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88 Cards in this Set
- Front
- Back
In hyperkalemia, what happens as the potassium levels begin to rise?
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T waves across the entire 12 lead EKG begin to peak
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What is one difference between infarction-induced peaked T waves and those associated with hyperkalemia?
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hyperkalemia: diffuse changes, all leads
infarction: confined to leads overlying the site |
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With further increases in the serum potassium, the PR interval becomes ______, and the P wave gradually ______ and then ______.
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prolonged
flattens disappears |
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In advanced hyperkalemia, the QRS complex widens until it merges with the T wave, forming a ______ pattern.
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sine wave
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Ultimately, if hyperkalemia is left untreated, ______ may occur with devastating suddenness.
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V-fib
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EKG progression of hyperkalemia (in four steps)
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(1) peaked Ts (all leads)
(2) Prolonged, flattening PR and finally no P waves (all leads) (3) sine waves (4) V-fib |
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True or False:
EKG manifestations of hyperkalemia can be managed conservatively. |
False.
Any change in EKG due to hyperkalemia mandates immediate clinical attention! |
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True or False:
In both hyperkalemia and hypokalemia, bloodwork is a better indicator than EKG. |
False.
The EKG may be a better measure of serious toxicity than serum potassium levels. |
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Name the three changes that can be seen in hypokalemia:
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(1) ST depression
(2) Flattening of the T wave (3) Appearance of a U wave |
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True or False:
In hypokalemia, U waves almost always appear as tiny ripples after the T wave. |
False.
In many cases, the U waves are even more prominent than the T waves. |
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The term "U wave" is given to a wave appearing after the ______ wave in the cardiac cycle.
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T
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True or False:
U waves are diagnostic of hypokalemia. |
False.
Although U waves are the most characteristic feature of hypokalemia, they are not in and of themselves diagnostic. |
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True or False:
U waves are virtually always indicative of cardiac problems that require aggressive clinical intervention. |
False.
U waves can sometimes be seen in patients with normal hearts and normal serum potassium levels. |
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Aberations in the serum calcium levels primarily affect the ______.
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QT interval
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Hypocalcemia ______ the QT interval.
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prolongs
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Hypercalcemia ______ the QT interval.
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shortens
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Hypocalcemia, by prolonging the QT interval, puts the patient at risk of ______.
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Torsades de Pointes
(R-on-T lethal arrhythmia) |
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______, a variant of V-tach, is seen in patients with prolonged QT intervals.
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Torsades de Pointes
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In hypothermia, as the body temperature drops below ______ degrees C, several changes occur on EKG.
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30
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Name five EKG characteristics of hypothermia.
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(1) Osborne waves (J waves)
(2) prolonged intervals (3) sinus bradycardia (4) slow atrial fib (5) muscle tremor artifact |
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True or False:
In Hypothermia, everything on EKG speeds up. |
False.
Everything slows down. |
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In hypothermia, a distinctive and virtually ______ type of ST segment ______ may be seen.
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diagnostic
elevation |
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ST segment configuration in hypothermia is known as ______ or ______.
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J wave
Osborn wave |
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Of all arrhythmias associated with hypothermia, ______ is the most common.
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slow atrial fibrillation
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In hypothermic tracings, do not confuse shivering with ______.
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atrial flutter
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The two distinct EKG alterations caused by digitalis are ______ and ______.
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therapeutic
toxic |
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Therapeutic levels of digitalis produce characteristic ST segment and T wave changes in most individuals taking the drug, known as the ______.
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digitalis effect
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describe the digitalis effect on EKG
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(1) ST segment depression, gradual downslope that emerges almost imperceptibly from the preceding R wave
(2) flattening or inversion of T waves |
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True or False:
Changes associated with ventricular hypertrophy and the digitalis effect are always distinct. |
False.
differentiation can be difficult, especially since many patients on digitalis have CHF and left ventricular hypertrophy |
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True or False:
The digitalis effect is a medical emergency. |
False.
The digitalis effect is normal and predictable and does not necessitate discontinuing the drug. |
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The digitalis effect is most prominent in leads with _______.
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tall R waves
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Toxic manifestations of digitalis toxicity may require ______.
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clinical intervention
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Digitalis intoxication can elicit ______ and ______, alone or in combination.
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conduction blocks
tachyarrhythmias |
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List four major electrical disturbances associated with digitalis toxicity.
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(1) sinus node suppression
(2) conduction blocks (3) tachyarrhythmias (4) combinations (of all disturbances) |
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Even at therapeutic blood levels of digitalis, the sinus node can be ______.
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slowed
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At toxic digitalis blood levels, sinus ________ can occur.
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block
(sinus exit block) |
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Since digitalis slows conduction through the AV node, ________ AV blocks can occur.
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1st, 2nd, and 3rd degree
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True or False:
Beta blockers may control rate better than digitalis in cases where exercise or stress is an issue. |
True.
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True or False:
digitalis enhances automaticity of all cardiac cells. |
True.
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True or False:
There is virtually no tachyarrhythmia that digitalis toxicity cannot cause. |
True.
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From the most common to the least common, list three rhythm disturbances known to result from digitalis toxicity.
