EKG Flashcards
Normal QRS axis
-30 and +100
PR interval
120-200 ms (3-5 small boxes)
QRS interval
<80 ms (2 small boxes or less)
QT interval
<1/2 R-R interval
QTC
QT int/sq rt(R-R)
~400 ms
PR interval boundaries
from start of P to start of Q
narrow PR
pre-excitation
Prolonged PR
more than one big box
LVH
inc QRS amp
amp of S-wave (v1) + R-wave (V5. V6) >35mm (7 big boxes) OR amp of R-wave in aVL >11mm OR amp of R-wave in l>15mm
Inc QRS
LVH
(systemic HTN
AV stenosis
HCM)
dynamic ST elevation
acute MI
pericarditis
stable ST elevation
LV aneurysm, LBBB
sudden ST depression
sudden myocardium ischemia
chronic ST depression
LVH
anterior STEMI
leads
I
aVL
V2-V4
inferior STEMI
leads
II
III
aVF
T wave inversion
recent bout of myocardial ischemia
first degree AV block
PR int > 200 ms
progressive inc PR then non-conducted
second degree AV block
Mobitz I AV block
Wenkebach
fixed PR then non-conducted
second degree AV block
Mobitz II
regular R-R intervals
varying P waves
narrow QRS
third degree AV block
complete block
w/ AV escape
regular R-R intervals
varying P waves
wide QRS
third degree AV block
complete block
w/ ventricle escape (UNSTABLE)
QRS >120 ms
sinus or supra ventricular rhythm
RBBB or LBBB
QRS >120 ms
sinus or supra ventricular rhythm
RsR’ (V1-2)
RBBB
rabbit ears
QRS >120 ms
sinus or supra ventricular rhythm
negative wave in V1
LBBB
preceded by P-wave
usu narrow QRS
may not conduct to ventricle
resets SA
supraventricular PAC
no p-wave
wide QRS
may not conduct to atrium
usu no effect on SA
ventricular PVC
bigeminy
alternating normal beat and premature beat
irregularly irregular
A-fib
saw-tooth
atrial flutter
saw tooth=p’s
AV reciprocating Tacyhcardia
Wolff-Parkinson-White Syndrome
“Bypass tract”: connecting atria to ventricle
“preexcitation” of ventricle by bypass track (in addition to activation by AV node pathway)
____ tachyarrhythmias are responsive to electrical cardioversion
ventricular
monomorphic VT
wide complex tachycardia, similar QRS
wide bc VT lacks coordinate electrical activities of ventricles
reentry arrhythmia from one area of ventricle (often prior myovcardial infection scar)
polymorphic VT
wide complex tachycardia, variable QRS
acute ischemia, meds that prolong QT
can progress to Vfib
TORSADES DE POINTES
drugs, dec K/Mg, congenital abnml
Tx: Mg sulfate
SVT w/ aberrancy
can have wide QRS if BBB
AV association (P before QRS)
wide QRS (>120ms) can be
V tach (monomorphic or polymorphic)
or
supraventricular w/ BBB
first degree AV block tx
benign, no tx needed
lyme disease
AV blocks
P waves and QRS complex dissociation
atria rate>ventricle rate
complete AV block
delta wave
short PR
WPW
wide complex
irregular
tachycardic
a fib in WPW
torsade de pointes
ventricular tachycardia w/ prolonged QT
triggered by a PVC at this time
muscle weakness
U waves
hypOkalemia
hypERkalemia
peaked T waves
peaked T waves
hypERkalemia
confusion
vol depletion
short QT
hypERcalcemia
muscle spasms
tetany
prolonged QT
hypOcalcemia
if sinus pause >3 sec
pacemaker
no med therapy options
acute MI EKG
ST elevation
hrs after STEMI EKG
ST elevation
dec R wave
Q wave begins
days 1-2 post MI EKG
T wave inversion
Q wave deeper
days after MI
ST normalizes
T wave inverted
weeks after MI
ST and T normal
Q wave persists
circumnavigating tricuspid valve annulus
a flutter
paroxysmal supraventricular tachycardia
- regular tachycardia (typically narrow QRS complex)
- sudden onset/offset
- P waves may be hidden in the QRS complex or buried in ST segment
- AVNRT
- AVRT
AVNRT
- reentrant arrhythmia contained within the AV node
- fast path (slow repolarization)
- slow path (fast repolarization)
- wave arrives at AV node while fast path has not yet depolarized, so wave travels down slow but then reenters fast and goes up.
- activation of ventricles and atria each time process repeats
terminates via block of AV node (vagal maneuvers or adenosine)
AVRT
- caused by “bypass tract” connecting atria to ventricle (WPW)
- “preexcitation” of ventricle
- accessory path of myocardial fibers exists that traverses the AV groove acting as a parallel conduction system
- usu ORTHODROMIC (narrow QRS) —-> impulses go down AV and depolarize ventricle, then return to atrium retrograde via bypass tract (impulse going ventricle –> atria) and activating atrium. AV node activate and process repeats.
- rarely antegrade (antidromic)
- NO decremental conduction properties characteristic of the AV node –> shortened PR
most feared complication of WPW
a fib
