37. Electrophys Flashcards
intraop 5 lead
II
V5
intraop 5 lead covers
80% of ischemic changes
lead II
MEA
RV
inf LV
V5
lateral LV
polarized state is mx by
Na+/K+ atpase
what propagates AP through myocardium
Na+/Ca2+ channels
what is involved with excitiation/contraction coupling
Ca2+
what is involved with myosin power stroke
Ca2+
right heard leads
V1
V2
interventricular septum leads
V3
V4
left heart leads
V5
V6
inotropy
speed and strength of cardiac contraction
lusitropy
relaxation and ventricular filling
issue with inotropy causes
systolic heart failure
issue with lusitropy causes
diastolic heart failure
1st degree AV block: cause
athlete
digoxin
B blocker
CCB
ischemia
MD
1st degree AV block: avoid
vagal stimulation
electrolyte abnormalities
ischemia
1st degree AV block
2nd degree AV block type 1
2nd degree AV block type 2
3rd degree AV block
adams-stoke attack
sudden fainting spells due to drop in CO
(3rd degree block)
RBBB ecg
wide QRS > 120 ms in leads 1/2
deep S in leads 1/V6
RBBB
Left BBB Ecg
wide QRS > 120 ms
no Q wave in 1, V5, V6
broad/notched R wave in 1, aVL, V5, V6
LBBB indicates
ischemic serious heart disease
lab for ischemia
troponin C
LBBB
tachydysrhythmia with narrow QRS
ABOVE BOH:
sinus tach
a fib
a flutter
junctional tach
paroxysmal atrial tach
accessory pathway rachycardia
wide complex tachycardia
BELOW BOH:
V TACH
SVT w/intraventricular defect
SVT w/aberrant conduction
SVT w/preexcitation pathway
arrythmia initiation mechanism
- incr automaticity
- reentry through abnormal pathway
- trigger of potential after depolarization
what can induce automaticity
any myocyte
what sets the normal value
the inerrant baseline automaticity
what decreases timeframe for depolarization
phase 4 shift
sinus tachycardia
PAC
paroxysmal SVT
orthodromic
more common
narrow QRS
no delta
antidromic
less common
wide QRS
delta wave
orthodromic AVRT conduction
antegrade conduction through AV node
antidromic AVRT conduction
retrograde conduction through AV node
WPW antidromic
WPW orthodromic
afib
afib w/RVR
afib w/RVR criteria
- afib rhythm
- HR > 100bpm
aflutter
PVC bigeminy
PVC trigeminy
Nonsustained ventricular tachycardia
(grouping of PVCs)
R on T phenomenon
PVC that occurs during middle 3rd of relative refractory period of T wave
long QT males
QT> 440ms
long QT females
QT>460 ms
most common inherited form of long QT
romano-ward syndrome
increased risk of polymorphic VTACH
QT>500ms
treat prolonged QT
mg
K
discontinue QT prolongation drugs
pacing (if neede)
which is worse: SVT or NSVT
NSVT
monomorphic VTACH
polymorphic VTACH
Vfib
sinus brady
junctional pacing comes from
AV node
junction HR
40-60 bpm
junctional bradycardia
junctional tachycardia
adenosine indication
AVNRT
AVRT
adenosine CI
SSS
3rd degree AV block without pacer
adenosine antagonist
caffeine
theophylline
adenosine dosing
6mg
12mg
12mg
atropine indication
symptomatic bradycardia
atropine dose
0.5mg IV
amiodarone mechanism
K+ channel antagonist
amiodarone dosing
PVT/Vfib: 300 mg initial/150 redose
others: 150 mg
beta blocker mechanism
antagonize beta receptors
slow AVN conduction
beta blocker CI
2nd degree heart block
3rd degree heart block
severe CHF
RAD
WPW
CCB indication
narrow complex QRS tachycardia
afib/aflutter
SVT
CCB CI
WPW
beta blockers (causes heart block)
CCB dosing
verapamil: 2.5-5mg IV (0.15 mg/kg)
diltiazem: 0.25 mg/kg IV
digoxin mechanism
Na/K ATP antagonist
digoxin dosing
400-600 mg total
dopamine indication
2nd line treatment for symptomatic brady
dopamine dosing: incr blood flow
3-5mcg/kg/min
dopamine dosing: b agonist
5-7mcg/kg/min
dopamine dosing: a agonist
> 10mcg/kg/min
epi mechanism
adrenergic agonist
when will you need higher doses of epi
if pt is on beta blocker or CCB
isoproterenol mechanism
B1 and B2 agnoist
isoproterenol dose
2-10mcg/min
lidocaine mechanism
Na+ channel antagnoist
lidocaine dosing
1-1.5 mg/kg (up to 3 mg/kg total)
mg dosing: pulseless
1-2g over 5 mins
mg dosing: pulse
1-2 g over longer period
mg mechanism
cofactor that aids Na/K transport
procainamide mechanism
Na+ channel antagonist
procainamide dosing
50mcg/min