cardio Flashcards
cyanotic heart disease with no murmur
TGA and pulmonary atresia. May have single second heart sound.
av malformation
shunts blood to venous side, get b/l ventricular enlargement –> heart failure. Most common sites are liver and cerebrum (may have diminished pulses past carotid).
vein of galen aneurysm
persistent embryologic median prosencephalic vein of Markowski, which lies immediately anterior to the vein of
Galen, drains with help of persistent falcine sinus. Heart failure, hydrocephalus, ICH. Neuro symptoms from mass effect/bleed. High venous paO2 b/c doesn’t go through capillary bed.
cardiac embryology
mesoderm. tube formation –> looping –> septation. complete by 7-8w.
in utero ductal patency
pge2, prostacyclin (PGI2) and thromboxane 2
hypertension
can be secondary to renal artery thrombosis from uac, renal vein thrombosis from polycythemia, BPD.
tx: captopril (ace inhibitor), nifedipine (Ca channel blocker –> vasodilation), propranalol (b blocker)
qp:qs
large L –>R shunt if >2, large R –> L shunt if <0.7
wpw
delta wave, treat with b blocker (esmolol/propanolol). frequently seen in ebsteins
antiarythmics
Class Major Site of Action Example Class I Sodium channel Procainamide, lidocaine, flecainide Class II Beta adrenergic Esmolol (short acting), propranolol (long acting) Class III Potassium channel Amiodarone Class IV Calcium channel Verapamil -c/i in <1y, negative ionotropic effects Class I drugs change the upstroke, classes II and III drugs work on the sustained depolarization phase, and class IV drugs affect depolarization.
hypertrophic cardiomyopathy
treat with bblocker, decrease hr and contractility. less myocardial demand
dopamine
binds to a and ß adrenergic receptors, but with more peripheral a effect, raising PVR. This gives a higher blood pressure than dobutamine, dopamine often is started in septic shock to help increase PVR and stabilize the peripheral vascular derangements. Dopamine binds to receptors in the kidney and selectively reduces renal vascular resistance in premature infants.
dobutamine
a and ß adrenergic receptors; has inotropic and limited
chronotropic activity and also will lower peripheral vascular resistance (PVR). Coronary blood
flow and myocardial oxygen delivery improve
milrinone
inotropic drug that increases cAMP levels. works directly in the cell to inhibit the action of phosphodiesterase and
so prevent the hydrolysis of cAMP. dilating effect
on veins and arterioles, simultaneously can raise cardiac output and lower PVR, without increasing myocardial oxygen demand significantly.
cyanosis
if >3-5g/dL of reduced Hb
reverse differential cyanosis
IVS + TGA w/ phtn and pda, w/ interrupted aortic arch, w/ coarct
adrenal hemmorhage
may be asymptomatic. with large hemmorhage, may be persistently jaundiced, hypertensive, anemic. May see scrotal hematoma. Will see calcifications soon after.
truncus arteriosus
can present with early CHF because of systemic circulation pumping into pulmonary circulation. 1/3 assc w/ 22q11. VSD 98%. Bounding pulses, loud single S2, loud pansystolic murmur. Untreated, median survival 5 weeks.
term PDA
does not respond to pg inhibitors. can be due to first trimester rubella.
rhabomyoma
80% will have tuberous sclerosis complex. often asymptomatic in utero but can be assc with arhthymia. Assc with SVT and WPW. 80% regress spontaneously. Never enlarge postnatally. TS triad of MR, epilepsy, facial angiofibroma.
what are the most common benign cardiac tumors?
1) rhabdomyoma (60%)
2) teratoma - most in pericardial space
3) fibroma - most in IV septum
4) hemangioma
5) mesothelioma
when should congenital heart block due to SLE be treated
when heart rate is below 50, if patient is symptomatic
What is the ductus arteriosus derived from.
Sixth branchial arch.
What is the difference between indomethacin and ibuprofen on PDA closure?
Same efficacy. However, Ibuprofen is associated with decreased impact on renal function. Indomethacin also associated with a reduction of IVH.
What are the two most common cardiac lesions in turners syndrome?
1) bicuspid aortic valve (~50%) and 2) coarctation of the aorta (~10%)
how does furosemide impact the ductus?
it stimulates PGE2 synthesis in the ascending loop of henle, causing the ductus to remain open
what is the norwood procedure vs hybrid
it is the first in a three step procedure to repair HLHS.
1) atrial septostomy
2) neo aorta using PA, connected to RV
3) PA to RV shunt (BT shunt)
The hybrid is for patients who are much sicker and can’t handle cardiac bypass. Via cath, the PDA is stented and the PAs are banded, and there is intra atrial baloon septostomy.
what are the three steps in HLHS repair and about when do they happen?
