Unilateral stellate block in the treatment of hypertension after coronary bypass surgery. Implications of a new therapeutic approach.

Unilateral stellate ganglion block (right or left) was achieved by local injection of 15 ml of lidocaine in 27 patients with hypertension after coronary bypass surgery. The stellate block led to rapid and sustained control of blood pressure in 18 patients (9 of 15 with right stellate block and 9 of 12 with left stellate block). The reduction in arterial pressure was associated with significant (P less than 0.01) reductions in total peripheral resistance and heart rate but no significant changes in cardiac output or central venous or left atrial pressures. This hemodynamic pattern as well as effectiveness of a unilateral approach suggests that the stellate block reduced arterial pressure by interrupting the afferent limb of a pressor reflex from the heart or great vessels, or both. The procedure was free from side effects and helped avoid prolonged parenteral administration of potent antihypertensive drugs.