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

Abstract

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 (ARIs) (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.

Keywords: Activation recovery interval; arrhythmias; stellate ganglion; sympathetic stimulation.

Figure 1

Stimulation and Recording Electrode Set Up. (A) Antero-posterior (AP) fluoroscopic view of the lower cervical and upper thoracic region, depicting the approach and positioning of the introducer needle and StimuCath electrode for stellate ganglion stimulation. Prior to stimulation the introducer needle was removed and the stimulating electrode left in place. (B) Right and left anterior oblique fluoroscopic projections of the thorax, displaying the location of the high right atrial (RA), His bundle, right ventricular (RV), coronary sinus (CS), and right ventricular outflow tract catheters (RVOT). Unipolar electrograms were recorded with the RVOT catheter.

Figure 2

Hemodynamic and Electrophysiologic Response to Sympathetic Stimulation. (A) Representative electrocardiographic, electrogram, and hemodynamic responses to left stellate ganglion stimulation (SGS). (B) An example of ARI measurement from electrogram at baseline and following SGS. The bars on the QRS downslope and T-wave upslope reflect the interval measured as the ARI. (C) Quantifications of Systolic, diastolic, mean arterial, and pulse pressures at baseline and during sympathetic stimulation. dP/dt, a marker for cardiac contractility is also shown. ***P < 0.001. (D) Graphical quantification of atrio-ventricular nodal (A–H: atrio-His) and His-Purkinje (H–V: His-ventricle) conduction at baseline and following SGS (msec: milliseconds).

Figure 3

Changes in Activation Recovery Intervals with Stellate Ganglion Stimulation. (A) Individual responses to sympathetic stimulation, with and without atropine (atr) at baseline and during stellate ganglion stimulation. (B) Dispersion of repolarization (ARI_max–ARI_min) in each subject.

Figure 4

Electrocardiographic parameters during stellate ganglion stimulation. Shown are the mean responses across all subjects to stellate ganglion stimulation in QT interval, corrected QT interval (QTc); R-R interval, T-wave duration, T-wave amplitude in Leads II and V5, and Tpeak-Tend in Leads II and V5 (msec: milliseconds; mV: millivolts).