Rx_1.13 (Cardio)

Question 1

Histologic description of Aschoff bodies

Answer 1

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

Question 2

Anatomical location of jugular vein

Answer 2

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

Question 3

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

Answer 3

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

Question 4

Common features of Turner’s Syndrome

Answer 4

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

Question 5

Fick principle (for calculation of CO)

Answer 5

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

Question 6

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

Answer 6

damaged right phrenic nerve

Question 7

Possible severe consequence of untreated UTI

Answer 7

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

Question 8

Common dangerous feature of acute kidney failure

Answer 8

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

Question 9

ECG finding in hyperkalemia

Answer 9

• peaked T waves

Question 10

Presentation of Staph Aureus endocarditis

Answer 10

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

Question 11

Characteristics of S. aureus

Answer 11

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

Question 12

Fxn of carotid sinus baroreceptors

Answer 12

• 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

Question 13

Fxn of aortic arch baroreceptors

Answer 13

• 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

Question 14

Characteristics of phases 1-4 of ventricular AP

Answer 14

• 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

Question 15

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

Answer 15

• 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

Question 16

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

Answer 16

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

Question 17

Tx for pregnant woman w/IVC compression

Answer 17

• lie on left side/prop up right hip

Question 18

Class of antiarrhytmics that prolong repolarization

Answer 18

• Class III antiarrhythmics
  
  • amiodarone
  • sotalol

Question 19

Characteristics of sotalol

Answer 19

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

Question 20

Acebutolol: MOA, use

Answer 20

• B₁- selective antagonist
• class II antiarrhymic agent
• use: suppresses ventricular ectopic beats

Question 21

Esmolol: MOA, use

Answer 21

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

Question 22

Metoprolol: MOA, use

Answer 22

• B₁ - selective antagonist
• class II antiarrhymic

Question 23

Propanolol: MOA, use

Answer 23

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

Question 24

Dx + possible causes?

Answer 24

• 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)

Question 25

"5 T's" of neonatal cyanosis

Answer 25

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

Question 26

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

Answer 26

* transposition of great vessels

Question 27

Tx of transposition of great vessels

Answer 27

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

Question 28

Rates of conduction in cardiac electrical system

Answer 28

* 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

Question 29

Tx for Viridans strep endocarditis

Answer 29

Penicillin G

Question 30

Mitral stenosis murmur

Answer 30

* late, rumbling diastolic murmur at apex

Question 31

Signs of acute rheumatic fever

Answer 31

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