Augmentation of cardiac sympathetic tone by percutaneous low‐level stellate ganglion stimulation in humans: a feasibility study

Modulation of human cardiac mechanical and electrophysiologic function by direct stellate ganglion stimulation has not been performed. Our aim was to assess the effect of low‐level left stellate ganglion ( LSG ) stimulation ( SGS ) on arrhythmias, hemodynamic, and cardiac electrophysiological indices. Patients undergoing ablation procedures for arrhythmias were recruited for SGS . A stimulating electrode was placed next to the LSG under fluoroscopy and ultrasound imaging; and SGS (5–10 Hz, 10–20 mA) was performed. We measured hemodynamic, intracardiac and ECG parameters, and activation recovery intervals ( ARI s) (surrogate for action potential duration) from a duodecapolar catheter in the right ventricular outflow tract. Five patients underwent SGS (3 males, 45 ± 20 years). Stimulating catheter placement was successful, and without complication in all patients. SGS did not change heart rate, but increased mean arterial blood pressure (78 ± 3 mmHg to 98 ± 5 mmHg, P  < 0.001) and dP /dt max (1148 ± 244 mmHg/sec to 1645 ± 493 mmHg/sec, P  = 0.03). SGS shortened mean ARI from 304 ± 23 msec to 283 ± 17 msec ( P  < 0.001), although one patient required parasympathetic blockade. Dispersion of repolarization ( DOR ) increased in four patients and decreased in one, consistent with animal models. QT interval, T‐wave duration and amplitude at baseline and with SGS were 415 ± 15 msec versus 399 ± 15 msec ( P  < 0.001); 201 ± 12 msec versus 230 ± 28 msec; and 0.2 ± 0.09 mV versus 0.22 ± 0.08 mV, respectively. At the level of SGS performed, no increase in arrhythmias was seen. Percutaneous low‐level SGS shortens ARI in the RVOT , and increases blood pressure and LV contractility. These observations demonstrate feasibility of percutaneous SGS in humans.