Role of α₁-Blockade in Congenital Long QT Syndrome

8 patients (5 females, 3 males; mean age 31+/-15 years) with a diagnosis of congenital long QT syndrome (LQTS), 7 of whom had a history of syncope and/or cardiac arrest and documented spontaneous torsade de pointes.

Alpha1-blockade (doxazosin 2 mg/day) for 1 week added to baseline beta-blockade therapy.

Baseline beta-blockade therapy alone (propranolol 30-90 mg or atenolol 50 mg).

Changes in Bazzet-corrected QT (QTc) and QTp (QTpc) intervals in the supine and standing position before exercise and in the early recovery phase after exercise, and the slopes of the QT interval to heart rate during exercise.surrogate