Efficacy of Ivabradine Versus Propranolol Premedication During Hypotensive Anesthesia in Endoscopic Sinus Surgery

50 Patients, aged from 18 to 39 years, ASA physical status I and II, undergoing endoscopic sinus surgery will be enrolled in the study.The patients will be randomly allocated by simple randomization using a computer programme into two groups by closed envelope technique (having 25 patients in each group): GROUP (P): will receive oral propranolol (INDERAL® -propranolol hydrochloride Ph. Eur. 10mg manufactured by AstraZeneca Egypt under license of AstraZeneca UK), 10 mg one tablet at 8:00 pm in the evening before the day of the surgery and one 10 mg tablet one hour before the induction of anesthesia. GROUP (I): will receive oral ivabradine (Procoralan® 5mg manufactured by Servier laboratories, France), 5 mg one tablet at 8:00 pm in the evening before the day of the surgery and one 5 mg tablet one hour before the induction of anesthesia.