Channelopathies Flashcards¶
Anki-compatible flashcards for LQTS, CPVT, and Brugada Syndrome board review.
Long QT Syndrome (LQTS)¶
Q: What QTc threshold defines definite LQTS? A: QTc ≥480 ms (or ≥460 ms with unexplained syncope) Tags: lqts, diagnosis, qtc, high-yield
Q: What are the 3 most common genetic types of LQTS and their associated genes? A: LQT1 (KCNQ1 - IKs potassium channel), LQT2 (KCNH2 - IKr potassium channel), LQT3 (SCN5A - sodium channel) Tags: lqts, genetics, high-yield
Q: What is the typical trigger for arrhythmic events in LQT1? A: Exercise, especially swimming Tags: lqts, lqt1, triggers, high-yield
Q: What is the typical trigger for arrhythmic events in LQT2? A: Auditory stimuli (sudden loud noises, alarm clocks), emotional stress Tags: lqts, lqt2, triggers, high-yield
Q: What is the typical trigger for arrhythmic events in LQT3? A: Rest and sleep (bradycardia-dependent) Tags: lqts, lqt3, triggers, high-yield
Q: What is the first-line treatment for ALL patients with diagnosed LQTS? A: Beta-blockers (nadolol or propranolol preferred) Tags: lqts, treatment, beta-blocker, high-yield
Q: Which beta-blocker should be AVOIDED in LQTS? A: Metoprolol (less effective, may increase events) Tags: lqts, treatment, avoid, high-yield
Q: What is the characteristic T-wave morphology in LQT1? A: Broad-based T wave Tags: lqts, lqt1, ecg
Q: What is the characteristic T-wave morphology in LQT2? A: Notched or bifid, low amplitude T wave Tags: lqts, lqt2, ecg
Q: What is the characteristic T-wave morphology in LQT3? A: Long isoelectric ST segment with late-appearing, peaked T wave Tags: lqts, lqt3, ecg
Q: What is the inheritance pattern of most LQTS? A: Autosomal dominant (Romano-Ward syndrome) Tags: lqts, genetics, inheritance
Q: What syndrome combines LQTS with congenital deafness? A: Jervell and Lange-Nielsen syndrome (autosomal recessive, homozygous KCNQ1 or KCNE1) Tags: lqts, jervell-lange-nielsen, deafness
Q: What interventions are considered for LQTS patients who have breakthrough events on beta-blockers? A: Left cardiac sympathetic denervation (LCSD), ICD implantation, mexiletine (for LQT3) Tags: lqts, treatment, icd, lcsd
Q: Should asymptomatic patients with genotype-positive LQTS be treated? A: Yes - beta-blockers recommended for ALL genotype-positive patients, even if QTc is normal Tags: lqts, treatment, asymptomatic
CPVT (Catecholaminergic Polymorphic VT)¶
Q: What is the classic arrhythmia pattern seen in CPVT during exercise testing? A: Bidirectional ventricular tachycardia (alternating QRS axis), or polymorphic VT with increasing exercise Tags: cpvt, diagnosis, exercise-test, high-yield
Q: What gene is most commonly mutated in CPVT? A: RYR2 (ryanodine receptor, ~60% of cases) Tags: cpvt, genetics
Q: What is the resting ECG typically like in CPVT? A: Normal (arrhythmias only with exercise/catecholamines) Tags: cpvt, ecg, diagnosis
Q: What is the first-line treatment for CPVT? A: Beta-blockers (nadolol preferred) at maximum tolerated dose Tags: cpvt, treatment, high-yield
Q: What medication is added to beta-blockers for CPVT patients with breakthrough events? A: Flecainide Tags: cpvt, treatment, flecainide, high-yield
Q: What activity restriction applies to ALL patients with CPVT? A: Restriction from competitive sports and strenuous exercise (Class I recommendation) Tags: cpvt, sports, activity, high-yield
Q: What intervention is considered for CPVT patients refractory to medical therapy? A: Left cardiac sympathetic denervation (LCSD); ICD is secondary prevention but can cause "ICD storm" Tags: cpvt, treatment, lcsd
Brugada Syndrome¶
Q: What is the characteristic ECG finding in Brugada Syndrome? A: Type 1 Brugada pattern: Coved ST elevation ≥2 mm in V1-V2 with negative T wave Tags: brugada, ecg, diagnosis, high-yield
Q: What commonly unmasks or worsens the Brugada ECG pattern? A: Fever, sodium channel blocking drugs, vagal stimulation Tags: brugada, triggers, fever
Q: What gene is most commonly mutated in Brugada Syndrome? A: SCN5A (sodium channel, ~20-30% of cases) Tags: brugada, genetics
Q: What is the only proven effective treatment for prevention of SCD in Brugada Syndrome? A: ICD implantation Tags: brugada, treatment, icd, high-yield
Q: In what setting do most arrhythmic events occur in Brugada Syndrome? A: Rest and sleep (similar to LQT3) Tags: brugada, triggers
Q: What should be done for a Brugada patient with fever? A: Aggressive fever control with antipyretics; may need hospitalization if high fever Tags: brugada, management, fever
Q: What is the inheritance pattern of Brugada Syndrome? A: Autosomal dominant with incomplete penetrance Tags: brugada, genetics, inheritance
Cross-Topic Questions¶
Q: A child has exercise-induced syncope and bidirectional VT on exercise testing with normal resting ECG. What is the most likely diagnosis? A: CPVT (Catecholaminergic Polymorphic Ventricular Tachycardia) Tags: cpvt, clinical, high-yield
Q: An infant is found to have QTc of 520 ms and severe bilateral sensorineural hearing loss. What is the diagnosis? A: Jervell and Lange-Nielsen syndrome Tags: lqts, jervell-lange-nielsen, high-yield
Q: A 14-year-old with family history of sudden death has QTc of 490 ms. The T wave is notched in leads V2-V3. What LQTS type is most likely? A: LQT2 (KCNH2) Tags: lqts, lqt2, ecg
Q: Which channelopathy has the HIGHEST mortality rate if untreated? A: CPVT (~30% mortality by age 30 without treatment) Tags: cpvt, prognosis, high-yield
Q: Name 3 medications that should be avoided in ALL patients with LQTS A: QT-prolonging drugs including: Class IA/III antiarrhythmics, macrolides (azithromycin, erythromycin), fluoroquinolones, antipsychotics (haloperidol), methadone, ondansetron. See crediblemeds.org for complete list. Tags: lqts, medications, avoid
Q: What screening is recommended for first-degree relatives of a patient diagnosed with LQTS? A: ECG and genetic testing (if proband's mutation identified) Tags: lqts, screening, family