2/22 Flashcards
Congenital long QT syndromes
-problem w/what?
-disorder of myocardial repolarization, typically due to ion channel defects.
QT interval
- mechanical contraction of ventricles.
- QRS wave til end of T wave (repol).
- long QT interval predisposes to Torsades
Romano-Ward syndrome
- congenital long QT
- auto dom.
- pure cardiac phenotype, no deafness
Jervell and Lange Neilson syndrome
- congenital long QT
- auto recessive
- sensorineural deafness
What is neg. feedback on renin?
- angio2, aldo.
- you can also have low renin (not just by neg feedback) but by high renal perfusion and low Cl- at the macula densa!)
What is the most common side effect of epleronone and spironolactone?
- gynecomastia.
- more so w/spironolactone
What causes type 4 renal tubular acidosis
-hypoaldosteronism.
1-Familial hyperchylomicronemia
- protein defect?
- whats happening?
- major manifestations?
- LPL or apoC2
- TGs can’t be broken down and taken out of chylos & VLDL.
- acute pancreatitis, eruptive skin xanthomas, hepatosplenomegaly.
- lipemia retinalis = milky appearing retinal vasculature
2a-familial hypercholesterolemia
- protein defect?
- whats happening?
- major manifestations?
- LDL receptor, apoB100
- LDL = full of cholesterol, gets trapped in blood cuz can’t be taken up by liver.
- premature CAD, corneal arcus, tendon xanthomas, xanthelasmas.
- xanthoma of achilles tendon
4-hypertriglyceridemia
- problem?
- manifestation?
- hepatic overprod. of VLDL.
- pancreatitis
Ligand for LDL receptor?
apoB-100
familial hyperchylomicronemia
-are they are risk for premature CAD?
- no
- their LDL and HDL levels are fine.
- CAD risk main indicator is HDL levels.
What types of drugs have a low volume of distribution?
- large/charged molecules
- plasma protein bound
Whats the average total body water?
41 liters
- plasma volume = 3 L
- interstitial = 11 L
- so about 14 L out of 41 L is extracellular fluid.
Lichtenburg figures
-fern-leaf pattern cutaneous marks following a lightning strike. lol.
U wave
- what is it?
- what can it point to?
- electrical activity of papillary muscles.
- hypokalemia, bradycardia
midline of EKG
- cells are depolarized
- no more current flowing
which interval = systole?
QT interval
-so vent repolarization is also part of systole.
Which drugs can slow down AV node? and how?
-can prevent atrial tachys from getting to ventricles.
- Ca channel blockers: slow phase 0 of AV node.
- beta blockers: blocking beta-1
- digialis: inc. vagal activity, inhibition conduction thru AV node.
Heart block
-which segment is elongated?
- AV nodal block aka junctional block.
- PR segment
2nd deg. heart block: Mobitz 1
*Wenckebach
Progressive elongation of PR interval until one P wave not followed by QRS, then cycle repeats.
*usually asymptomatic.
2nd deg. heart block: Mobitz 2
PR interval is stable, but at some point, a P wave is not followed by QRS.
- often found as 2:1 Heart Block
- often treated w/pacemaker
Causes of torsades de pointe
-treatment?
- drugs, dec. K, dec. Mg
- Tx: magnesium sulfate
Drugs that can cause torsades
Sotalol, Risperidone (antipsychotics), Macrolides Chloroquine, Protease inhibitors (-navir), Quinidine (class Ia; also class III), Thiazides *Some Risky Meds Can Prolong QT
Afib: describe tracing
-irregularly irregular
-no discrete P waves (atrial depol)
-
Atrial flutter: describe tracing
- A rapid succession of identical, back-to-back atrial depolarization waves.
- Sawtooth appearance.
Vfib: describe tracing
-no identifiable waves
3rd degree heart block (complete)
-what infection can result in this?
- no AV conduction. atria and ventricles independent of each other.
- atria are faster than ventricles.
- lyme diseaes can lead to complete heart block.
B-type (brain) natriuretic peptide
-where is it released from?
- Released from ventricular myocytes in response to inc. tension.
- longer half life than ANP.
- good negative predictive value for diagnosing heart failure.
recombinant form of BNP?
neseritide
aortic arch baroreceptor
-what does it respond to?
- only respond to increases in BP.
- inc. in BP = inc. firing of vagus to solitary nucleus = increased inhibition of sympathetics.
carotid sinus baroreceptor
-what does it respond to?
-responds to both increases and decreases in BP.
