basics Flashcards
wandering pacemakers do what tho the PR interval
cause it to vary
sinus dysrhythmia and second degree heart block are_____ irregular
patterned
P wave duration longer than 10 seconds suggests ___ and is called ____
LAE and is called P mitrale
what is the QT interval good for measuring
ventricular depolarization and repolarization
which are the unipolar leads
aVR, aVL, aVF, and V1- V6
R wave represents
impulse going through bundle branches and into the purkinje fibers
what does V2 view
RV
in the QRS complex, which waves can there be more of
R and S (R’ or r’ or S’ or s’)
what does a normal PR interval length
0.12 to 0.2 seconds (3-5 small boxes)
paroxysmal tachycardia is …
a normal HR that suddenly accelerates to a rapid rate produces an irregularity
what is the j point
where the QRS complex meets the ST segment (the exact point where it hits the isoelectric line)
what is aberrant conduction
when the next impulse reaches the bundle branch while it is still in the refractory period
lead 1, aVL, and V5-V6 abnormalities suggests
ischemia/ infarct to the lateral region of the heart
what can cause a shorter PR interval (less than 0.12 seconds)
when a supraventricular impulse travels through weird accessory pathways to get to the ventricles, leading to premature ventricular depolarization (pre-excitation)
what does the aVF view
inferior wall of LV
what can cause low voltage QRS complexes
obesity, pericardial effusion, hypothyroidism
V1-V4 abnormalities suggests
ischemia/ infarct to the anterior region of the heart
what causes widened bizarre QRS complexes
intraventricular conduction defect; often a bundle branch block
atrial flutter, a-fib, 3rd degree AV heart block, and ventricular dysrhythmias do what to the PR interval
make it absent
the bigger the dipole ….
the bigger the deflection in the direction of the electrode
what does V4 view
septum
which leads are enhanced by the EKG machine
augmented leads (because they’re usually so small)
what does more P waves than QRS complexes indicate
the impulse was initiated supraventricularly but was blocked and could not reach the ventricles
widespread abnormalities across the EKG suggests
a drug or electrolyte effect
what does the V1 view
RV
normal duration of the QT interval
0.36 to 0.44 seconds (9 to 11 small boxes
the P wave represents
atrial depolarization
S wave represents
impulse moving back up the heart wall, away from the apex; heads back towards lead 2
which wave should you always have
T
leads 1, aVL, V5, and V6 are associated with what aspect of the heart and what artery
lateral aspect (LV) and left circumflex artery
what does V3 view
septum
why is repolarization positive
(like a double negative) it is moving back towards the origin of lead 2 (so would normally be negative), but it is in the direction of a negative (not positive) charge
a 2nd degree AV heart block does what to the PR interval
cause it to vary (gets progressively longer until 1 complex is dropped, then starts again)
___ waves are produced when the atria rapidly fires at a rate of 250-350 bpm
flutter (F)
Q wave represents
impulse slowly going outward through myocytes intraventricular septum
the QRS complex represents
ventricular depolarization
what can cause tall QRS complexes
hypertrophy of 1 or both ventricles, an abnormal pacemaker, an aberrantly conducted beat
what is the normal duration of the QRS
0.06 to 0.12 seconds (1.5 to 3 small boxes)
on ECG paper, 1 small box vertically =
1 mm or 0.5mV
if the pt has atrial tachycardia and the T waves are peaked, notched, and large, what should you think
that the P wave is hidden in the T wave
what does a normal P wave look like
0.06 to 0.1 seconds (1.5 to 2.5 small boxes), 0.5 to 2.5 mm (1 to 5 small boxes), upright and round
a wandering atrial pacemaker is ____ irregular
slightly
what what does the PR segment correlate with
impulse traveling through the AV node
leads 2, 3, and aVF abnormalities suggests
ischemia/ infarct to the inferior region of the heart
on ECG paper, 1 small box horizontally =
0.04 seconds
a 1st degree AV heart block does what to the PR interval
lengthens it
what does the aVR view
base of the heart (atria and great vessels)
a-fib is ____ irregular
totally irregular aka irregularly irregular
leads V1- V4 are associated with what aspect of the heart and what artery
anterior aspect and the left anterior descending artery (widow maker!)
P wave amplitude greater than 2.5 mm suggests ___ and is called ___
RAE and is called P pulmonale
a positive deflection indicates the impulse is moving ____ the lead vector, while a negative deflection indicates the impulse is moving ____ the lead vector
a positive deflection indicates the impulse is moving TOWARDS the lead vector, while a negative deflection indicates the impulse is moving AWAY the lead vector
the T wave represents
ventricular repolarization
PACs, wandering atrial pacemaker, and atrial tachycardia all have P wave impulses ___
that arise from the atria but NOT the SA node
atrial repolarization is where?
hidden in the QRS wave
___ waves are produced when the atria rapidly fires (from many sites) at a rate of MORE than 350 bpm
fibrillatory (f)
leads 2, 3, and aVF are associated with what aspect of the heart and what artery
inferior aspect (RV) and right coronary artery
which are the bipolar leads
limb leads 1, 2, 3
as the HR slows, QT interval ___
increases
what does the aVL view
lateral wall of LV
