[SCD-FORUM] 154E Long QT. Dr. Schwartz

[SCD Symposium]

Dear Dr. Stefani:
Interesting case. The occurrence of sudden deaths in both maternal and
paternal side calls for great caution in interpretation and raises the
possibility of two independent mutations. I would not trust the ECG pattern
to guide my therapeutic decision. Genetic testing is essential and should
involve all 9 (perhaps 10) LQTS genes. I am willing to genotype your little
boy in my laboratory. Our max screening time is 6 months and our success
rate is 70-75%. 
As to your observations. Never mind if Propranolol does not shorten the
QTc, it should still be used at full dose. I would not use Flecainide which
has Ikr blocking effect! We use mexiletine and in LQT3 we have approx.
90-100 ms QTc shortening. What information is giving you the Holter
recording and exercise? Any unusual pattern nighttime? I will be glad to
help, if you wish.
Peter J. Schwartz