EP Flashcards
congenital 2:1 block
LQT syndrome
what is the u wave from
repol of purkinje fibers
mortality if 2:1 block as a fetus
50% at 6 months, 2/3 by 2 years
gene of LQT1
KNCQ1 (Potasium K channel)
gene LQT2
KNCQ2 (potassium K channel)
gene LQT3
SCN5A (Na channel) Sodium ChaNel
elecrolytes that prolong QT
hypoKalemia, hypo Mg, hypo Ca
T waves for LQT1,2,3
1 broad, 2 broad with notch, 3 long isoelectric (shark fin)
Inverted T waves in V1-V3 at > 14 years old
ARVC (right heart)
EKG for ARVC
inverted T wave V1-V3 if > 14 years (right heart)
Upright T wave in V1 or V3R between 3 days and 8 years
high spec for RVH
qR pattern in right sided precordial leads (V1, V3R, V4R)
severe RVH
pure R wave/RR’ in right sided precordial leads (V1, V3R, V4R)
=> RV pressure overload
Q waves > 3 mm and tall symmetric T waves in V5 or V6
LV volume overload (PDA) or septal hypertrophy
Which leads in ALCAPA
q wwaves Lateral leads, also watch for ST changes and abnormal R wave progression
first line fetal SVT if no hydrops, dose target?
digoxin, maternL > 2 (0.6 transfer rate, hydrops decreased by 50%)
fetal SVT drugs if hydroptic
sotalol or felcainide
risk of sudden cardiac death in LQTS
1) QTc>500 2) previous episode of syncope
infantile atrial flutter, Tx and Px?
Tx: DC cardioversion Px: good, low risk recurrence
strongest predictors of risk of SCD in HCM
1)fam Hx sudden death 2) septal thickness >30mm
secondary predictors: NSVT, syncope, BP blunting with exercise
amiodarone drug drug interactions?
inc warfarin effect, digoxin + phenytoin levels, class I antiarrythmic toxicity
borrelia burgdorferi
lyme disease, central clearing = erythma migrans: treat with doxy or ceftiaxone
sports EKG with T wave inversions, which are normal abnormal, what do you do?
normal V1, abnormal V5,V6, get an echo
opthalmoplegia + heart block, what is it?
Kearns-Sayre syndrome. (mitochondrial defect with ataxia, eye muscle stuff, vision problems, heart block), implant a pacemaker if bifascicular block. [Corn Slayer - corn is for eyebals, slayer is for slicing the conduction system]
bad prognosis LQTS in a newborn
LQTS with 2:1 block -> 50% mortality
what does lack of HR variability in a fetal indicate?
fetal hypoxemia -> CNS depression -> loss of fetal HR variability
why is the T wave in V1 positive at birth?
early repol of the LV and late termination of depolarization from the RV
wat causes PJRT?
slow accesory pathwya in the right posterior septum
slow -> P wave visable (negative in II, III, aVF, due to location), slower rate (150-200)
what CHD is associated with CHB?
ccTGA, LAI, DORV, AVSD: poor prognosis 30% 1 yr survival
1st child had autoimmune fetal CHB, what is risk for child 2?
11-19%
risk of CHB if SSA> 50?
1-5% (second child 11-19%)
medication contraindicated in WPW?
verapamil
intracardiac tracing where most activity falls under the QRS?
typical AVNRT
tachycardia that is wide and irregular
a fib with WPW
when is adenosine contraindicated?
wide irregular tachycardia = a fib with WPW
how does pacemaker mediated tachycardia work?
V pace, retrograde through AV node, atrial activation, “p” wave sensed and V is paced
intracardiac, stim of atrium: what do you check?
conduction to V, then check HV interval if negative WPW
intracardiac, stim of ventricle: what do you check?
conduction to A, midline or eccentric
intracardiac, no stim, next question
fast or slow
intracardiac, no stim, slow, what to look for
earliest A
intracardiac, no stim, fast, 3 questions
narrow/wide, reg/irregular, A/V relationship
intracardiac, no stim, fast, more As than Vs
A fib or A flutter
intracardiac, no stim, fast, more Vs than As
junctional or VT: junctional shows a his deflection before the QRS, VT may have dissociated As and Vs
intracardiac, no stim, fast, #As = #Vs, what to look for?
look for earliest A
