الفهرس 
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Abstract
Perioperative cardiac complications are an important concern for the millions of individuals who undergo surgery worldwide every year. After surgery, 2% of these patients suffer major cardiac complications.
Non-cardiac surgery causes a rise in catecholamine concentrations that results in an increase in heart rate, blood pressure, and free fatty acid concentrations, which in turn increases myocardial oxygen demand.
The cardiovascular effects of general anesthesia include changes in the arterial and central venous pressures, cardiac output, and varying heart rhythms.
Every operation elicits a stress response. This response is initiated by tissue injury and mediated by neuroendocrine factors, and may induce tachycardia and hypertension. Fluid shifts in the perioperative period add to the surgical stress. This stress increases myocardial oxygen demand
A previously stable patient may decompensate postoperatively, leading to significant postoperative morbidity and mortality. A substantial number of all deaths among patients undergoing noncardiac surgery are caused by cardiovascular complications.
The high prevalence of cardiac events associated with noncardiac surgery reflects the high prevalence of underlying Coronary artery disease in the general population, upon which the additional stresses of surgery are overlaid
The pathophysiology of perioperative myocardial infarction is complex, but may include myocardial oxygen demand/supply mismatch associated with tachycardia, hypertension, and pain.
The main rationale for perioperative beta-blocker use is to decrease myocardial oxygen consumption by reducing heart rate, leading to a longer diastolic filling period and decreased myocardial contractility.
Aim to study the effects of perioperatively administered beta-blockers for prevention of surgery-related mortality and morbidity in patients undergoing major abdominal surgery while under general anesthesia
This is an observational prospective study, in which 240 patients were divided into 2 groups (120 patients each) as follows:
Beta blocker group (BB group) 120 patients on beta blocker (Bisoprolol 5 mg) started more than 15 days preoperative and continued for at least 7 days postoperative.
Control group: 120 patients not receiving any betablocker.
All patients were closely monitored for 7 days postoperative for the possible cardiovascular mortality and morbidity as Death (either cardiac or non cardiac), Non fatal myocardial infarction.,Acute stroke.,Arrhythmia., Heart failure. Significant hypotension (SBP < 100) and Significant bradycardia (HR < 45 bpm).
In this study, it was noticed that bradycardia with HR less than 45 bpm happened in 46 patients (38.3% of patients) in beta blocker group compared to 12 patients (10% of patients) in the control group.
Regarding the occurrence of arrhythmia either ventricular or supraventricular. It was found in the beta blocker group, that arrythmia occurred in 16 out of 120 patients representing 13.3% compared to the control group in which it occurred to 48 out of 120 patients representing 40% of the patients in the control group.
In this study, results showed no difference between 2 groups regarding cerebrovascular events and heart failure.
Equal cases of mortality happened to patients in both groups.
As regards hypothension with SBP<90 mmHg, we found that it occurred to 32 patients representing 26.7 % of beta blocker group, compared to 18 patients representing 15 % of the control group.
In conclusion, analysis of the results concluded that Patients on beta blocker are at less risk of perioperative arrhythmias and myocardial infarction when undergoing high risk surgeries. These patients are at higher risk of experiencing episodes of bradycardia and hypotension. No significant effect on perioperative heart failure, cerebrovascular stroke and mortality.