Cushing reaction triad
-increased BP, resp. depression, and dec. heart rate.
Periph. chemoreceptors
-stimulated by what?
- dec. pH
- inc. pCO2
- dec. pO2
- so only stimulated when you need to breath more.
Which organ extracts the most O2 from its blood supply?
- Heart. Extracts ~80% O2 from its blood source.
- so inc. O2 demand met by inc. coronary blood flow, not by extracting more O2.
Heart: local vasodilatory metabolites?
- adenosine
- CO2
- NO
Skeletal muscle: local vasodilatory metabolites?
- lactate
- H
- K
- adenosine
- CO2
Filtration constant Kf
-determined by what?
capillary permeability
Jv = ?
Jv = net fluid flow Jv = Kf*Pnet
Whats one disease that inc. oncotic pressure of interstitum?
lymphatic blockage
What are the 5 right-left congenital cardiac shunts?
1-truncus artiosus 2-transposition of great vessels 3-tricuspid atresia 4-tetralogy of fallot 5-total anomalous pulm. venous return
Cause of truncus arteriosus?
Abnormal neural crest cell migration
Which maternal disease predisposed to transposition of great vessels?
maternal DM.
Cause of transposition of great vessels?
Abnormal neural crest cell migration leading to problems w/septation.
*heart will be dome shaped & enlarged.
Tricuspid atresia
-what does it require to be viable?
Both ASD and VSD.
-need a way to get to that RV.
Boot shaped heart on CXR
Tetralogy of fallot
-due to RV hypertrophy
Tet spells
In Tetralogy of fallot
- Suddenly develop deep blue skin, nails and lips after crying, feeding, having a bowel movement, or kicking his or her legs upon awakening. Caused by a rapid drop in the amount of oxygen in the blood.
- Toddlers or older children may instinctively squat when they are short of breath. Squatting increases blood flow to the lungs by inc. systemic resistance/pressure which inc pressure in RV so blood shunted thru stenotic pulm art.
Total anomalous pulmonary venous return (TAPVR)
-Pulm. veins drain into right heart circulation; associated with ASD and sometimes PDA to allow for right-to-left shunting to maintain CO.
Dilated coronary sinus, think what?
Pulm HTN.
Frequency of left to right shunts:
VSD > ASD > PDA.
Common cause of VSD?
Fetal alcohol syndrome
Marked distinction btwn foramen ovale and ASD.
- ASD = septum is missing tissue.
- PFO = tissue is not fused properly.
ASD: usually occurs in septum primum or secundum?
-secundum.
which L=>R shunt can result in differential cyanosis?
PDA b/c ductus is AFTER the major aortic branches, so upper extremities will not be receiving deoxy blood!
Common cause of PDA?
congenital rubella
Infantile coarctation
- proximal or distal to ductus artiosus?
- proximal or distal to aortic major branches?
- proximal to ductus arteriosus.
- distal to aortic major branches (so is adult type).
22q11 syndromes
-lead to which cardiac abnormalities?
- truncus arteriosus
- tetralogy of fallot
Turners
-leads to preductal or postductal coarctation?
-obviously preductal cuz you’re born with it.
Mönckeberg (medial calcific sclerosis)
- calcification in which layer of artery?
- which arts are most likely to be affected?
- media.
- no intima involvement.
- seen in radial & ulnar arts.
- “pipestem” arteries on x-ray
Statistical power
(1 - beta)
- probability of finding a true relationship
- beta = probability of missing a relationship when one actually exists.
stats: beta
- probability of committing a type 2 error.
- ie. a study finding that aspirin does not impact platelet function when in fact it does.
type 1 error
- finding a significant difference when one doesn’t actually exist.
- alpha = max probability of committing a type 1 error that a researcher is willing to accept. Usually .05.
- alpha comparable to p-value.
ACE inhibitors can dec. GFR and inc. creatinine.
-can precipitate acute renal failure.
- no AT2 = no constriction of efferent areriole = dec. GFR (dec. filtration fraction).
- especially in pts w/bilat renal art. stenosis.
Avoid ACE inhibitors in which pts?
- bilat renal art stenosis.
- they need their efferent arteriole constricted to get as much filtration fraction/GFR as possible.
Mnemonic for P450 inducers
Chronic alcoholic mona steals phen phen and never refuses greasy carbs.
Mnemonic for P450 inhibitors
MAGIC RACKS in GQ
Mnemonic for P450 substrates
Always Always Always Always think before starting others.
*4 always.
