Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
62 Cards in this Set
- Front
- Back
|
If a pts rhythm strip shows the R waves are 4 large boxes between complexes, what is the heart rate?
|
75
(300, 150, 100, 75, 60, 50...) |
|
|
The rhythm strip on the bottom of a EKG is how long?
|
12 sec
(3 sec each lead on other leads) |
|
|
What is the rate range for normal sinus rhythm?
|
60-100
|
|
|
Define sinus bradycardia.
|
Heart rate less than 60, regular, with beats having P-QRS-T
|
|
|
What is the rate range for ventricular focus induced rhythms?
|
20-40 beats per minute
|
|
|
The malfunction of what organ system is the usual cause of multifocal atrial tachycardia?
|
pulmonary
|
|
|
The difference between multifocal atrial tachycardia and wandering atrial pacemaker is decided by:
|
WAP rate 100
MAP rate greater 100 |
|
|
What is the maximal normal QRS width?
|
0.12
normal 0.06-0.11 |
|
|
Which atrial dysrhythmia usually occurs between an atrial rate of 250-350?
|
Flutter 250-350
Firbrillation 350-450 |
|
|
In atrial fltutter, what is the most common form of AV block?
|
AV node block (usually 2:1)
|
|
|
Whick of the irregularly irregular rhythms is due to many causes and is the most common to occur?
|
atrial fibrillation
|
|
|
What electrical finding on the EKG signifies pacer induced rhythm?
|
electrical spike that is too narrow to be physiologically normal
|
|
|
What signs help separate ventricular tachycardia from supraventricular with bundle branch block?
|
Brugada's sign: Vtach
|
|
|
What signifies first degree heart block?
|
PR greater than 0.2 sec
|
|
|
What signifies that the second degree block is Mobitz 1?
|
progressive lengthing of the PR intervals until a ventricular beat is dropped (**99+% of the time)
|
|
|
Describe the atrial and ventricular rates in third degree AV block.
|
atrial rate:
ventricular rate: 20-40 |
|
|
What happens to the timing of the following beat, post PVC?
|
compensatory pause
(PACs do not have a compensatory pause) |
|
|
In what leads do you expect the P waves to always be positive?
|
+ P in leads 1, 2, V4-6
(-P in lead aVR) |
|
|
What is the difference between WPW pattern WPW syndrome?
|
WPW Pattern
short PR interval wide QRS delta wave ST-T wave changes WPW Syndrom: all above + proxysmal tachycardia |
|
|
How does the PR interval change in Wenkebach block versus Mobitz 2?
|
Wenkebach (Mobitz 1) AV node has long refractory period- progressive legnthing until dropped QRS
Mobitz 2 (more dangerous) PR intervals constant until sudden dropped beat |
|
|
Define complete heart block.
|
complete dissociation of Ps and QRSs
always more Ps than QRSs |
|
|
Define a Q wave.
|
first negative deflection after the P wave
|
|
|
Define a significant Q wave.
|
0.03 sec or wider
depth equal to or greater than 1/3 R wave |
|
|
What do Q waves in two or more adjacent leads mean?
|
MI
(need ST changes to dx ACUTE MI) |
|
|
What is the normal QRS duration?
|
0.06-0.11
|
|
|
In which leads does one expect the usual transition zone to occur?
|
transition zone= where precordial leads change from neg to pos.
usually between V3 and V4 |
|
|
Extremely low voltage of every wave in every lead could indicate which 2 possible conditions?
|
MI (scar tissue is electrically inert)
marked increase body fat huge pleural EFFUSION pericardial EFFUSION recording at half standard |
|
|
What condition precludes the diagnosis of left ventricular hypertophy?
|
LBBB
only dx with normal QRS morphology |
|
|
What conditions can cause a QRS duration of great than .11 sec width?
|
LBBB
RBBB IV conduction delay (don't look like LBBB or RBBB) WPW |
|
|
What metabloic emergency can cause IVCD?
|
hyperkalemia
|
|
|
How wide does the QRS have to be before you can diagnose at bundle branch block?
|
at least one lead with QRS > 0.12
|
|
|
If the axis of an EKG is "normal," which 2 EKG leads would be expected to be positive?
|
lead 1 and aVF
|
|
|
Which bundle by definition is always involved in bifascular blocks?
|
RBBB
(+ one of the hemi's) |
|
|
What diagnosis can never be made in the presence of a Left Bundle Branck Block?
