Background and Objectives: Coronary artery bypass grafting (CABG) is usually performed through cardiopulmonary bypass (CPB). CPB, However, has been associated with several adverse effects. Recently, off-Pump CABG technique is offered as an alternative to the standard on-Pump CABG technique. The purpose of this study was to evaluate the safety of the off-Pump technique by estimating serum enzymes e.g. Creatin Kinase (CK), CK-MB, Lactate dehydrogenase (LDH), Aspartate Transaminase (AST), measurement of cardiac troponin I and some postoperative complications.Materials and Methods: Ninety patients (75 males and 15 females) with angiographically defined CAD admitted to Shahid Madani Heart Hospital in Tabriz for coronary artery bypass grafting were selected. The off-Pump technique was performed in 50 patients with mean age of 58‏. In 40 other patients with mean age of 56, the on-Pump technique was applied. The blood samples were collected from the patients before, 6, 12 and 24 hours after the operation. The activities of CK, CK-MB, LDH, AST in all serum samples were measured by Cobas Mira autoanalyser, and cardiac troponin I concentration also was measured by Evernest model 3200 motion. Data regarding patient age, sex, familial history of cardiovascular diseases, number of vessels grafted, procedural time, transfusion of blood and blood pressure were recorded for the both groups of patients. Postoperative data regarding the incidence of complications including myocardial infarction, need for inotrop adminstration and death were also recorded.Results: In this study the activities of serum enzymes such as CK, CK-MB, LDH and AST after on-Pump CABG technique were higher than those of off-Pump technique (P< 0.05 in all cases). The levels of troponin I were significantly higher after on-Pump CABG throughout the entire measurement period (P<0.01) compared with off-Pump procedure. In both groups of patients no myocardial infarction was occurred during operation. In the off-Pump technique procedural time was shorter and transfusion of blood was less than those of on-Pump technique, but no difference was noticed among the other recorded data.Conclusion: Significant reduction in the release of enzymes and troponin I during operation by off-Pump technique suggests that the technique causes less myocardial injury. On the basis of little changes in the activities of cardiac enzymes and troponin I in serum and presented data including a marked decrease in blood transfusion and shorter procedural time, it is concluded that off-Pump CABG is a safe and effective technique in selected patients with appropriate coronary lesions.

Background- Neurocognitive dysfunction after cardiac surgery with cardiopulmonary bypass (CPB or “Pump”) is a common complication, reported in up to 53% of patients. In many patients this morbidity is only mild and transient, but in 5% of cases, it is severe.Method-In this prospective study from June 2002 to July 2004,186 cases underwent coronary artery bypass graft surgery (CABG) using CPB or off-Pump CABG (OPCAB), and they were evaluated for neurocognitive complications by mini-mental status examination.Results- The average age of the patients was 56±6.2 years, 62% were male and 38% were female. 121 operations were performed with CPB (on-Pump) and 65 operations were done off-Pump. Mini-mental status test was normal in 50% of off-Pump CABGs and in 43% of on-Pump CABGs, very mild disturbance was seen in 48% of off-Pump CABGs and in 54% of on-Pump CABGs (p value=0.192, NS), mild disturbance was seen in 2% of off-Pump CABGs and in 3% of on-Pump CABGs (p value 0.392, NS), and moderate or severe disturbance was not seen in either group.Conclusion- In our study, there was no significance difference in the frequency of postoperative neurocognitive complications between off-Pump and on-Pump CABG patients.

Background: Studies that have specifically compared arrest and beating methods in on-Pump coronary artery bypass grafting (CABG) are limited. Objectives: In light of the aforementioned issues, the present study aimed to compare the results of two techniques of on-Pump arrest CABG and on-Pump beating CABG with the same surgical and anesthesiology team and the same protocol in a single center. Methods: In this retrospective cohort study that was conducted in Ghaem Hospital of Mashhad between November 2020 and 2022, the needed data were extracted from the medical records of all patients that underwent on-Pump beating CABG or on-Pump arrest CABG. According to the method of operation, other variables, including post-operation bleeding, atrial and ventricular arrhythmia, returning the patient to the operating room for bleeding, need for inotrope, need for a balloon Pump, hospital mortality, superficial and deep sternal infection and dehiscence, kidney injury, delayed extubation, length of hospital and intensive care unit (ICU) stay, and neurological complications were compared in the two groups. Results: A total of 105 patients with a mean age of 61.07±10.55 years were included in the study. Of these, 65 (61.9%) cases were male and the rest were female. Of the total patients included in the study, 60 subjects were in the beating group, and 45 cases were allocated to the arrest group. The postoperative outcomes were compared, and there was no significant difference between the two groups in terms of patients' outcomes (P>0.05). Furthermore, the comparison of in-hospital and one-month mortality of patients in two groups demonstrated no significant difference between the two groups (P>0.05). Conclusion: As evidenced by the obtained results, postoperative complications, as well as in-hospital and one-month mortality, are not significantly different between on-Pump arrest CABG and on-Pump beating CABG.

