5/12 Cardio, Mixed

Question 1

Norepinephrine extravasation

Answer 1

Blanching of vein into which NE is being infused, induration and pallor of tissues surrounding the IV site
NE causes intense a1 mediated vasocontriction and tissue necrosis
Rx: local injection of an alpha1 blocking agent, (phentolamine)

Question 2

Down Syndrome most common cause

Answer 2

Maternal meiotic nondisjunction

Question 3

Vessels to which organs are most commonly involved in polyarteritis nodosa?

Answer 3

Kidneys, heart, liver, GI tract, Skin (1/3)

Lung is VERY RARELY INVOLVED

Question 4

Descending thoracic aorta in relation to the esophagus and left atrium

Answer 4

Left atrium (anterior)
Esophagus
Thoracic aorta (posterior)

Question 5

Ventricular response in afib

Answer 5

Dependent on the transmission of abnormal atrial impulses through the AV node
The AV node refractory period regulates the number of atrial impulses that reach the ventricle and determines the ventricular contraction rate in conditions where the atria undergo rapid depolarization

Question 6

Complete 3rd degree AV block: what paces the ventricles?

Answer 6

AV nodal cells become pacemakers when conduction between the SA and AV nodes is impaired

Question 7

Location of IVC at L1 on CT

Answer 7

IVC lies anterior to the right renal artery and to the right of the aorta
IVC is formed by the union of the right and left common iliac veins at the L4-L5 level

Question 8

Effects on Nitroprusside

Answer 8

Venous and arterial vasodilator

Decreases left ventricular preload and afterload

Question 9

Angioedema

Answer 9

1) Mast cell activation (T1H-IgE mediated, Direct via opioids)
2) Excess bradykinin (ACE inhibitors, C1 inhibitor deficiency)-no pruritus or urticaria
Tongue, lips, eyelids

Question 10

MOA of pulmonary HTN due to L sided Heart Disease

Answer 10

Increases pulmonary venous pressure and congestion
Leads to passive increase in pulmonary arterial pressure, which is made worse by reactive vasoconstriction and structural remodeling of the pulmonary vasculature 2nd to impaired NO availability and increased endothelial expression

Question 11

Isolated mitral stenosis vs. combined mitral/ aortic stenosis

Answer 11

Isolated mitral stenosis elevates left atrial diastolic pressure and can cause elevated pulmonary capillary wedge pressure, pulm HTN, decrease pulmonary vascular compliant, RV dilatation and tricuspid regurg.
Diastolic pressure in the left ventricle is usually near normal or even decreased with severe mitral stenosis.

Question 12

Rx of severe hypertension

Answer 12

Fenoldopam is a short acting selective peripheral dopamine 1 receptor agonist (with little to no effect on a or b adrenergic receptors)
Given IV (especially in patient with renal insufficiency)
Activates adenylyl cyclase and increases cAMP, resulting in vasodilation with a corresponding decrease in BP
Increases renal perfusion, promotes diuresis and natriuresis

Question 13

Dihydroergotamine

Answer 13

Ergot alkaloid commonly used to treat acute migraine HA
May induce vasospastic angina as it constricts vascular smooth muscle via stimulation of both a-adrenergic and serotonergic receptors

Can trigger prinzmetal angina; other triggers: cigarette smoking, cocaine/amphetamies, dihydroergotamine/triptans

Question 14

Dystrophic calcification

Answer 14

Hallmark of cell injury and death

Occurs in all types of necrosis (coagulative, fat, caseous, liquefactive) in the setting of normal calcium levels

Question 15

What determines the degree of right to left shunting and resulting cyanosis in patients with tetralogy of fallot?

Answer 15

Degree of right ventricular outflow tract obstruction

Question 16

Class III antiarrhythmic drugs (amiodarone, sotalol, dofetilide)

Answer 16

Predominantly block K channels and inhibit the outward K currents during phase 3 of the cardiac action potential, thereby prolonging repolarization and total action potential duration

Question 17

Hibernating myocardium

Answer 17

Left ventricular systolic dysfunction due to reduced coronary blood flow at rest that is partially or completely reversible by coronary revascularization

Question 18

Ventricular septal defect (VSD)

Answer 18

Typically presents in neonatal period after pulmonary vascular resistance has declined
Clinical presentation depends on the size of the defect, which ranges from asymptomatic holosystolic murmur (small VSD) to heart failure (large VSD)

