Left stellate ganglion block has only small effects on left ventricular function in awake dogs before and after induction of heart failure

Left stellate ganglion block (LSGB) results in acute sympathetic denervatio n of the left ventricular (LV) posterobasal wall. We investigated the effec ts of LSGB in chronically instrumented awake dogs before and after the indu ction of pacing-induced congestive heart failure. Twelve dogs were instrume nted for measurement of global hemodynamics [LV pressure (LVP)], its first derivative (dP/dt), cardiac output (CO), and regional myocardial function ( systolic posterobasal segment length shortening, mean velocity [SLmv]). Bef ore the induction of heart failure (n = 12), LSGB did not affect CO [3.2 +/ - 1.4 (control, mean +/- SD) vs 3.3 +/- 1.6 L/min (LSGB, P = 0.45)] and SLm v (11.1 +/- 4.0 vs 10.8 +/- 4.0 mm/s, P = 0.16), but slightly reduced LVP ( 130 +/- 12 vs 125 +/- 14 mm Hg, P = 0.04), dP/dt(max) (3614 +/- 755 vs 3259 +/- 644 mm Hg/s, P = 0.003) and dP/dt(min) (-3153 +/- 663 vs -2970 +/- 725 mm Hg/s, P = 0.03). During heart failure (n = 8), global hemodynamics [CO (2.8 +/- 1.2 vs 2.7 +/- 1.2 L/min, P = 0.04), LVP (119 +/- 6 vs 112 +/- 9 m m Hg, P = 0.01), dP/dt(max) (1945 +/- 520 vs 1824 +/- 554 mm Hg/s, P = 0.03 ) and dP/dt(min) (-2402 +/- 678 vs -2243 +/- 683 mm Hg/s, P = 0.04)], as we ll as regional myocardial function, were significantly different after LSGB [SLmv] (8.0 +/- 3.8 vs 6.9 +/- 3.4 mm/s, P = 0.02)]. in conclusion, even d uring heart failure, the hemodynamic changes after LSGB are small, confirmi ng its broad margin of safety.