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