Flashcards in 2/22 Deck (104)
Congenital long QT syndromes
-disorder of myocardial repolarization, typically due to ion channel defects.
-mechanical contraction of ventricles.
-QRS wave til end of T wave (repol).
-long QT interval predisposes to Torsades
-congenital long QT
-pure cardiac phenotype, no deafness
Jervell and Lange Neilson syndrome
-congenital long QT
What is neg. feedback on renin?
-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?
-more so w/spironolactone
What causes type 4 renal tubular acidosis
-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
-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
-hepatic overprod. of VLDL.
Ligand for LDL receptor?
-are they are risk for premature CAD?
-their LDL and HDL levels are fine.
-CAD risk main indicator is HDL levels.
What types of drugs have a low volume of distribution?
-plasma protein bound
Whats the average total body water?
-plasma volume = 3 L
-interstitial = 11 L
*so about 14 L out of 41 L is extracellular fluid.
-fern-leaf pattern cutaneous marks following a lightning strike. lol.
-what is it?
-what can it point to?
-electrical activity of papillary muscles.
midline of EKG
-cells are depolarized
-no more current flowing
which interval = systole?
-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.
-which segment is elongated?
-AV nodal block aka junctional block.
2nd deg. heart block: Mobitz 1
Progressive elongation of PR interval until one P wave not followed by QRS, then cycle repeats.
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
-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
-no discrete P waves (atrial depol)
Atrial flutter: describe tracing
-A rapid succession of identical, back-to-back atrial depolarization waves.
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.