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(1) PAT and PVCs (most common)
(2) Junctional (3) A-fib/A-flutter (least common) |
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What is the most characteristic rhythm disturance of digitalis toxicity.
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combination: PAT/2nd-degree AV block
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What is the most common, but not the only, cause of PAT with block?
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digitalis toxicity
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a commmonly used anti-arrhythmic drug that increases the QT interval and therefore can paradoxically increase the risk for ventricular tachyarrhythmias
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Sotalol
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Solatol should be stopped if substantial -- usually more than ____% -- QT prolongation occurs.
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25%
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Drugs that increase the QT interval can paradoxically increase the risk for ___________.
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ventricular tachyarrhythmias
(such as torsades de pointes) |
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Name five specific antiarrhythmic agents known to increase the QT interval.
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quinidine
procainamide disopyramide amiodarone dofetilide |
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In some patients taking quinidine, prominent _______ may develop, but these do not require any adjustment in drug dosage.
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U waves
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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. |
True.
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Risk of developing a lethal arrhythmia in connection with an inherited disorder is greatest in ______ and ______.
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childhood
early adulthood |
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Patients with QT prolonging inherited disorders must avoid this type of exercise.
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"adrenalin burst" exercise
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Patients with QT prolonging inherited disorders must avoid these types of drugs.
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any drug that can prolong QT interval
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Because the QT interval varies with heart rate, a __________, or _____, is used to assess absolute QT prolongation.
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corrected QT interval
QTc |
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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.
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QTc
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to arrive at the QTc...
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divide QT interval by square root of R-R interval
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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 ______.
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500 ms
(550 ms) ventricular arrhythmias |
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Acute pericarditis may cause ST segment ______ and T wave ______ or ______.
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elevation
flattening inversion |
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True or False:
EKG changes in acute pericarditis can easily be confused with an evolving infarction, as can the clinical picture. |
True.
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four characteristics that help differentiate pericarditis from infarction
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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 |
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cardiac condition that dampens the electrical output of the heart, resulting in low voltage in all leads
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pericardial effusion
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What may happen to the position of the heart if a pericardial effusion is sufficiently large?
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It may actually rotate freely within the fluid-filled sac.
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Phenomenon in which the electrical axis varies with each beat, as with a freely rotating heart in severe pericardial effusion
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electrical alternans
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How is electrical alternans most easily recognized on EKG?
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varying amplitude of each waveform from beat to beat
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HOCM
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Hypertrophic Obstructive Cardiomyopathy
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HOCM was formerly known as
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idiopathic hypertrophic subaortic stenosis
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Many patients with HOCM have normal EKGs, but ______ and ______ are not uncommon.
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left ventricular hypertrophy
left axis deviation |
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non-infarct condition that may cause Q waves to be seen laterally and occasionally inferiorly
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HOCM
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In HOCM, Q waves may be seen ______ and occasionally ______.
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laterally
inferiorly |
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True or False:
Q wave in the presence of HOCM is diagnostic of true infarction. |
False.
In HOCM, Q waves may sometimes be seen laterally and occasionally inferiorly; these Q waves do not represent infarction. |
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True or False:
Inflammation of the myocardium is virtually never detectable on EKG. |
False.
Any diffuse inflammatory process involving the myocardium can produce a number of changes on EKG. |
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most common EKG changes associated with myocarditis
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conduction blocks
(especially bundle branch and hemiblocks) |
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three things that the EKG of a patient with longstanding emphysema may show
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(1) low voltage
(2) right axis deviation (3) poor R wave progression |
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In COPD, low voltage on EKG is caused by this.
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the dampening effects of the expanded residual volume of air trapped in the lungs
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In COPD, right axis deviation on EKG is caused by these two factors.
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(1) expanded lungs forcing the heart into a verticle or even rightward-oriented position
(2) pressure overload hypertrophy from pulmonary hypertension |
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condition that can lead to chronic cor pulmonale and right-sided CHF
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COPD
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condition in which the EKG may show right atrial enlargement (P pulmonale) and right ventricular hypertrophy with repolarization abnormalities
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COPD
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True or False:
A sudden massive pulmonary embolus can profoundly alter the EKG. |
True.
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Massive acute pulmonary embolus may include these four EKG findings
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(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) |
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Name for pattern associated with acute pulmonary embolism involving leads I and III
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S1Q3
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In S1Q3, the T wave in lead III may be ______.
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inverted
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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 ______.
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lead III
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True or False:
The EKG in a nonmassive pulmonary embolus is normal in most patients, or it may show sinus tach. |
True.
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CNS catastrophes, such as subarachnoid bleed or cerebral infarction, can produce diffuse _______ and prominent _______.
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T wave inversion
U waves |
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Inverted T waves associated with catastrophic CNS events are typically _______ and ______.
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very deep
very wide |
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rhythm commonly seen in the presence of CNS catastrophes
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sinus bradycardia
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EKG changes in connection with CNS events are believed to be due to the involvement of the _________.
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autonomic nervous system
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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. |
True.
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Name six EKG changes that may be seen in an athlete's heart.
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(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 |