LONG QT SYNDROME history, types, clinical features, diagnosis, risk stratification, treatment

1. PRESENTOR- Dr. G. APARANJI
DM CARDIOLOGY RESIDENT@SJICR,BANGALORE

3. Anton Jervell and Fred Lange-Nielsen in 1957-
Jervell, Lange- Nielsen syndrome.

4. • Romano et al. in 1963 andWard in 1964
Romano-Ward syndrome.
• AD inheritance

5. • The Long QT syndrome (LQTS) can be inherited or acquired .
Inherited long QT syndrome
(>480 msec).
INTRODUCTION

9. 17 genes
Five genes, (LQT1,2,3,5,6) with over 200 mutations have been discovered.
• About 95% of LQTS cases are caused by mutations of the potassium genes.

11. 80%
5%

12. “LQTS related”disorders

13. MECHANISM OF LONG QT
Loss of function potassium channel
Gain of function SCN5A sodium-channel

15. Triggered activity

16. functional reentry

17. 35 to 40
• Loss of function mutation in the KCNQ1 gene.
KCNQ1
KCNE1) Iks channel.

18. 25 to 40
• Loss of function mutation in the KCNH2
KCNH2
KCNE2) Ikr channel.

19. 5 to 10 percent
SCN5A- I Na channel(Nav1.5).

23. gene-specific triggers, ECG patterns, and response to therapy

24. triad

26. • Cardiac manifestations ofTS

27. • Extracardiac abnormalities

28. • Calmodulin-positive LQTS-
• TRIADIN KNOCKOUT (TKO) SYNDROME

30. ECG look for QT prolongation andT wave changes

32. • Upper limit of QTc in females is 460 msec and males it is 450 msec.

35. LQT1
exaggerated lengthening of the QT interval as the heart
rate declines during early and late (eg, 1 and 4 minutes) recovery

36. LQT2
is exaggerated lengthening of the QT interval as the heart rate declines during late
recovery (eg, > 4 minutes) after exercise.

37. shorten during exercise and in recovery in patients with LQT3
LQT3

39. high clinical suspicion
Class I recommendation).
intermediate clinical suspicion
(Class II
recommendation).
Class I recommendation
Class II recommendation
Class I recommendation

41. • Based on clinical ,ECG and genetic parameters

42. cumulative survival rate

43. Risk Stratification –Clinical Factors
Clinical factors are –Age ,Sex and syncope
Age and Gender

45. SYNCOPE
• Adolescents (age 10 to 20 years)-
• Adults (age 18 to 40 years)

47. Risk Stratification – ECG Changes
DURATION OF QTc INTERVAL- RISK
530 ms
500 and 549-
550 ms

50. Risk Stratification - Genetic Parameters
• LQTS 1
transmembrane/ pore region

51. • LQTS2

59. sodium channel blockers

60. Rationale for LCSD

69. cisapride

76. ABORTED SCD IN A JERVELL LANGE NIELSEN
SYNDROME

80. QTc of 663 msec

81. FRACTURED EPICARDIAL LEAD

82. AAI

83. QTc 462 msec

84. • Learning points from this case