According to disadvantages and complications of cardiopulmonary bypass (CPB), cardiothoracic surgeons in world- wide have become interested in off-Pump CABG. Generally, coronary artery surgery accomplished in two Method, first routine method, in which CABG is performed with the help of CPB (Pump MACHINE). In this method, the field of the operation is motionless and free of blood, however the complications of the CPB are still present. Second off- Pump method that surgery is performed without using CPB. In this method, the heart is beating during operation, and normal activities of heart and lung are maintained, this method devoid of the disadvantages of the previous one.The first CABG surgery was done on a beating heart in 1960. In Iran cardiac surgery has commenced since 40 years ago, and is developing rapidly, but about operations with off-Pump Method and results, there is no documented study. Off-Pump CABG not only avoids of disadvantages of CPB but also has economic benefits. The goal of our study was to investigation the results (Ghaem, Javad-al-aemeh, Mosa-ebne-jafar Hospitals) in Mashhad, so that it can be a useful guide for future cardio-thoracic surgeons.

The present study was undertaken to compare the in hospital results of coronary artery bypass graft (CABG) with (on Pump) or without (off Pump) cardiopulmonary bypass (CPB). Data were collected on all first-time isolated CABGs with saphenous vein and/or artery grafts at Shahid Madani Hospital in Tabriz- Iran, between 2006 and 2009. Age and clinical profile were marched between on Pump and off Pump group patients. Patients with concomitant cardiac operations or beating Pump technique were excluded from the study. The study included 994 patients; CABG with CPB (ONCABG) was done in 578 (58%) and CABG without CPB (OPCABG) in 416 (42%). For Pump and off Pump group respectively, mortality rate was 2/3%, and 0.2%, the number of grafts was 2/92 ± 0.82 and 2/12 ±o.73 and the use of intra aortic balloon-Pump (IABP) was1.5% and5.4%. Post operative ejection fraction (EF) was improved in off Pump group (47.9±0.6) versus on Pump group (44.53±1.5) and the latter group had more post operative atrial fibrillation, Stroke, acute renal failure, bleeding rate and blood products transfusion, prolonged intubation time but was not statistically significance. Meanwhile Hospitalization time and use of inotrops was less in comparison with former patients group. Off Pump CABG was a safe method in our series. Patients with comparable risk profiles have similar prevalence's of selected complications after ONCABG and OPCABG, though some clinical and hemodynamic results are better with off Pump technique.

Background - Atrial fibrillation (AF) is the most common postoperative arrhythmic complication after coronary artery bypass graft surgery (CABG). The aim of the present study was to compare AF prevalence after off-Pump versus on-Pump CABG.Methods- In this prospective study, performed between September 2008 and September 2009, 128 consecutive patients in our local cardiovascular surgery ward were allocated into two groups of off-Pump (95 patients) and on-Pump CABG (33 cases).We compared preoperative risk factors such as left ventricular ejection fraction (LVEF)<%40, hypertension (HTN), and Cr>2mg/dl, site of grafting such as the left coronary descending artery (LAD), right coronary artery (RCA), and left circumflex artery (LCX) in the two groups of surgery techniques (on-Pump versus off-Pump CABG) with/without postoperative AF after 24 hours of surgery in the Intensive Care Unit. Statistical power of the study was 80%, and a P-value less than 0.05 was considered significant.Results - The prevalence of AF was 15 (15.8%) in the off-Pump group versus 7 (21.2%) in the on-Pump group (p=0.67) 24 hours after CABG. In the on-Pump group, there was no difference between age categories (p=0.11). In the on-Pump group, as opposed to the off-Pump CABG group, there was no relationship between the surgery techniques with or without AF, LVEF<%40, and HTN. There was a significant relation with Cr more than 2 mg/dl in the on-Pump CABG group (p=0.001) versus the off-Pump CABG group (p=0.057).There was no statistical relation between the type of vascular graft (LAD, RCA, and LCX) between the on-Pump and off-Pump CABG patients attributed to with or without AF.Conclusion - There was no reduction in the AF rate in the on-Pump CABG versus off-Pump CABG. It seems that there was another predictive factor for AF in the off and on-Pump CABG groups, so further prospective trials with larger sample sizes are recommended.

The use of Pumps linked in parallel or series in large scale pipe systems is usually inevitable, to meet the required head and discharge. Transient flow occurs following a Pump failure in a Pump group as a result of variations in the flow rate. This research is an investigation about waterhammer caused by one or more Pump-switch off in a Pump group when they are connected in parallel. The operation of each Pump in the group during steady and unsteady state is analyzed. For this purpose, the fluid flow equations as well as the Pumps relations including rotational speed change and head loss are combined and simultaneously solved in the time domain by the method of characteristic. From the results one can quantitatively conceive that the intermittent shut-down compared to suddenly switching off the whole Pump group produces much less waterhammer pressures. Furthermore in the intermittent shut-down with different Pump characteristics, it is suggested to firstly switch off the most powerful Pump, and then the rest which are weaker. Appropriate interpretation about the transition results have been included.