HRR: genetic channelopathies Flashcards
What is sudden cardiac arrest?
Sudden cessation of cardiac activity with hemodynamic collapse. There is no circulation.
What arrhythmias are associated with cardiac arrest?
Sustained vtach or vfib.
What comorbidities are common with sudden cardiac arrest?
Coronary heart disease, cardiomyopathies, congenital heart disease.
What ion channels can have issues associated with sudden cardiac arrest?
Potassium, sodium, calcium. It could be faulty channels, too few channels, or both.
What is a way to screen for sudden cardiac arrest?
3 generation pedigree.
What is long QT syndrome?
A group of channelopathies that alter myocardial repolarization causing prolonged QT intervals and T wave abnormality.
What is the most common arrhythmia seen in prolonged QT?
Torsade’s.
Uncorrected, what can torsade’s cause?
Vfib and cardiac arrest.
How is inherited long QT diagnosed?
ECG, a finding of a structurally normal heart, and a family history/genetic testing.
When does inherited long QT typically show?
Teenage years.
What is Romano-Ward syndrome?
An autosomal dominant gene mutation resulting in prolonged QT intervals; only the heart is impacted.
What ion channel is mutated in LQTS?
Potassium.
What is the most mutated gene in LQTS?
KCNQ1.
What are common triggers of LQT1?
Exercise and emotional stress.
What are common triggers of LQT2?
Auditory stimuli.
What are common triggers of LQT3?
Sleep or undisturbed rest.
What is Jervell and Lange-Nielson syndrome?
A congenital sensorineural deafness with high cardiac risk. It is a rare LQT.
What is the inheritance pattern of Jervell and Lange-Nielson syndrome?
Autosomal recessive.
What is Andersen-Tawil?
LQT type 7 with muscle weakness and facial dysmorphism. Not inherited.
What is timothy syndrome?
LQTS type 8 with neurodevelopmental abnormalities. Not inherited.
What is the Schwartz score?
A diagnostic tool for LQTS.
What are challenges with diagnosing LQTS?
QT interval variations, transience of QT abnormalities, and considering non-inherited causes.
What do the QTc values of people with LQTS look like?
Many fall within the normal range.
What is the common testing method for LQTS?
NGS panel.
What are common treatments for LQTS?
Most often Beta blockers, but ICD or AED can be useful for certain subtypes. Avoiding the common triggers is also useful. Avoiding QT prolonging medications is super important as well.
What is the inheritance pattern of brugada syndrome?
Autosomal dominant.
What is brugada syndrome?
Cardiac conduction abnormality of the ST segment.
What disease causes consideration for brugada syndrome?
SIDS.
What is a major cause of sudden unexpected nocturnal death in southeast asia?
Brugada syndrome.
What are some clinical findings of brugada syndrome?
Recurrent syncope, vtach, vfib, history of sudden death in family.
Describe brugada syndrome ECG.
Transient or variable changes in the ST segment that can be triggered by sodium channel blockers.
What ion channel abnormalities are seen in brugada syndrome?
Inward sodium/calcium or outward potassium.
What is a common mutation in brugada?
SCN5A, but most don’t have identifiable mutation.
SCN5A can be associated with…
Brugada and LQT3.
How do we treat brugada syndrome in asymptomatic individuals?
Avoid fever, dehydration, and certain drugs. Quinidine can be used but is controversial in asymptomatic individuals, and the same with ICD.
How do we treat brugada syndrome in symptomatic individuals?
Isoproterenol, avoiding triggers, ICD, medications to increase calcium current.
What is seen on ECG in CPVT?
Bidirectional or polymorphic VT.
What is CPVT?
A stress induced release of catecholamines causes dysfunction of calcium ion channel in heart muscle.
What are clinical features of CPVT?
Syncope or sudden cardiac arrest/death.
What is the inheritance of CPVT?
Autosomal dominant.
How is CPVT diagnosed?
Exercise testing; resting ECG will not work!
What are treatments for CPVT?
ICD, beta blockers, activity restrictions.
What is the most common mutated gene in CPVT?
RyR2.
What is short QT syndrome?
Short QT wave on ECG and T wave abnormalities.
What are clinical manifestations of short QT?
Afib and syncope.
What is the inheritance of SQTS?
Autosomal dominant.
What are treatments for SQTS?
Antiarrhythmic medications and ICD for some.
What is different about short QT syndrome?
It is atrial.
What is GINA?
An act that protects patient and family members against genetic discrimination from health insurance companies and employers.
What does GINA not address?
Life insurance, disability insurance, or long-term care insurance.
Who is not covered by GINA?
Military, VA patients, federal employees, employees of very small companies.
