What if my panel is negative? How do I manage my patient? Robert Campbell, MD September 30, 2016
NO DISCLOSURES Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Negative LQTS gene panel report Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Negative LQTS gene panel report Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Are you surprised? Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Now what? Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
What was your initial level of clinical suspicion? Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Clinical Scenario A: Syncope • 14 year old female • Negative family history • Vasovagal warning signs • Normal ECG Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Clinical Scenario B: Syncope 14 year old female Schwartz criteria 2012 Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Clinical Scenario B QTc = 690ms Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Patient Truth Positive Negative False Positive True Positive Positive LQTS genotype A B Negative True Negative False Negative
What is your LQTS genotype hit rate? GeneDx data: LQTS is 75-80% and has been the same since beginning too, with minimal increase in detection because the main gene players have always been on the panel… Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Now What …..?? Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
1. Genetic Counselors • Obtain multigenerational family pedigree • Explain the role of genetic testing • Obtain sample • EXPLAIN THE RESULTS Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
2. “Revisit Clinical Diagnosis” • Re-review family history and patient history • Reanalyze all ECGs • Personally review exercise testing results, epi challenge Overestimation of QTc Diagnosing LQTS based on “borderline QTc” Confusion with vasovagal syncope Diagnostic Miscues in Congenital Long-QT Syndrome (Circulation 2007;115;2613-2620) Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
3. Have you constructed a complete and correct multigenerational family pedigree? Have you tested the right family member? died in old age, hx of syncope Vfib d.5y SCA SCA ~40y SCA driving ICD KCNQ1 + 53y 36 y SCA ?valve abnl SCA 6 days Cocaine post partum 15y ? ? QTc 508 21y Syncope,chest pain SCA ICD ICD 17y Palpitations at rest ICD Prev nl card. Eval KCNQ1 + ? 5 ? ? ? 5 KCNQ1 @11y KCNQ1+ KCNQ1+ 16 Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology No screen
4. Do you have cascade testing on first degree relatives? 80y d. 32y d. 22y MVA MVA d. 55y 45y d. 15y 55y 44y MVA ‘fell asleep Playing outside MVA At the wheel’ 16y 14y RYR2 neg. Sudden Cardiac Arrest CPVT RYR2 positive Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology 17
5. Gene testing • Era of the genotype • Research versus clinical • Panel density Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
6. Consider Comprehensive Arrhythmia Panel? CPVT vs LQTS Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
7. Next level genetic testing Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
8. Center of Excellence 2 nd Opinion Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
9. SADS Scientific Advisory Board review Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Ultimately …. In the absence of a positive genotype … Confirm a correct clinical diagnosis Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Ultimately ….. When uncertain regarding diagnosis will you: Underdiagnose? Overdiagnose? • Under-test • Over-test • Under-treat • Over-treat • Under-restrict • Over-restrict • Under-worry • Over-worry • ? Under-protect from SCA • Better protected from SCA Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
Summary • Negative genotype does not exclude disease • Negative genotype may confuse/confound diagnosis, so …. take a deep breath and reconsider all clinical clues • Consider second opinions, COE • Ultimate goal is correct diagnosis management • Consider repeating genotype in the future Children’s Healthcare of Atlanta | Sibley Heart Center Cardiology
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