Question 19

Paradoxical embolism

Answer 19

Occurs when a thrombus from the venous system crosses into the arterial circulation via an abnormal connection between the R and L cardiac chambers (e.g. patent foramen ovale, atrial septal defect, ventricular septal defect). Atrial left to right shunts cause wide and fixed splitting of S2 and can facilitate paradoxical embolism due to periods of transient shunt reversal (straining or coughing)

Question 20

Clopidogrel

Answer 20

Irreversibly blocks the P2Y component of ADP receptors on the platelet surface and prevents platelet aggregation
As effective as aspirin in the prevention of cardiovascular events in patients with coronary heart disease (use in patients with aspirin allergy/asthma/rhinitis)

Question 21

Sarcomere

Answer 21

Distance between 2 z line
Thin (actin) filaments in the I band are bound to structural proteins at Z line
Unbound ends of actin project into the middle of the sarcomere where they interact with thick (myosin) filaments during muscle contraction
Thick (myosin) filaments in the A band are bound to structural proteins at the M line

Question 22

The anterior pituitary is derived from which embryonic layer

Answer 22

Surface ectoderm (Rathke’s pouch, anterior pituitary)

Question 23

Hemoglobin A2

Answer 23

A2D2, 2.5% of total hemoglobin

Elevated in beta-thalassemia to compensate for the decreased synthesis of HbA due to B globin chain underproduction

Question 24

Obstructed right brachiocephalic vein

Answer 24

Brachiocephalic vein drains the ipsilateral jugular and subclavian veins.
The bilateral brachiocephalic veins combine to form the SVC.
Brachiocephalic vein obstruction causes symptoms similar to those seen in SVC syndrome but only on one side of the body

Question 25

Pseudomonas aeruginosa

Answer 25

Major pathogen in BURN patients
Gram negative, catalase positive, non-lactose fermenter
Rx: Cefepime

penicillin (Ticarcillin, piperacillin), Cephalosporins (Ceftazidime, cefepime), aminoglycosides, fluoroquinolones (ciprofloxacin, levofloxacin), carpapenems (imipenem, meropenem)

Question 26

Pancoast tumors

Answer 26

Non-small cell lung cancers (SCC, adenocarcinoma)
Arise near superior sulcus
(Brachial plexus) Ipsilateral shoulder pain, upper limb paresthesias, areflexic arm weakness
Horner’s syndrome (sympathetic ganglia): ptosis, miosis, anhydrosis

Question 27

SE of amphotericin B

Answer 27

Nephrotoxicity
Anemia (decreased EPO production)
Electrolyte abnormalities: hypokalemia, hypoMg

Question 28

Von willebrand dx

Answer 28

Hx of mucosal bleeding (gingival bleeding, epistaxis, menorrhagia)
Normal platelet levels, prolonged bleeding time (due to impaired platelet functioning)

Question 29

Klinefelter syndrome

Answer 29

47, XXY
Intellectual disability, sparce facial/body hair, gynecomastia, cyptorchidism, infertility, long legs (tall stature), azoospermia
Usually not diagnosed until puberty

Question 30

Clozapine

Answer 30

Treatment resistant schizophrenia
Schizophrenia associated with suicidality

SE: agranulocytosis, seizures, myocarditis, metabolic syndrome

Question 31

Peripheral chemoreceptors

Answer 31

Found in carotid and aortic bodies
Primary sites for sensing arterial PaO2
Stimulated by hypoxemia
Also stimulated by increased PaCO2 and blood H

Question 32

Reversible competitive antagonists

Answer 32

Competitive=change ED50= shift right
Noncompetitive=change Emax=shift down

*Effect of reversible competitive antagonist can be overcome by high concentrations of agonist

Question 33

Maximum acceptable recurrence rate

Answer 33

8%- (0.40X8%=3.2%)= 4.8%

Relative risk reduction = (absolute risk control - absolute risk treatment) / absolute risk control

Question 34

Characteristics of drugs predominately eliminated by the liver

Answer 34

Eliminated by bile and feces

High lipophilicity and high volume of distribution

Question 35

Fat embolism syndrome

Answer 35

Acute-onset neurologic abnormalities, hypoxemia, petechial rash in patient with severe long bone/pelvic fracture

Fat microglobules in pulmonary arteries