3.9 (normal), we are
likely going to give them a K+ supplement with the Lasix to ensure K+ stays in normal
limits - ✔️✔️T or F: we should wait until electrolytes are abnormally low before
replacing them to reduce the risk of having too high of levels
cardiac output, 20% - ✔️✔️an abnormal P wave compromises the atrial kick and leads
to a decrease ____ ____ by ___%
the atria are not contracting and there is a decreased CO, leading to decreased BP (ex:
in a-fib, a person is losing that good P-wave and solid atrial contraction, so they won't
have as good of CO) - ✔️✔️what does it mean when there is no P wave on the EKG?
0.06-0.12 seconds - ✔️✔️normal P-wave length
PR interval - ✔️✔️occurs from the onset of the P wave to the beginning of the QRS
complex; represents activity from the beginning of atrial depolarization to the beginning
of ventricular depolarization; the amount of time it takes and impulse to travel from SA
node through the atria and AV node to bundle branches; delay of AV node to allow
filling of ventricles
, 0.12-0.20 seconds (3-5 small boxes) - ✔️✔️What is the normal PR interval?
the impulse of the heartbeat is not coming from the SA node - ✔️✔️what does a short
PR interval indicate?
the impulse is delayed - ✔️✔️what does a long PR interval indicate?
0.04 seconds - ✔️✔️Each 1mm (small) box on the ECG strip represents how much
time?
QRS complex - ✔️✔️ventricular depolarization and electrical conduction through the
ventricles; atrial repolarization is buried here
0.06-0.12 seconds/ <0.12 seconds - ✔️✔️what is the normal range for a QRS
complex?
slow impulse conduction (QRS is >0.12 seconds) - ✔️✔️what does a widened QRS
complex indicate?
QRS complex - ✔️✔️which part of the heartbeat on an EKG can we feel as our pulse?
ST segment - ✔️✔️represents the end of ventricular depolarization and the beginning
of ventricular repolarization; measured from the S wave of the QRS complex to the
beginning of the T wave
myocardial infarction (cardiac damage) - ✔️✔️an elevation or depression of the ST
segment on an EKG means what?
Flat line (isoelectric line) - ✔️✔️how should the ST segment look on a normal EKG?
0.12 seconds - ✔️✔️normal time for an ST segment
T wave - ✔️✔️ventricular repolarization; positive deflection is normal and changes in
this indicate electrolyte imbalances or cardiac ischemia
0.16 seconds - ✔️✔️normal T wave time
peaked T wave - ✔️✔️hallmark sign of hyperkalemia
T waves will appear peaked on EKG --> eventually impulses will slow and AV node will
take over --> results in bradycardia (AV node only pumps heart at 40bpm) -
✔️✔️explain how hyperkalemia leads to bradycardia
magnesium and potassium - ✔️✔️the 2 electrolytes that affect the heart the most and
will most likely cause a dysrhythmia if they are abnormal
Depolarization (heart is Doing the work) - ✔️✔️release of energy resulting in
myocardial *contraction*
Repolarization (Relaxing, Recovering after a contraction) - ✔️✔️myocardial cells are
recovering/relaxing
P-wave - ✔️✔️represents atrial depolarization/contraction (sending blood to ventricles);
firing of SA node; represents conduction of electrical impulse through the atrium
atrial kick - ✔️✔️slight pause of impulse between SA and AV so the blood has time to
push into the ventricles
Purkinje fibers - ✔️✔️fibers in the ventricles that reach throughout the myocardium to
stimulate ventricular contraction
1. blood flow alteration --> decreased blood volume in the heart (hypovolemia, right
CHF and valve issues, COPD), decreased blood volume to coronary arteries
(clot/plaque), or decreased oxygen in the blood flow (PE, hypoxia)
2. electrolyte abnormalities
3. acid base imbalances
4. adverse drug effects - ✔️✔️common causes of conduction abnormalities of the heart
135-145 - ✔️✔️normal sodium levels
3.5-5.2 - ✔️✔️normal potassium levels
potassium - ✔️✔️electrolyte that affects the resting potential of the heart, affects the
heart the most when levels are off
acute renal failure
too much intake
acidosis - ✔️✔️causes of hyperkalemia
*tall peaked T waves!!*
bradycardia
v-fib
ventricular standstill - ✔️✔️what changes on the EKG may indicate hyperkalemia?
