5/11 Cardio,Mixed

Question 1

Which organ is least vulnerable to arterial occlusion: (spleen, brain, kidney, liver or heart)

Answer 1

Liver because dual blood supply

Exception: liver transplantation because collateral blood supply is severed during transplantation

Question 2

Opening snap of mitral stenosis

Answer 2

Occurs close to mitral valve opening

Question 3

Risk of severe myopathy is increased when statins are given concurrently with

Answer 3

Fibrates (particularly gemfibrozil)
Impair the hepatic clearance of statins and lead to excessive blood levels
Increased risk with current use of niacin and exetimibe, but to a lesser extent

Question 4

a-adrenergic agonists

Answer 4

Increase systolic and diastolic pressure by stimulating a-adrenreceptors in vascular walls, causing vasocontriction
Elevated systemic BP causes reflexive increase in vagal tone, resulting in decrease HR and slows AV node conduction

Question 5

Nitrates SE

Answer 5

Headaches, cutaneous flushing, lightheadedness, hypotension, and reflex tachycardia (due to systemic vasodilation)

Question 6

Number needed to treat (NNT)

Answer 6

Number of patients that need to be treated with a medication to avoid a negative outcome in one patient
1/ ARR = 1 / (control rate- treatment rate)
Lower NNT values represent more beneficial treatments

Question 7

Most important steps for prevention of central venous catheter infections:

Answer 7

Proper hand hygiene
Full barrier precautions during insertion
Chlorhexidine skin disinfection
Avoidance of the femoral insertion site
Removal of the catheter when it is no longer needed

Question 8

Wide, fixed splitting of the 2nd heart soudn

Answer 8

ASD
Can produce chronic pulmonary hypertension as a result of left to right intracardiac shunting
Closure of ASD may be required to prevent irreversible pulmonary vascular sclerosis and a permanent Eisenmenger syndrome

Question 9

Cardiac tissue conduction velocity

Answer 9

AV node (slowest)
Ventricular muscle
Atrial muscle
Purkinje system (fastest)

Question 10

Acquired QT prolongation

Answer 10

Electrolyte imbalances (hypokalemia, hypomagnesemia(
Class IA and III antiarrhythmics (quinidine, sotalol)
Antibiotics (macrolides, fluoroquinolones)
Methadone
Haloperidol

Question 11

Dobutamine

Answer 11

B-adrenergic agonist with predominant activity on B1 receptors
Causes Gs protein GTP binding, activation of adenylyl cyclase and increased production of cAMP, leading to calcium channel activation (positive inotropic and chronotropic effect)

Question 12

Rx of sustained arrhythmias post MI

Answer 12

Amiodarone

Lidocaine

Question 13

Lidocaine

Answer 13

Class IB antiarrhythmic drugs
Binds to inactivated Na channels and rapidly dissociates
Effective in suppressing ventricular tachyarrhythmias induced by rapidly depolarizing and ischemic myocardium

Question 14

Congenital aortic coarctation

Answer 14

Lower-extremity claudication
Blood pressure discrepancy between the upper and lower extremities
Delayed or diminished femoral pulses
Turner syndrome (45,XO) is associated with coarctation of the aorta in up to 10% of cases

Question 15

Jervell and Lange-Nielsen syndrome

Answer 15

One of the most common congenital long-QT syndromes
AR
Accompanied by congenital neurosensory deafness
QT prolongation predisposes to syncopal episodes and possible sudden cardiac death due to torsades de pointes

Question 16

Phospholipid content of amniotic fluid is determined in order to check for:

Answer 16

Fetal lung maturity
Phospholipids, including dipalmitoyl phosphatidylcholine (lecithin), are a major component of pulmonary surfactant

When the lecithin to sphingomyelin (L/S) ratio in amniotic fluid is >2, the fetal lung is considered mature (producing adequate surfactant)

Question 17

Dx Treponema pallidum

Answer 17

Screening and confirmation serologic tests
Screening: RPR or VDRL (serum added to a mixture of cardiolipid, lecithin, and cholesterol)
Confirmatory: FTA-ABS (detects Abs against Treponema)

Question 18

S1 radiculopathy

Answer 18

Sciatica, low back pain that radiates down the leg
Compression of lumbosacral nerve roots
Pain/sensory loss down the posterior thigh and calf to the lateral aspect of the foot
Weakness on thigh extension, knee flexion, foot plantarflexion, absent ankle jerk reflex

Question 19

Tabes dorsalis

Answer 19

Increased incidence in HIV patients
HIV patients develop neurosyphilis more rapidly
Treponema pallidum spirochetes damage dorsal sensory roots > secondary degeneration of dorsal columns
Sensory ataxia, lancinating pains, argyll roberton pupils(accomodate but no rxn), positive Romberg sign, wide-based gait, loss of position and vibration sense

Tertiary neurosyphilis

Question 20

Dopamine

Answer 20

Low doses stimulate D1 receptors in renal and mesenteric vasculature resulting in vasodilation and increase blood flow to these sites

Higher doses increase cardiac contractility by stimulation of beta-1 adrenergic receptors

Higher doses produce generalized vasoconstriction by an alpha-1 adrenergic effect

Question 21

Patients experiences a major depressive episode should be carefully screened for

Answer 21

Past manic episodes to rule out bipolar disorder

Antidepressant monotherapy should be avoided in pateitns with bipolar disorder due to the risk of precipitating mania

Question 22

Ecological study

Answer 22

Frequency of a given characteristic (e.g. Vit D intake) and a given outcome (MS) are studied using POPULATION data

Question 23

Candida Albicans

Answer 23

True hyphae, “germ tubes” incubate at 37 C for 3 hours
Most common opportunistic mucosis
Frequent colonizer of human skin and mucous membrans
Normal inhabitant of the GI tract (including oral cavity) in up to 40% of the population
Common contaminant of sputum cultures

Question 24

MOA of ANP, BNP, and NO

Answer 24

Active guanylyl cyclase and increase conversion of guanosine 5’-triphosphate to cyclic guanosine 3’-5’-monophosphate (cGMP)

Question 25

Blood supply to the proximal ureter

Answer 25

Branches of the renal artery

Distal ureteral ischemia is a recognized complication of renal transplant and causes leakage of urine 5-10 days following transplant

Question 26

Temporomandibular disorder (TMD)

Answer 26

Unilateral facial pain that worsens with jaw movement, headache, ear pain
Symptoms can originate from TMJ derangement, pathologic contraction of muscles of mastication or hypersensitivity of nerves that supply the jaw

Mandibular nerve (trigeminal nerve) supplies the middle ear and the muscles of mastication, can present with otologic symptoms and jaw pain

Question 27

Minimal change disease

Answer 27

Most common cause of nephrotic syndrome in young children
Occurs after URI, immunization, insect bite
Edema, hyperlipidemia, hypoalbuminemia, proteinuria

EM shows diffuse podocyte effacement
Rx: reversible after corticosteroid therapy

Question 28

Methtrexate as a drug of choice for non-surgical treatment of early, unruptured ectopic pregnancy

Answer 28

Competitively inhibits the enzyme dihydrofolate (DHF) reductase, which catalyzed the synthesis of tetrahydrofolate (an integral precursor of DNA synthesis)
DHF reductase inhibition causes the intermediate DHF (dihydrofolate polyglutamate) to accumulate intracellularly

Question 29

What measure of central tendency is resistant to outliers?

Answer 29

THE MODE!!! (outliers are not likely to affect the most frequently observed value in a dataset!)