CHF
-mixed venous O2 content. Inc or Dec?
- dec.
- less arterial blood delivered to tissues (due to vasoconstriction & dec. perfusion pressure), so whatever blood is delivered, more O2 sucked out of it.
Pulm edema
-affect on lung compliance?
-dec lung compliance.
presystolic gallop
S4
- unlike S3, S4 is always pathological, even in kids.
- happens during atrial contraction into a stiff/non compliant ventricle. So late diastole, right before systole.
protodiastolic gallop
S3
Carotid sinus
- in which carotid
- proximal or distal to bifurcation?
-internal carotid, right after bifurcation of common carotid.
Cherry hemangioma
- in old or young people?
- does it regress?
- old people
- does NOT regress
*usually much smaller than strawberry hemangiomas.
Which drug can lead to ebstein’s anomaly?
Lithium
Lysyl oxidase
- cross links collagen or elastin?
- fucked up in what disease?
- both
- ehlers danlos
Migratory thrombophlebitis
-should make you think what?
Cancer
-hypercoag = common paraneoplastic syndrome seen in adenocarcinomas of pancreas, colon, or lung.
Metalloproteinases in atheroma
-more of these = more or less risk of rupture?
- more risk of rupture
- released by macros
Common locations for atherosclerosis
Abdominal aorta > coronary artery > popliteal
artery > carotid artery
Can HTN cause cystic medial degeneration?
-what does that predispose to?
- yes.
- aneurysm, dissection.
Stable angina: EKG?
-ST depression or nothing.
Prinzmetal: EKG?
-transient ST elevation
Triggers of prinzmetal angina
-triptans (vasoconstrictors for migrains), cocaine, tobacco.
Unstable/crescendo angina: EKG?
-ST depression
Can you give prinzmetal pts beta-blockers?
do NOT given prinzmetal pts beta-blockers. This will block the vasodilatory effects of beta-2 and make matters worse.
-The coronary vessel dilation is a balance between alpha-1 (constriction) and beta-2 (dilation).
Coronary steal syndrome
Distal to coronary stenosis, vessels are maximally dilated at baseline. Administration of vasodilators (e.g., dipyridamole, regadenoson) dilates normal vessels and shunts blood toward well-perfused areas => dec. flow and ischemia in the poststenotic region. Principle behind pharmacologic stress tests.
How many minutes of ischemia in heart before necrosis?
-20 min
Most common 3 spots for occlusion of coronary.
#1 = LAD #2 = Right coronary art #3 = Left circumflex
How long after MI do neutrophils arrive?
24 hrs.
Is fibrinous pericarditis seen w/subendocardial infarction?
-no, only w/transmural infarct do you get fibrinous pericarditis.
Q waves
-seen w/STEMIs or NSTEMIs?
-seen w/STEMIs (transmural infarcts)
Anterior wall (LAD) -Q waves in which leads?
V1–V4
Anteroseptal (LAD)
-Q waves in which leads?
V1–V2
Anterolateral (LAD or LCX)
-Q waves in which leads?
V4–V6
Lateral wall (LCX) -Q waves in which leads?
I, aVL
InFerior wall (RCA) -Q waves in which leads?
II, III, aVF
What type of pericarditis does Dressler syndrome lead to?
fibrinous
Irreversible cell damage changes
- nuclear pyknosis, karyorrhexis, karyolysis
- plasma membrane damage
- lysosomal rupture
- mito permeability/vacuolization
Which aortic arch is PDA from?
sixth aortic arch
PDA
-Sxs
- palpable thrill over left infraclavicular region due to turbulent flow thru PDA.
- wide pulse pressure (inc. volume in LV = higher systolic, and dec. diastolic cuz some fluid leaving aorta going back into pulm art).
- volume overloads LV, can lead to Sxs of heart failure like failure to thrive & respiratory distress.
Which calcium channel blocker is the most cardioselective?
verapamil
-can lead to gingival hyperplasia.
mnemonic for dilated cardiomyopathy causes:
ABCCCD
- alcohol
- (wet) beriberi
- cocaine
- coxsackie B
- chagas
- doxorubicin
-also hemochromatosis & pregnancy.
Which trinucleotide repeat is associated w/hypertrophic cardiomyopathy?
Friedrich ataxia (GAA)
Löffler syndrome
Endomyocardial fibrosis with a prominent eosinophilic infiltrate.
-causes restrictive cardiomyopathy.
Restrictive/infiltrative cardiomyopathy
-result in systolic or diastolic dysfunction?
-diastolic.
