Left stellate ganglion block has only small effects on left ventricular function in awake dogs before and after induction of heart failure. (Institut für Klinische Anaesthesiologie, Heinrich-Heine-Universität, Düsseldorf, Germany) Anesth Analg 2000;91:787–792.

This study investigated the effects of left stellate ganglion block (LSGB) in chronically instrumented awake dogs before and after the induction of pacing-induced congestive heart failure. Twelve dogs were instrumented for measurement of global hemodynamics (LV pressure LVP]), its first derivative, cardiac output (CO), and regional myocardial function (systolic posterobasal, segment length shortening, mean velocity SLmv]). Before the induction of heart failure, LSGB did not affect CO and SLmv, but slightly reduced LVP. Conclude that even during heart failure the hemodynamic changes after LSGB are small, confirming a broad margin of safety.
Comment by James E. Heavner, D.V.M., Ph.D. The outcomes of this very nice animal study should provide some comfort to clinicians that perform stellate ganglion blocks on patients with a history of heart failure. In chronically instrumented animals, left stellate ganglion block had minimal affect on cardiac function either before or after heart failure had been induced. However, caution should always be exercised in extrapolating animal data to humans. In this regard, the investigators point out that in healthy humans, an impairment of left ventricular relaxation can be seen after left stellate ganglion block. They further caution that patients with acute heart failure in whom the response to changes in sympathetic tone is maintained, may be more susceptible to the adverse effects of left stellate ganglion block on cardiac dynamics.