Rx_1.13 (Cardio) Flashcards Preview

USMLE Step 1 > Rx_1.13 (Cardio) > Flashcards

Flashcards in Rx_1.13 (Cardio) Deck (31)
1

Histologic description of Aschoff bodies

  • aschoff body = indicates rheumatic heart dz
  • aschoff body = non-caseating granuloma w/multi-nucleated giant cells

2

Anatomical location of jugular vein

  • within carotid sheath
  • lateral to the carotid artery
  • anterior to the vagus nerve

3

Young girl w/hypertension @ extremities + narrowing of thoracic aorta on aortogram ==> dx?

  • coarctation of aorta
  • possibly Turner Syndrome (XO), esp. if other features present

4

Common features of Turner's Syndrome

  • short stature
  • webbed neck
  • coarctation of aorta
  • bicuspid aortic valve
  • streak ovaries 
  • primary amenorrhea

5

Fick principle (for calculation of CO)

CO = (total O2 body consumption)/(arterial O2 - venous O2)

6

Intact right hemidiaphram elevated above left on (inspiratory) xray ==> dx?

damaged right phrenic nerve

7

Possible severe consequence of untreated UTI

  • pyelonephritis
  • sepsis
  • acute kidney failure ==> hyperkalemia

8

Common dangerous feature of acute kidney failure

  • indicators = high BUN, high creatinine
  • consequence = hyperkalemia ==> cardiac arrhytmias

9

ECG finding in hyperkalemia

  • peaked T waves

10

Presentation of Staph Aureus endocarditis

  • acute onset
  • IV drug user
  • tricuspid valve ==> systolic murmur
  • septic emboli from right side ==>
    • cough
    • pleuritic chest pain
    • diffuse pulmonary infiltrates
    • pyoneumothorax

11

Characteristics of S. aureus

  • gram +, facultative, cluster-forming anaerobe
  • catalase +, coagulase +
  • beta-hemolytic
  • produces golden yellow pigment in culture

12

Fxn of carotid sinus baroreceptors

  • facilitate response to hypotension
  • sends afferent signals via glossopharyngeal nerve to medulla to control sympathetic outflow
    • hypotension ==> decreased firing ==> increased sympathetic outflow
  • transduce pressures from 50-180mmHg

13

Fxn of aortic arch baroreceptors

  • respond to increases in blood pressure
  • less sensitive than carotid sinus
    • respond to stretch caused by BP @ 110-200 mmHg
    • receptors do not fire in hypotensive state

14

Characteristics of phases 1-4 of ventricular AP

  • 0 = rapid upstroke and depolarization
    • voltage-gated Na channels open
  • 1 = initial repolarization
    • inactivation of voltage-gated Na channels
    • K channels begin to open
  • 2 = plateau
    • Ca  influx from volt-gate Ca channels balances K efflexu
    • Ca influx triggers release of Ca from sarc reticulum and myocyte contraction
  • 3 = rapid repolarization
    • massive K efflux due to opening of slow K channels and close of Ca channels
  • 4 = resting
    • high K permeability through K channels

15

fixed and widely split S2 ==> dx? (+mechanism)

  • Atrial Septal defect
  • normal cause for splitting:
    • inspiration ==> decreased intrathoracic pressure ==> increased venous return @ RA/RV  ==> delayed closure of pulmonic valve
  • in ASD:
    • shunt ==> constant blood flow across from L => R leads to increased flow into RA/RV ==> constant delay of pulmonic valve independent of breath

16

3rd trimester pregnant woman + light-headedness when supine ==> dx?

  • Inferior vena cava compression by large uterus ==> reduced cardiac output

17

Tx for pregnant woman w/IVC compression

  • lie on left side/prop up right hip

18

Class of antiarrhytmics that prolong repolarization

  • Class III antiarrhythmics
    • amiodarone
    • sotalol 

19

Characteristics of sotalol

  • b-blocker
  • antiarrhytmic w/class II and class III properties

20

Acebutolol: MOA, use

  • B- selective antagonist
  • class II antiarrhymic agent
  • use: suppresses ventricular ectopic beats

21

Esmolol: MOA, use

  • rapid-acting B antagonist
  • class II antiarrhytmic
  • use = IV control of afib

22

Metoprolol: MOA, use

  • B1 - selective antagonist
  • class II antiarrhymic

23

Propanolol: MOA, use

  • nonselective B antagonist
  • class II antiarrhytmic
  • use:
    • slows sinus rhythm
    • prolonged PR interval

24

Dx + possible causes?

  • Torsades de pointes
    • potentially fatal rapid ventricular rhythm
  • causes
    • hypokalemia
      • can be caused by K channel blockers (e.g. sotalol)
    • congenital syndrome
      • e.g. long QT syndrome
    • quinidine (antiarrhythmic)

25

"5 T's" of neonatal cyanosis

  • Tetrology of Fallot
  • Transposistion of the great vessels
  • Truncal arteriosus
  • Tricuspid atresia
  • Total anomalous pulmonary venous return

26

cyanotic newborn immediately after birth + mother w/DM ==> dx?

  • transposition of great vessels

27

Tx of transposition of great vessels

  • create an atrial shunt if none exists
    • give prostaglandin E1 to maintain patent ductus arteriosis
  • corrective surgery once infant is stabilized

28

Rates of conduction in cardiac electrical system 

  • fastest to slowest: 
    1. His-purkinje (1-4 m/s)
      1. large cells, many gap jxns
    2. SA node (1 m/s)
      1. small cells, few gap jxns
      2. less time to depolarize
    3. AV node (0.05 m/sec)
      1. small cells, few gap jxns
      2. slow-rising/low-amp APs

29

Tx for Viridans strep endocarditis

Penicillin G

30

Mitral stenosis murmur

  • late, rumbling diastolic murmur at apex

31

Signs of acute rheumatic fever

  • FEVERSS:
    • Fever
    • Erythema marginatum
      • nonpruritic, circular, pink eruption on trunk
    • Vavular damage
    • Erythrocyte sedimentation rate increased
    • Red-hto joints
    • Subcutaneous nodule
    • Saint Vitus' dance

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