Chapter 10: Miscellaneous Flashcards
What 3 important life-threatening syndromes can be detected from the EKG in relatively asymptomatic patients?
Brugada Syndrome
Wellens Syndrome
Long QT Syndrome
(p. 310)
What are the key EKG features of Brugada syndrome?
RBBB with ST elevation in V1, V2, and V3
p. 310
What are the key EKG features of Wellens syndrome and what do they suggest?
Marked T wave inversion in V2 and V3, suggest [left] anterior descending coronary stenosis
(p. 310)
What are the key EKG features of Long QT Syndrome? Implications?
QT interval longer than 1/2 of the cardiac cycle; this predisposes the patient to ventricular arrhythmias
(p. 310)
What treatment is indicated for Brugada Syndrome?
a pacer (AICD) (p. 310)
What treatment is indicated for Wellens syndrome?
angioplasty with stenting, or CABG
p. 310
How many forms of (hereditary) Long QT Syndrome are there?
6
p. 310
On EKG, COPD often produces…
What other conditions appear with the first feature?
…low voltage amplitude in all leads, and there is usually right axis deviation. Multifocal atrial tachycardia is also seen with COPD.
Low voltage in all leads appears in hypothyroidism and chronic constrictive pericarditis.
(p. 311)
With COPD, the right ventricle works against considerable __________, so there is usually some degree of _____ ___________ ___________ and therefore, associated _____ axis deviation. The example shows negative QRS’s in lead I.
resistance
right ventricular hypertrophy
right
(p. 311)
With pulmonary embolus, we usually see…
…a large S wave in lead I, ST depression in lead II, and a Q wave with inverted T wave in lead III. Remember: S1, Q3, T3
Pulmonary embolus also causes T wave inversion in V1 - V4, and frequently a RBBB.
(p. 312-313)
S1Q3T3 syndrome characterizes acute ___ _________ resulting from pulmonary embolus.
cor pulmonale
p. 312
Pulmonary embolus typically has a tendency toward…
…right axis deviation.
p. 312
With elevated serum potassium, the P wave ________ ____, the QRS complex ______, and the T wave becomes ______.
flattens down, widens, peaked
p. 314
In hyperkalemia, the P wave widens and flattens, and with extreme hyperkalemia, the P wave ______ __________.
nearly disappears.
p. 314
The QRS in hyperkalemia widens because…
…ventricular depolarization takes longer.
p. 314
In HYPOkalemia, the T wave becomes ____ or ________ and a _ ____ appears.
flat, inverted, U wave
p. 315
The U wave in hypokalemia becomes more…
…pronounced as the loss of K becomes more severe.
p. 315
Hypokalemia makes ventricular foci…
…and enhances the toxic effects of…
…extremely irritable,
…digitalis excess.
p. 315
Hypercalcemia ________ the QT interval, and hypocalcemia _______ it.
shortens prolongs (p. 316)
The reason you see a shorter QT interval in hypercalcemia is…
…because more calcium accelerates both ventricular depolarization and ventricular repolarization.
(p. 316)
Digitalis excess causes changes to the ST segment to give it the appearance of…
…Salvador Dali’s mustache.
p. 317
Digitalis produces a unique…
To best see this effect, look in lead that has…
…gradual, downward curving ST depression.
…no demonstrable S wave.
p. 317
Digitalis in therapeutic doses has a _______________ effect. With a sinus rhythm, it slows conduction, inhibits the AV Node’s receptiveness to multiple stimuli, and causes a more efficient ___________ ________.
parasympathetic
ventricular response.
(p. 317)
What type of foci are exceptionally sensitive to digitalis?
As a result, _________ ______ _____ are often the earliest warning sign that the digitalis level is elevated.
supraventricular foci, particularly atrial
premature atrial beats
(p. 318)
The 4 common EKG changes seen with excess digitalis are…
...atrial and junctional premature beats PAT with block sinus block AV blocks (p. 318)
Digitalis excess that continues to the point of toxicity can cause…
…tachy-arrhythmias and ventricular irritability.
p. 319
Quinidine causes widening of the _ ____ and it is often _______, and widening of the ___. There is often __ __________ with a _________ __. _ _____ may appear as well.
P wave, notched, QRS
ST depression, prolonged QT
U waves
(p. 320)
Most of the effects of quinidine that we see on EKG relate to its pharmacological effects on…
…sodium and potassium ion channels.
p. 320
Since quinidine can prolong the QT interval, worst case scenario would be…
…Torsades de pointes.
p. 320
In most cases of artificial pacemakers, the electrode lead wire is passed…
OR, sometimes the stimulating electrode is surgically attached to…
…transvenously into the right side of the heart…
epicardial surface of the heart.
p. 321
A demand pacer is programmed to be _________-__________ by normal sinus pacing.
overdrive-suppressed
p. 322
The ideal location of the tip electrode of a R ventricular pacemaker, is in the…
The resultant QRS complex has a…
…apex of the right ventricle.
…LBBB pattern with left axis deviation.
p. 324
The 3 possible pacemaker electrode positions in the right ventricle and their axes…
- ) below the pulmonic valve (right axis deviation)
- ) mid inflow tract (normal axis)
- ) right ventricular apex (left axis deviation)
(p. 324)
A heart transplant procedures leaves portions of the recipient patient’s “native” _____ in place.
atria
p. 327
Name the 4 classes of Antiarrhythmics according to the Vaughn Williams Classification System.
Class Ia, Ib, and Ic are all sodium channel blockers.
Class II is the beta-adrenergic blockers
Class III are the potassium channel blockers
Class IV are calcium channel blockers
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
Tricky one… which class of antiarrhythmics does sotalol belong to?
Barkley and Myers books says Class III, but it also has class II properties according to drugs.com
What are the common Class I drugs?
Ia: procainamide, quinidine
Ib: lidocaine
Ic: flecainide, propafenone (Rhythmol)
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
What are the common Class II drugs?
metoprolol, propranolol, esmolol, all the -lol’s
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
What are the common Class III drugs?
amiodarone, sotalol, dofetilide (Tikosyn), dronedarone (Multaq)
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
What are the common Class IV drugs?
diltiazem (Cardizem), verapamil
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
Which classes of antiarrhythmics can cause QT prolongation?
Ia, Ic, and III
They all delay repolarization… ST to T wave
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
T waves normally measure < _____ tall in limb leads, and < ____ tall in precordial leads.
6 mm
12 mm
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
Which leads NORMALLY have negative T waves?
AVR
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
What is the normal QTc?
< 0.42 sec
Which leads would show that a RBBB is present, and what would you see?
QRS > or = to 0.12
R,R’ in V1 and/or V2, slurred S wave in I & V6
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
If you see a Q,R’ in V1, this is indicative of…
…an old or new anteroseptal infarct in a patient with a RBBB. They need a heart cath!
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
Which leads would show that a LBBB is present, and what would they show?
QRS > or = to 0.12
Broad monomorphic R wave in I & V6 that are either both positive or both negative.
Broad monomorphic S wave in V1
May also see R, R’ in V5 or V6
[Powerpoint presentation by Dr. Miller, “Demystifying the 12 Lead EKG”]
