Frequency of Development of Atrial Fibrillation After Coronary Artery Bypass Grafting in Different Age Groups

artery bypass grafting (CABG) surgery with a Post-up to 32% after CABG reported incidence up to 32%. Objective: To determine the frequency of development of atrial �brillation after coronary artery bypass grafting surgery in different age groups. Methods: This was an observational prospective cross sectional study, conducted at department of cardiac surgery Dr Ruth.K.M.Pfau Civil Hospital Karachi. The sample size of 199 was calculated. All patients between the ages of 30-70years. Irrespective of gender, refer for CABG surgery was included in the study. Two groups were made on the basis of their age, group 1, 30-50 years and group 2, 51-70 years. Those patients who came for CABG along with valve replacement and or other concomitant surgery were not included in my study. Results: After data collection through Performa data analyzed on SPSS 17.0. As per results 20.1% individuals in the study developed atrial �brillation. Male to female ratio was 3: 1. In Group 1, 16.6% patients developed Atrial Fibrillation and in group 2 21.58% developed Atrial Fibrillation with p value of 0.85. Hypertension was a commonest co-morbid and present in 56.2% patients in this study. Conclusion: The study concluded that the frequency of development of atrial �brillation after CABG as 20.10 %. Patients with positive family history of coronary artery diseases and smokers have signi�cantly higher risk to develop atrial �brillation after surgery.

that during aortic cross clamp, the blood supply to atrial tissue is compromised resulting in increase in the sympathetic supply and prolonged in ammatory response, that may play a critical role in the occurrence of Atrial brillation after CABG [5,6].In most of the cases, AF subsides after CABG surgery without any medication.However, even though AF is not associated with complications, its management needs further medical and nursing time and their hospital stay is usually extended [7].Patients with recurrent atrial brillation had longer hospital stays and experienced greater infectious, renal and neurologic complications than those with single episodes [8].Published literature has quoted the frequency of development of postoperative AF as high as 32% [9].This is a fairly high frequency of any complication to be developed after CABG surgery.Another research shows the frequency of development of AF after CABG as low as 12.3%.One local study also showed frequency of atrial brillation 15.2% after CABG [10].As the literature is not clear about the frequency, the present study is undertaken to ll the gap in literature and access postoperative atrial brillation after coronary artery bypass grafting surgery in our population.That's why this study aimed to determine the frequency of development of atrial brillation after coronary artery bypass grafting surgery in different age groups.the patients.They were subsequently underwent coronary artery bypass grafting surgery.After surgery, patients were followed for four days for nal outcome.The data along with demographic variables (age, gender, ethnic group) has been collected from the patients and mentioned in Performa.Risk factors included in Performa i.e. diabetes, HTN and smoking.Routine investigation, complete blood picture, BUN, Creatinine, electrolyte will be sent before and after surgery.Patients were observed postoperatively in the ICU for four days from the day of surgery as per standard protocol.

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The Study Design was Observational Prospective Cross Sectional study conducted at Department of Cardiac Surgery, Dr. Ruth K. M. Pfau Civil Hospital Karachi from January 2018 to January 2019.Through open EPI sample size was calculated and considering 15.2% proportion of atrial brillation as literature and margin of error 8%, con dence interval 95% sample size came out to be 199 patients.Patients with age of 30 to 70 years, either male or female and of any ethnic group who have recently undergone isolated coronary artery bypass grafting surgery with normal serum potassium levels (4.5-5.5mEq/L)wereincluded in this study and patients with chronic atrial brillation or atrial utter before surgery, Redo CABG,CABG with ischemic Mitral Regurgitation, CABG with Ventricular Septal rupture repair, Critical conducting disturbance preoperatively, Intraoperative death during hospital stay were excluded.Data collected through Non probability, consecutive sampling method using a Performa.Approval from the institutional ethical review committee and synopsis approval from DUHS has been taken.We included all patients meeting the inclusion criteria.Admitted patients enrolled from the cardiac surgery after formal written informed consent both in English and Urdu languages obtained preoperatively from

