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88 Cards in this Set

  • Front
  • Back
In hyperkalemia, what happens as the potassium levels begin to rise?
T waves across the entire 12 lead EKG begin to peak
What is one difference between infarction-induced peaked T waves and those associated with hyperkalemia?
hyperkalemia: diffuse changes, all leads

infarction: confined to leads overlying the site
With further increases in the serum potassium, the PR interval becomes ______, and the P wave gradually ______ and then ______.
In advanced hyperkalemia, the QRS complex widens until it merges with the T wave, forming a ______ pattern.
sine wave
Ultimately, if hyperkalemia is left untreated, ______ may occur with devastating suddenness.
EKG progression of hyperkalemia (in four steps)
(1) peaked Ts (all leads)

(2) Prolonged, flattening PR and finally no P waves (all leads)

(3) sine waves

(4) V-fib
True or False:
EKG manifestations of hyperkalemia can be managed conservatively.
Any change in EKG due to hyperkalemia mandates immediate clinical attention!
True or False:
In both hyperkalemia and hypokalemia, bloodwork is a better indicator than EKG.
The EKG may be a better measure of serious toxicity than serum potassium levels.
Name the three changes that can be seen in hypokalemia:
(1) ST depression
(2) Flattening of the T wave
(3) Appearance of a U wave
True or False:
In hypokalemia, U waves almost always appear as tiny ripples after the T wave.
In many cases, the U waves are even more prominent than the T waves.
The term "U wave" is given to a wave appearing after the ______ wave in the cardiac cycle.
True or False:
U waves are diagnostic of hypokalemia.
Although U waves are the most characteristic feature of hypokalemia, they are not in and of themselves diagnostic.
True or False:
U waves are virtually always indicative of cardiac problems that require aggressive clinical intervention.
U waves can sometimes be seen in patients with normal hearts and normal serum potassium levels.
Aberations in the serum calcium levels primarily affect the ______.
QT interval
Hypocalcemia ______ the QT interval.
Hypercalcemia ______ the QT interval.
Hypocalcemia, by prolonging the QT interval, puts the patient at risk of ______.
Torsades de Pointes
(R-on-T lethal arrhythmia)
______, a variant of V-tach, is seen in patients with prolonged QT intervals.
Torsades de Pointes
In hypothermia, as the body temperature drops below ______ degrees C, several changes occur on EKG.
Name five EKG characteristics of hypothermia.
(1) Osborne waves (J waves)
(2) prolonged intervals
(3) sinus bradycardia
(4) slow atrial fib
(5) muscle tremor artifact
True or False:
In Hypothermia, everything on EKG speeds up.
Everything slows down.
In hypothermia, a distinctive and virtually ______ type of ST segment ______ may be seen.

ST segment configuration in hypothermia is known as ______ or ______.
J wave

Osborn wave
Of all arrhythmias associated with hypothermia, ______ is the most common.
slow atrial fibrillation
In hypothermic tracings, do not confuse shivering with ______.
atrial flutter
The two distinct EKG alterations caused by digitalis are ______ and ______.

Therapeutic levels of digitalis produce characteristic ST segment and T wave changes in most individuals taking the drug, known as the ______.
digitalis effect
describe the digitalis effect on EKG
(1) ST segment depression, gradual downslope that emerges almost imperceptibly from the preceding R wave

(2) flattening or inversion of T waves
True or False:
Changes associated with ventricular hypertrophy and the digitalis effect are always distinct.
differentiation can be difficult, especially since many patients on digitalis have CHF and left ventricular hypertrophy
True or False:
The digitalis effect is a medical emergency.
The digitalis effect is normal and predictable and does not necessitate discontinuing the drug.
The digitalis effect is most prominent in leads with _______.
tall R waves
Toxic manifestations of digitalis toxicity may require ______.
clinical intervention
Digitalis intoxication can elicit ______ and ______, alone or in combination.
conduction blocks

List four major electrical disturbances associated with digitalis toxicity.
(1) sinus node suppression
(2) conduction blocks
(3) tachyarrhythmias
(4) combinations (of all disturbances)
Even at therapeutic blood levels of digitalis, the sinus node can be ______.
At toxic digitalis blood levels, sinus ________ can occur.
(sinus exit block)
Since digitalis slows conduction through the AV node, ________ AV blocks can occur.
1st, 2nd, and 3rd degree
True or False:
Beta blockers may control rate better than digitalis in cases where exercise or stress is an issue.
True or False:
digitalis enhances automaticity of all cardiac cells.
True or False:
There is virtually no tachyarrhythmia that digitalis toxicity cannot cause.
From the most common to the least common, list three rhythm disturbances known to result from digitalis toxicity.
(1) PAT and PVCs (most common)
(2) Junctional
(3) A-fib/A-flutter (least common)
What is the most characteristic rhythm disturance of digitalis toxicity.
combination: PAT/2nd-degree AV block
What is the most common, but not the only, cause of PAT with block?
digitalis toxicity
a commmonly used anti-arrhythmic drug that increases the QT interval and therefore can paradoxically increase the risk for ventricular tachyarrhythmias
Solatol should be stopped if substantial -- usually more than ____% -- QT prolongation occurs.
Drugs that increase the QT interval can paradoxically increase the risk for ___________.
ventricular tachyarrhythmias
(such as torsades de pointes)
Name five specific antiarrhythmic agents known to increase the QT interval.
In some patients taking quinidine, prominent _______ may develop, but these do not require any adjustment in drug dosage.
U waves
True or False:
Several inherited disorders of cardiac repolarization are associated with long QT intervals -- some requiring medical intervention due to high risk of developing lethal arrhythmias.
Risk of developing a lethal arrhythmia in connection with an inherited disorder is greatest in ______ and ______.

