studies suggest that off-pump coronary artery bypass surgery is associated with improved outcomes when compared to on-pump coronary artery bypass. many studies have shown that off-pump coronary bypass surgery reduces patient morbidity and mortality.

manipulation of the coronary arteries during cardiac surgery can stimulate the adjacent post-ganglionic sympathetic fibers and mimic stellate ganglion stimulation ,stellate ganglion block (SGB) can interrupt this reflex by decreasing the efferent cervical sympathetic outflows.

when adopting off-pump surgery , the cardiac surgery team must adopt new techniques to handle a beating heart and the variations in hemodynamics that can occur when performing this type of procedure the incidence rate of cardiac arrhythmia occurring during and after surgery is one of the major complication in open heart surgery. in addition , intraoperative hemodynamic disorders, caused by changes in plasma levels of epinephrine and norepinephrine after surgical stimulation , are some of challenges for patients undergoing off-pump coronary artery bypass surgery. hemodynamic disruption leads to myocardial ischemia, resulting in increased incidence of cardiovascular events and mortality.

stellate ganglion is formed by the fusion of inferior cervical and first thoracic sympathetic ganglia and is located behind the subclavian artery and anterior to the first rib. the inferior cervical cardiac nerves arise from the medial aspect of the stellate ganglia and provide the cardio-accelerator nerve fibers to the cardiac plexus. stellate ganglion stimulation augments peak systolic pressure, and the enhanced myocardial contractility is secondary to stimulation by postganglionic nerve fibers which traverse from stellate ganglion down the great vessels and along the coronary arteries into the myocardium.the blockage of inferior cervical cardiac nerves is responsible for the bradycardia seen following SGB. SGB has been shown to prevent and control perioperative hypertension induced by increased sympathetic activity.

Inclusion Criteria:

• patients undergoing elective off-pump coronary artery bypass grafting surgery
• patients with an ejection fraction of more than 50%
• creatinine level of less than 2.0 mg / 100 ml
• no evidence of heart failure
• no significant chronic obstructive lung disease
• age of less than 60 years

Exclusion Criteria:

• emergency surgery
• patients on thrombolytic therapy
• patients with coagulation disorders
• patients requiring heart lung machine
• patients with clinical contraindications to SGB ( including allergy to local anesthetic , carotid vascular disease as defined by ipsilateral prior carotid endarterectomy or carotid stent, superficial infection at the proposed puncture site, contralateral phrenic or laryngeal nerve palsies , and severe chronic obstructive pulmonary disease )
• patients with history of atrial fibrillation