Arrhythmias genetics

Question 1

Sudden cardiac death

Answer 1

cessation of cardiac mechanical activity (no circulation)
300k people each year
Structural heart disease, genetic channelopathy
Main cause: hypertrophy, coronary artery anomaly

Question 2

Ion channels

Answer 2

Alpha units are pore forming and mediate currents, beta units are regulatory

Channelopathies-alter ion channel current and disrupt the AP–electrical instability, Mutations in genes coding for ion channel proteinsq

Question 3

Inherited arrhythmias

Answer 3

pts may be affected at any age, Syncope and SIDS are common findings

Other symptoms: hypotension, bradycardia/tachycardia

Question 4

Long QTc syndrome

Answer 4

1/3k-7k
prolonged QT interval and T wave abnormalities on EKGs and TdP

Present with syncope and SCD due to VT (V tach), typically TdP- can cause seizures, syncope on exercise

The longer the QTc, the increased risk

Acquired: MI, hypo K/Mg/Ca, autonomic influences, drugs, hypothermia
Congenital: RWS,

Question 5

LQTS Genetics

Answer 5

1’ electrophysiologic disorder due to ion channel abnormalities
called Romano-Ward Syndrome (RWS)
Autosomal dominant disorder (Reduced penetrance, Genetic heterogeneity)

Question 6

Jervell and Lange Nielson syndrome

Answer 6

Congenital, profound bilateral sensorineural deafness and QT prolongation

Recessive Autosomal (type 1 90%)

Question 7

LQTS: genetic testing

Answer 7

Differentiate hereditary arrhythmia from acquired arrhythmia

Detection of 75%

Question 8

Treatment and management for LQTS

Answer 8

Pacemakers
Implantable cardioverter defib
Left cardiac sympathetic denervation (

Question 9

Brugada syndrome (BrS)

Answer 9

Cardiac conduction abnormalities, STE in V1-V3
Ventricular Arrhythmias
Presents as chest pain palpitations SUNDS
more in males
Brugada like EKG drug induces: Antiarrhythmics 1A, !C, 4, 2
Antianginal drugs: CCB nitrates
Psych: TCA, phenothiazines, SSRI
Cocaine
Alcohol

Question 10

Brugada genetics

Answer 10

AD: reduced penetrance

Apha subunit of the cardiac votage gated Na channel

Sodium channelopathy, genetic modifiers environmental factors,

Question 11

BrS diagnosis

Answer 11

Change lead position, provocative drug testing

Question 12

Catecholaminergic polymorphic V Tachy (CPVT)

Answer 12

Triggered by exercise or acute emotion

can lead to V tach

high penetrance
Diagnosis- exercise stress test