,fatigue
irritability
loss of muscle tone
muscle weakness, cramps
paresthesias
decreased reflexes
abdominal cramps, diarrhea, vomiting
confusion
irregular pulse
tetany - ✔️✔️manifestations of hyperkalemia
diuresis
*kayexelate*
IV insulin
IV calcium chloride or calcium gluconate - ✔️✔️treatments for hyperkalemia
diuresis
vomiting
diarrhea
NG suction
alkalosis
starvation
failure to include K+ in parenteral feedings - ✔️✔️causes of hypokalemia
flattened T wave
presence of U wave
peaked P wave
ventricular dysrhtyhmias
first and second degree blocks - ✔️✔️what changes can be seen on an EKG with
hypokalemia?
fatigue
muscle weakness, leg cramps
soft, flabby muscles
paresthesias, decreased reflexes
constipation, nausea, paralytic ileus
shallow respirations
weak, irregular pulse
hyperglycemia - ✔️✔️manifestations of hypokalemia
IV potassium chloride
increase dietary intake - ✔️✔️treatments for hypokalemia
8.2-10.6 - ✔️✔️normal calcium levels
,1.13-1.35 - ✔️✔️normal ionized calcium levels
SA node - ✔️✔️internal pacemaker of the heart, starts the heartbeat; located in the
right atrium; p-wave on an EKG
60-100 bpm - ✔️✔️how fast does the SA node beat the heart per min?
AV node - ✔️✔️relays electrical impulses from atria into ventricles, located directly
above the right ventricle
40bpm - ✔️✔️how fast will the AV node beat the heart if the SA node is not firing
correctly?
Bundle of His - ✔️✔️a bundle of modified heart muscle that transmits the cardiac
impulse from the atrioventricular node to the ventricles causing them to contract;
branches into left and right ventricles
ionized calcium - ✔️✔️which value of calcium is a more accurate representation of
calcium levels in the body, calcium (bound) or ionized calcium (free)?
1.6-2.6 - ✔️✔️normal magnesium levels
magnesium - ✔️✔️electrolyte that affects the contractility of the heart
false --> for ex: if patient is ordered a dose of Lasix and K+ level is 3.9 (normal), we are
likely going to give them a K+ supplement with the Lasix to ensure K+ stays in normal
limits - ✔️✔️T or F: we should wait until electrolytes are abnormally low before
replacing them to reduce the risk of having too high of levels
cardiac output, 20% - ✔️✔️an abnormal P wave compromises the atrial kick and leads
to a decrease ____ ____ by ___%
the atria are not contracting and there is a decreased CO, leading to decreased BP (ex:
in a-fib, a person is losing that good P-wave and solid atrial contraction, so they won't
have as good of CO) - ✔️✔️what does it mean when there is no P wave on the EKG?
0.06-0.12 seconds - ✔️✔️normal P-wave length
PR interval - ✔️✔️occurs from the onset of the P wave to the beginning of the QRS
complex; represents activity from the beginning of atrial depolarization to the beginning
of ventricular depolarization; the amount of time it takes and impulse to travel from SA
node through the atria and AV node to bundle branches; delay of AV node to allow
filling of ventricles
, 0.12-0.20 seconds (3-5 small boxes) - ✔️✔️What is the normal PR interval?
the impulse of the heartbeat is not coming from the SA node - ✔️✔️what does a short
PR interval indicate?
the impulse is delayed - ✔️✔️what does a long PR interval indicate?
0.04 seconds - ✔️✔️Each 1mm (small) box on the ECG strip represents how much
time?
QRS complex - ✔️✔️ventricular depolarization and electrical conduction through the
ventricles; atrial repolarization is buried here
0.06-0.12 seconds/ <0.12 seconds - ✔️✔️what is the normal range for a QRS
complex?
slow impulse conduction (QRS is >0.12 seconds) - ✔️✔️what does a widened QRS
complex indicate?
QRS complex - ✔️✔️which part of the heartbeat on an EKG can we feel as our pulse?
ST segment - ✔️✔️represents the end of ventricular depolarization and the beginning
of ventricular repolarization; measured from the S wave of the QRS complex to the
beginning of the T wave
myocardial infarction (cardiac damage) - ✔️✔️an elevation or depression of the ST
segment on an EKG means what?
Flat line (isoelectric line) - ✔️✔️how should the ST segment look on a normal EKG?
0.12 seconds - ✔️✔️normal time for an ST segment
T wave - ✔️✔️ventricular repolarization; positive deflection is normal and changes in
this indicate electrolyte imbalances or cardiac ischemia
0.16 seconds - ✔️✔️normal T wave time
peaked T wave - ✔️✔️hallmark sign of hyperkalemia
T waves will appear peaked on EKG --> eventually impulses will slow and AV node will
take over --> results in bradycardia (AV node only pumps heart at 40bpm) -
✔️✔️explain how hyperkalemia leads to bradycardia
