Cardiology Flashcards
reliability of a test is quantified using
maximal when?
CV coefficient of variation. standard deviation of repeated measurements divided by the mean.
maximal when random error is minimal
another name for validity of a test
accuracy
sensitivity vs specificity
ability to identify true presence of a disease vs ability to identify true absence of disease
S3 sound (frequency, mech, occurs when?)
low frequency sounds occuring just after S2
associated with increased left vent ESV. (sudden deceleration of blood)
occurs in left ventricular systolic failure. and mitral valve regurge.
normal in athletes and children and pregnant women
bulging of intraventricular septum
occurs in cardiac tamponade,
bulging of septum into left vent. allows for increased volume in r. vent to allow for more blood to flow in
during inspiration this causes pulsus paradoxus
aortic valve sclerosis vs stenosis
sclerosis causes murmur (mid systolic)
stenosis causes S3 sounds which is indicative of l. vent. failure
dexrazoxane
a iron-chelator that prevents doxorubicin cardiotoxicity
why is it easier to hear a heart sound at lateral decubitus position when pt fully exhales?
b/c the volume in lung is decreased and heart is closer to the wall
what are valsalva maneuvers and positional changes used for in heart sounds? what effect do they have on MR, MS, hypertrophic cardiopathy, and MVP?
to increase or decreases blood flow to heart. helps to distinguish between systolic mummers (aortic stenosis vs mitral regurg and mitral valve prolapse)
increase blood to heart (Valsalva release, supine)
aortic stenosis-increase in sound
mitral regurg/ hypertrophic cardiomopathy- decrease in sounds
mitral valve prolaspe- decrease in sound, and later onset of opening click (sudden tensing of cordae tendineae)
decrease blood to heart (Valsalva maneuver-bearing down. standing up)
cardiomyopathy increases in sound (b/c afterload is decreased and LV vol is increased)
aortic stenosis- decrease in sound
mitral regrug-decrease in sounds
MVP- increase in sound and earlier onset of opening click
mitral valve prolaspe vs mitral valve stenosis
both have opening sounds: MVP-opening click
MS-opening snap
MS-diastolic murmur and MVP-mid-sysolic murmur
what effect does inspiration have on heart sounds?
increase intensity of all right heart sounds
causes of subacute endocarditis? how do you differentiate the two
acute endocarditis-valve it prefers
subacute- enteroccoccus (after GI/GU procedures) and s. viridans (after dental procedures)
enterococcus can grow in salt and s. viridans is optochin resistant. also viridans causes damage to already abnormal heart valves (congential, or rheumatic fever-high pressure valves first (mitral>aortic»>tricuspid))
acute-s. aureus (tricuspid)
pulmonary complication of s. aureus endocarditis
septic emboli in lungs=multiple hemorrhagic pulmonary infarcts. hemorrhagic b/c of dual bloos supply (pulmonary and bronchial arteries)
myocardial hybernation vs myocardial stunning
- ischemia-induce reversible loss of contractile function, reversible with reperfusion (CABG or ballon angioplasty)
- less severe form of hibernation- (recovers after hrs to days), repetitive stunning can result in hibernation
ischemic pre-conditioning
development of resistance to infarction by cardiac myocytes previously exposed to repetitive non-lethal ischemia
ventricular remodeling
increased hemodynamic load results in changes in mass, volume, and shape of heart
ECG changes and associated problems: prolonged QT high voltage in precordial leads prolonged QRS absent P waves/variable R-R ST elevation
- torsade the pointes
- ventricular hypertrophy
- ventricular dyssynchrony-a common cause is bundle branch block
- atrial fib
- MI
which wall of heart forms most of the anterior border
right ventricle
brain natriuretic peptide
released from ventricles in response to high pressure. like ANP
both activate guanylate cylase cause increase in cGMP leading to vasodilation (decrease BP). can also cause diuresis/natriuresis
marijuana- active ingredient, receptor, effects (5), immediate symptoms (2), detection time
contains THC, stimulates cannabinoid receptors to produce mild euphoria with laughing behavior, slowed reflexes, dizziness, impaired memory, and short term memory loss
- immediate symptoms-rapid heart rate and conjunctival injection
- can be detected up to 30 days after use
neuro drug that causes
- miosis
- bradycardia
- nystagmus
- hypersalivation
- opiate
- GHB (gamma hydroxybutyric acid), opiate, or benzodiazepine use
- PCP
- ketamine (NMDA receptor antagonist)
when can pts information be disclosed to others? what act is responsible for this rule? are there any exceptions?
only when there is documented permission from the pt (even to spouse, loved ones etc…)
HIPAA (health insurance portability and Accountability act)
only exception is if the pt with incapacitated.
treatment of coagulase-negative staph infections. why no penicillin?
vancomycin with or without rifampin or gentamicin due to widespread antibiotic resistance of S. epidermis
effect of class IC anti-arrhythmics on QRS duration and QTc vs class III
class IC (i.e. flecainide* and propafenone) "Can I have Fries Please?" -potent sodium blockers that prolong QRS interval at faster heart rates (use-dependence)
- class III (AIDS- amiodarone, ibutilide, dofetilide*, and sotalol)
- block outward repolarizing potassium current and demonstrate reverse use-dependence (slower the heart rate the more the Qtc is prolonged) no effect on QRS-depolarization has already passed