coupling 3 Flashcards
brugada patients have
significantly shortened Q-T interval, indicative of a shortened ventricular action potential
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) can results from
- dominant mutations in RyR2
2. recessive mutations of CasQ2
CPVT patients display
do not display ECG abnormalities at rest, but do display abnormalities upon exercise or infusion of catecholamines.
RyR1 mutations can cause
malignant hyperthermia and central core disease in skeletal muscle.
in the homozygous condition, mutation of CasQ2 would result in
a dramatic loss of lumenal Ca2+ buffering
____ are a standard therapy for CPVT.
b-blockers
why areactivation of b-adrenergic receptors pro-arrhythmogenic?
because of increase in SR Ca content and phosphorylation of RyR2
Heart failure has been suggested to lead to ____
“hyperphosphorylation” RyR2 and contribute in the increased incidence of arrhythmias in patients with heart failure.
b-blockers and other standard therapies are not effective for some____
CPVT patients.
Blocking ____ might provide an effective therapy.
aberrant Ca release via RyR2
Flecainide is a class ____ that blocks ____
1C anti-arrhythmic
cardiac sodium channels.
Tetracaine blocks
RyR2, but at doses too high to be clinically useful.
Flecainide causes a
dose-dependent decrease in the open time of single, sheep RyR2 reconsitituted into planar lipid bilayers
Flecainide reduces the
frequency of spontaneous Ca release events in ventricular myocytes from Casq2-/- mice.
which dz has prolonged QT interval?
both TS and TS2 of timothy syndrome