1) norwood or hybrid, within 1st month
2) SVC to PA and removal of PA/RV shunt, around 4 mon
3) IVC to PA –> this is the step when baby is no longer cyanotic, around 4 y/o
what are the different kinds of AV block and most common causes
1: prolonged PR interval, normal is 0.14-0.16 seconds
2-I: progressively prolonging with dropped qrs
2-II: prolonged PR with ever x# dropped (ie. 2:1)
3: complete av block, complete dissociation
2 and 3 may need pacing
most common causes: maternal lupus, digoxin, adenosine
what is the formula for corrected qtc
qtc - qt/square root of r to r interval. Normal qtc is 400-440ms
what are causes of prolonged qtc
hypocalcemia, hypokalemia
what medication do you not want to use in WPW
digoxin
what is WPW
WPW is a condition predisposed to AVRT, producing conduction through both the AV node and an accessory pathway, causing pre-excitation delta wave. Associated with SVT. Do not treat with dig.
What are the three most common kinds of SVT
1) AVRT (accessory pathway), assc with WPW
2) AVNRT (nodal pathway)
1+2 associated with each p has a narrow qrs (
How do you treat a flutter
cardiovert. P waves will not all have qrs wave b/c av node slows down ventricular rate. Unlikely to recur. Looks like saw tooth. Associated with cocaine, opiate, or complex congenital heart disease.
what are the 5 different kinds of shock
1) MC: hypovolemic, usually due to sepsis.
2) cardiogenic: poor heart function due to hypoxia, sepsis, cardiomyopathy, arrythmia –> CHF. Tx: Decrease SVR, avoid volume
3) distributive: “warm shock” usually due to sepsis, excessive vasodilators, adrenal insufficiency. Presents with widened pulse pressures, bounding pulses. Tx: increase SVR.
4) Flow restrictive: tamponade, tension pneumo. Presents as CHF.
5) dissociate - least common, due to profound anemia, CO, methemoglobinemia, poor release of O2 to tissue
which rhythyms do you defibrillate (unsynchronized cardioversion)
Vfib, pulseless vtach, polymorphic vtach. Use 1-2 J/K (more than when synchronized)
which rhythyms do you synchronized cardiovert
SVT, monomorphic vtach, aflutter (less than when unsynchronized) 0.5-1J/k
what is the primary issue with TOF with absent PV?
lots of regurg from branch PAs –> get very dilated and can obstruct airway. place prone, may need to intubate.
what medication do you use for a flutter
digoxin to block the ventricular rate
if unstable –> cardiovert
doesn’t usually recur
when does septation (fusing of endocardial cushions) of the heart happen
between 7-8th week
what are the most common cardiac lesions with digeorge
TEF, interrupted arch, truncus
“george climbs up the interrupted trunk with all four limbs”
digeorge (22q11) is secondary to impaired development of what structure?
3rd and 4th pharyngeal arches
when is a pulmonary hemmorhage secondary to a PDA most likely?
first 3 days of life
what does the a1 receptor do?
increase SVR and increase inotropy (contractility)
which cardiac lesion are HAND and NOTCH mutations associated with? Also GJA1 and NKX25
HLHS
which two EKG findings is Ebstein anomaly assc with?
RBBB (75%) and Delta wave/WPW (60%)
what gene is most commonly effected in long QT syndrome?
KCNQ1
which cardiac lesions are common in DM?
VSD, TA, DORV
What is an abnormal ekg finding in a neonate?
Tall peaked P waves, indicates atrial enlargement.
Normal:
R axis deviation, upright T waves in V1 (r v strain), low voltage wrap and t waves
What are characteristics of hypertrophic cardiomyopathy?
Usually secondary to genetic defect in myosin chain.
In IDM, transient, usually of IVS. Supportive care. Inotropes May worsen obstruction.
how does vasopressin act?
minimal chonotropic effect.
how do beta blockers act?
prevent chonotropy
what is treatment for fetal SVT?
primary treatment is maternal dig. if hydropic, flecanide or sotolol
what genetic syndrome associations are there with HLHS?
Tri 13, 18, turner, hold-oram, jacobsen
Right sided aortic arch noted 25% of time in which cardiac lesion?
TOF
why is the heart so enlarged in Ebsteins?
due to RA enlargement from massive tricuspid regurg
most common cause of neonatal hypertension? how does it present?
renovascular (90%), usually due to UACs. May cause microthrombi in kidneys causing infarctions.
can present with CHF, poor perfusion, htn encephalopathy
how do ace inhibitors work
block ACE ( angiotensin i doesn’t become angiotensin II)
which cardiac lesions need immediate surgery?
HLHS with IAS
obstructed TAPVR
what is post ligation cardiac syndrome
w/i 24 hours post/op of surgically repairing PDA, LV preload is decreased resulting in hypotension while starling point resets. tx: increase SVR
what is shone syndrome
heterogenous group of left sided cardiac lesions
what are adverse effects of amiodarone
amiodarone –> hypothyroidism
when do you use adenosine
conversion of AVRT
when do you use digoxin
ectopic atrial tachycardia, SVT w/o WPW
when do you use proponalol
first line for long term SVT with WPW
- may exacerbate reactive airway disease