M E T H O D S
There were one hundred and ninety-nine patients underwent coronary artery bypass grafting surgery with normal serum potassium levels (4.5-5.5mEq/L) were included in this study.Patients were categorized into two different groups based on their age, rst group (included patients age between 30-50 years) 30.15%, second group (included age between 51-70 years) 69.85% patients participated in this study.Out of 199 patients, 150 (75.376%) were male and 49(24.623%)were female.Out 199 patients 76 (38.19%) were with EF more than 50%, 63 (31.7%) were with EF between 30-50% and less than 30 % EF were present in 60 (30.15%) patients.AF found more (31.5%) in patients with good EF as presented in Figure 1.Re g a rd i n g co -m o r b i d i t y, H y p e r te n s i o n wa s t h e commonest co-morbid that was observed in 56.2% cases, followed by diabetes mellitus 53.2%, Smoker 36.6% and family history of CAD was 26.6% as presented in Table 1.Mathew et al. [10,19].Some studies also shown age is not an independent factor, [20,21] for the development of AF.Although in elderly patients, its incidence is high which is concordant to Spodick DH et al study [21].In our study most of the patient belong to group 2 (51-70 years).Several researchers have found an increased incidence among males, [10][11][12]22] whereas others have reported no difference [23,24].Data derived from a research conducted by M Golmohammadi1 et al in Iran from 2006-2008 [25] and Auer et al. [21] did not support that male patients have more incidence of AF.In our study, Out of 199 patients, 75.37% were male and 24.63% were female, we did not nd any difference on univariate analysis, but on multivariate analysis male gender was the only factor for development of AF after CABG.In our study, Hypertension was the commonest comorbidity in 56.2% cases, but the incidence of AF did not reach to signi cant level.Although, the study of Ananke and colleagues [11] demonstrates that hypertension is the predictor of AF in the post CABG population.In our study, frequency of development of post CABG Atrial brillation was observed in 20.10% (40/199), while a similar study by M Golmohammadi et al [25] concluded that 12.3% of patients developed post CABG AF which is much less than our study.This could be due to difference in study design, population and criteria of assessment of AF in post CABG patients.

R E S U L T S
After CABG surgery "20% to 40% of patients developed Atrial Fibrillation (AF) [10][11][12].In spite of advancements in anesthetic and surgical techniques, no change has been noticed in the incidence of Arrhythmias in majority of cases post CABG Atrial brillation is self-limiting [10].Despite general decline in complications due to advances in surgery, there is no reduction seen in the development of postoperative atrial brillation.The incidence of AF is increasing because of the increasing age of patients underwent CABG [10,12].Although it is considered a benign complication but it may result in higher morbidity including We concluded in this study that the frequency of development of Atrial Fibrillation after CABG was found to be 20.10 %.Patients with positive family history of Similarly Frequency of development of post CABG atrial brillation was also not signi cant between male and female (Chi-Square = 1.2; p=0.27) in Table 2.With respect to co-morbidity, rate of development of post CABG atrial brillation was signi cantly high in smokers and those having positive family history.Hypertension, diabetes mellitus and dyslipidemia has been found statistically nonsigni cant.

Figure 1 :
Figure 1: Frequency of Atrial Fibrillation with respect to Ejection Fraction

Table 1 :
Comorbidity status of the patients (n=199) After CABG surgery there will be tissue remodeling in cardiac tissue that leads to brosis and scaring which increases the risk of development of AF.Advanced age is an independent risk factor in development of post-operative AF as shown in one of the study[12].Increased in atrial connective tissue is one of the factors for the development of AF at the age of eighty years as shown by

Table 2 :
Development of post CABG atrial brillation with respect to age & gender

Khahro AA et al.,
Frequency of Development of Atrial Fibrillation