|
LVH
(left ventricular hypertrophy) |
|
|
What is the typical QRS appearance in RBBB?
|
RSR`
"rabbit ears" |
|
|
What is the typical QRS appearance in LBBB?
|
discordant T waves (opposite direction)
small R in V1 "uglygram" |
|
|
What axis would you expect with a left anterior hemiblock?
|
vector is superior an leftward
axis: -30 to -90 deg lead 1: qR or R lead 3: rS |
|
|
In determining the vector of the ORS, what is the characteristic of the isoelelctric lead even if R wave size is a different amplitude than the S wave?
|
the axis is +/- 20deg from the axis of the isoelectric lead
|
|
|
What is the hallmark of acute transmural MI?
|
pathologic Q wave (wider than 0.03, or greater than 1/3 depth of R wave)
|
|
|
What is the hallmark sign of acute ischemia?
|
ST depression and T wave opposite to QRS
|
|
|
What is the EKG clue for Arythmogenic Right Ventricular Cardiomyopathy?
|
R ventricular inherited desmosome problem= SUDDEN DEATH
epsilon wave-small waves at the J point |
|
|
What is the QTC?
|
QT interval corrected for heart rate
QTC = QT + 1.75X normal up to 0.419sec |
|
|
In a normal EKG what can be stated about the T and U waves?
|
normal: T and U always in same direction
bad (ischemia til proven otherwise): T and U opposite |
|
|
Why do normal T waves occur in the same direction as the QRS?
|
Perkinje system is endocardial-> depolarization is endo- to epi-. Repolarization is opposite because ap duration is longest in the epicardium. Depolarization going toward electrode and repolarization going away from electrode both are positive!
|
|
|
T wave shape should always be:
|
asymetrical
|
|
|
What causes should you consider in significant T wave elevation?
|
acute MI
hyperkalemia (greater than 6mm in limb leads or 12 mm in precordial) (T 2/3 height of the R) |
|
|
what is the difference on EKG between LVH and LVH with strain?
|
LVH with Strain- asymmetrical ST depression
|
|
|
What ST changes are expected in an EKG of a patient with pericarditis?
|
PR depression
diffuse ST changes without reciprocal ST depression scooping- upward slope of ST Notching at end of QRS |
|
|
What is the relationship of the T wave to the QRS in a Bundle Branck Block?
|
LBBB- discordant T waves (opposite QRS
|
|
|
What is meant by the term "reciprocal changes" in an EKG and in what pathological state is it relevant?
|
lead opposite the damaged area show opposite changes.
ST elevation in one side, ST depression in the opposite |
|
|
Which ion essentially sets the non-pacemaker myocytes resting membrane potential?
|
potassium
|
|
|
What happens to the cell membrane electrically to cause an action potential?
|
influx of Na+
|
|
|
What is differnct about phase 4 action potentials in pacemaker cells and what ion and channel is chiefly responsible?
|
Na+ and Ca++ leak channels allow electrical potential to slowly increase during phase 4
|
|
|
What is the name for the potential difference across the membrane reqquired to maintain the concentraiton gradient?
|
equilibrium potential
|
|
|
What phase of the action potential is responsible for repolarization and what ion is most responsible?
|
phase 1
transient K channel (K+) also Ca++ entering thru slow Ca++, fast Na+ channels are inactivated |
|
|
Which ion is predominantly responsible for the plateau phase of an action potential?
|
phase 2
slow Ca++ chanels stay open- creates electroneutrality |
|
|
What phase/s of the action potential found in myocardial muscle cells is missing from pacemaker cells?
|
NOT phase 1 and 2
Pacemaker cell phases: 0, 3, 4 |
|
|
What is the funciton of the fast Na+ channel in phase 0 of pacemaker cells?
|
depolarization
|
|
|
What two mechanisms are responsible for Phase 0 in pacemaker cells?
|
L type Ca++ channels
funny Na channel (If) |
|
|
What EKG abnormality would you expect to demonstrate with severe aortic stenosis?
|
LVH or LBBB
|
|
|
What EKG abnormality would be most likely in severe mitral stenosis?
|
A-fib or P mitrale (P>0.12 and notched)
|
|
|
What EKG abnormalities would you expect in severe chronic mitral regurgitation?
|
P mitrale (P>0.12 and notched)
|
