Green - Genetic Of Cardiovascular Disease

Question 1

Transient loss of consciousness

Answer 1

Syncope

Question 2

Ventricular tachycardia characterized by a change in amplitude and twisting of QRS complexes

Answer 2

Torsades de pointes

Question 3

Phase of fast response action potential.
Depolarization thru sodium influx thru fast channel

Channel coded for by SCN5Agene

Answer 3

Phase 0

Question 4

Partial repolarization by potassium efflux phase (thru volt gate K channels)

Coded by KCND2 and KCND3

Answer 4

Phase 1

Question 5

Calcium influx thru L-type Ca channels

Some potassium efflux thru slow delayed rectifier channels

(Phase ___)

Answer 5

Phase 2

Question 6

Phase;
Repol by K efflux through delayed rectifier channels

Slow activating current first, followed by fast activating current

Coded by: (Slow) KCNQ1
(FAST) KCNH2

Answer 6

Phase 3

Question 7

Genetic defect in cardiac voltage-activated Na and K channels

Loss of function

Prolonged QTc on EKG

Phys/emotional stress triggers syncope or sudden death
(Often due to V-fib)

Answer 7

Long QT Syndrome

Question 8

Long QT syndrome caused by mutation in KCNQ1(phase 3 slow activating K channel) gene

Defective K channels

Ks current reduced

Symptoms triggered by emotional or physical stress.

Exercise more likely to trigger cardiac event than in other long QT syndromes

Answer 8

LQT1

Question 9

Type of long QT syndrome

Mutation in KCNH2 gene (Fast K channels in phase 3)

Symptoms triggered by stress and rest

More likely to have symptoms due to sudden loud noises than other LQTS

Answer 9

LQT2

Question 10

LQTS

Mutation in SCN5A gene which codes fast Na channel in phase 0

Syncope/cardiac arrest most likely in sleep or inactivity, compared to others

Answer 10

LQT3

Question 11

If QTc greater than _____ suspect LQTS

Answer 11

470msec

Question 12

Morbidity and mortality greatly increase for LQTS if QTc > _____

Answer 12

500msec

Question 13

Gain of function mutation in inward rectifying potassium channels

Increased influx of K during repolarization phase

S/s dizziness, a-fib/v-fib, sudden cardiac death

Answer 13

Short QT Syndrome

Question 14

RBBB and ST elevation in right precordial leads

Fast sodium channel loss of function mutation

Answer 14

Brugada syndrome

Question 15

Genes associated with atrial fibrillation:

Answer 15

KCNE2 (regulates K channel)[GOF]

KCNA5 (voltage gated K channel)[LOF]

Connexin 40 (gap junction protein)

Question 16

Most common monogenic cardiac disorder

AD

Gene mutations: myosin heavy chain, myosin binding protein C, cardiac troponin T, I, tropomyosin, myosin light chains

Diverse clinical spectrum; chest pain, intolerance to exercise, symptoms of heart failure
Symptoms worsen w/ age

Increased risk for arrhythmia and sudden cardiac death

Answer 16

Hypertrophic cardiomyopathy

Question 17

S/s: SOB, Edema, Fatigue

Left ventricular enlargement, decreased EF

25-45% due to gene mutations [genes encoding sarcomere proteins; titin, troponin T,C,I desmin, myosin heavy chain]

Decreased left ventricular contraction

Heart muscle weakens over time, leads to heart failure

Answer 17

Dilated cardiomyopathy

Question 18

In postductal coarctation of Aorta, narrowing inferior to ______ will allow for collateral circulation to develop

Answer 18

Ductus arteriosis

Question 19

The fused single aorta has which branches ?

Answer 19

Paired intersegmental arteries

Unpaired vitelline arteries

Paired umbilical arteries

Paired lateral splanchnic arteries