Neuralgia or pain in the limb denervated by sympathectomy occurs in up to 32% of patients some time after the procedure and is transient.[72] Bilateral T2-T4 sympathectomy reduces the systolic blood pressure without affecting diastolic blood pressure and lowers the heart rate at rest and during exercise.[72]

Reference 72 reads

72. Kestenholz PB, Weder W. Thoracic sympathectomy. Curr Probl Dermatol. 2002;30:64-76. y.

and the original study can be found here.