early adulthood
Patients with QT prolonging inherited disorders must avoid this type of exercise.
"adrenalin burst" exercise
Patients with QT prolonging inherited disorders must avoid these types of drugs.
any drug that can prolong QT interval
Because the QT interval varies with heart rate, a __________, or _____, is used to assess absolute QT prolongation.
corrected QT interval

The _____ adjusts for differences in the heart rate by dividing the QT interval by the square root of the R-R interval, that is, one cardiac cycle.
to arrive at the QTc...
divide QT interval by square root of R-R interval
Rule: The QTc should not exceed _______ during therapy with any drug that can prolong the QT interval (______ if there is an underlying bundle branch block); adhering to this rule will reduce the risk for ______.
500 ms
(550 ms)

ventricular arrhythmias
Acute pericarditis may cause ST segment ______ and T wave ______ or ______.

True or False:
EKG changes in acute pericarditis can easily be confused with an evolving infarction, as can the clinical picture.
four characteristics that help differentiate pericarditis from infarction
In pericarditis (but not infarction):

(1) diffuse EKG changes, not site specific

(2) T inversion *after* ST returns to baseline

(3) no Q waves

(4) PR interval sometimes depressed
cardiac condition that dampens the electrical output of the heart, resulting in low voltage in all leads
pericardial effusion
What may happen to the position of the heart if a pericardial effusion is sufficiently large?
It may actually rotate freely within the fluid-filled sac.
Phenomenon in which the electrical axis varies with each beat, as with a freely rotating heart in severe pericardial effusion
electrical alternans
How is electrical alternans most easily recognized on EKG?
varying amplitude of each waveform from beat to beat
Hypertrophic Obstructive Cardiomyopathy
HOCM was formerly known as
idiopathic hypertrophic subaortic stenosis
Many patients with HOCM have normal EKGs, but ______ and ______ are not uncommon.
left ventricular hypertrophy

left axis deviation
non-infarct condition that may cause Q waves to be seen laterally and occasionally inferiorly
In HOCM, Q waves may be seen ______ and occasionally ______.

True or False:
Q wave in the presence of HOCM is diagnostic of true infarction.
In HOCM, Q waves may sometimes be seen laterally and occasionally inferiorly; these Q waves do not represent infarction.
True or False:
Inflammation of the myocardium is virtually never detectable on EKG.
Any diffuse inflammatory process involving the myocardium can produce a number of changes on EKG.
most common EKG changes associated with myocarditis
conduction blocks
(especially bundle branch and hemiblocks)
three things that the EKG of a patient with longstanding emphysema may show
(1) low voltage
(2) right axis deviation
(3) poor R wave progression
In COPD, low voltage on EKG is caused by this.
the dampening effects of the expanded residual volume of air trapped in the lungs
In COPD, right axis deviation on EKG is caused by these two factors.
(1) expanded lungs forcing the heart into a verticle or even rightward-oriented position

(2) pressure overload hypertrophy from pulmonary hypertension
condition that can lead to chronic cor pulmonale and right-sided CHF
condition in which the EKG may show right atrial enlargement (P pulmonale) and right ventricular hypertrophy with repolarization abnormalities
True or False:
A sudden massive pulmonary embolus can profoundly alter the EKG.
Massive acute pulmonary embolus may include these four EKG findings
(1) Right ventricular hypertrophy with repolarization changes (due to dilation)

(2) RBBB

(3) S1Q3 pattern (large S in lead I, deep Q in lead III)

(4) Arrhythmias (most common are sinus tach and a-fib)
Name for pattern associated with acute pulmonary embolism involving leads I and III
In S1Q3, the T wave in lead III may be ______.
Unlike inferior infarction, in which Q waves are usually seen in at least two of the inferior leads, the Q waves in an acute pulmonary embolus are generally limited to ______.
lead III
True or False:
The EKG in a nonmassive pulmonary embolus is normal in most patients, or it may show sinus tach.
CNS catastrophes, such as subarachnoid bleed or cerebral infarction, can produce diffuse _______ and prominent _______.
T wave inversion

U waves
Inverted T waves associated with catastrophic CNS events are typically _______ and ______.
very deep

very wide
rhythm commonly seen in the presence of CNS catastrophes
sinus bradycardia
EKG changes in connection with CNS events are believed to be due to the involvement of the _________.
autonomic nervous system
True or False:
Marathon runners and other athletes involved in endurance training can develop harmless alterations in their EKG's that may be mistaken for serious conditions.
Name six EKG changes that may be seen in an athlete's heart.
(1) sinus brady below 30

(2) ST/T changes -- typically ST elevation and T flattening or inversion on precordials

(3) left or right ventricular hypertrophy

(4) incomplete RBBB

(5) various arrhythmias, including junctional and wandering atrial pacemaker

(6) 1st degree or Wencheback AV block