Effects of right and left stellate ganglion block on blood pressure and QT-QTc intervals in patients with primary Raynaud’s phenomenon

Aim: To examine the effects of right and left stellate ganglion block (SGB) on blood pressure and the RR, QT, and QTc intervals in patients with primary Raynaud’s phenomenon. Materials and methods: Right and left SGBs were performed with 8 mL of 0.5% bupivacaine in 10 patients with primary Raynaud’s phenomenon. There was an interval of at least 1 week between the right and left blocks of each patient. Th e blood pressure and the RR and QT intervals were measured before the block and 5, 10, 15, 20, and 30 min after the block. The QTc interval was calculated using Bazett’s formula. Results: The RR and QT intervals were longer 20 and 30 min after right SGB when compared with the preblock value (P = 0.037 for RR and P = 0.008 for QT). The QT and QTc intervals 20 and 30 min aft er left SGB were shorter than the preblock values (P = 0.011, P = 0.012 for QT; P = 0.013, P = 0.009 for QTc). Conclusion: We conclude that right SGB prolongs the RR and QT intervals while left SGB shortens the QT and QTc intervals in patients with primary Raynaud’s phenomenon. Precautions must be taken, taking into account the risk of fatal arrhythmia following right SGB.