atrial fibrillation is a common problem after cardiac surgery with
cardiopulmonary bypass. it is associated with increased morbidity, including
increased risk of stroke and need for additional treatment, with prolonged
hospital stay and increased cost. Numerous researchers have
examined potential risk factors for the development of postoperative atrial fibrillation
and advanced age and preoperative withdrawal of beta-blockers, are seems to be
the most common risk factors. if patients at high risk of developing post
atrail fibrillation could be identified, prophylactic efforts would be more
focused. AF is still very high although new development in surgical and new
anesthetic techniques, and post operative care and despite known higher risk,
post operative mortality and morbidity in patients with AF after CABG has
remained love even declined in recent years. Although there
is a general decline in complications the incidence of postoperative AF has
not decreased and actually appears to be increasing. Patho-physiologically,
the electric impulses degenerate in the upper chambers of heart (right and left
atrium) in organized rhythm into rapid disorganized pattern. It is also
considered that during aortic cross clamp time the blood supply to atrial
tissue is compromised that increased sympathetic supply that can be cause of AF
and prolonged inflammatory response may play a critical role in the development
postoperative AF. AF after CABG is self limiting in most
cases. However, even when AF is not complicated, its management needs further
medical and nursing time and atheir hospital stay extended.. patients with
recurrent atrial fibrillation had longer hospital stays and experienced greater
infectious renal and neurologic complications than those with single episode.
literature has quoted the frequency of development of postoperative AF as high
as 32%.4 This is 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%.5 One
local study conducted at Punjab that shows
frequency of atrial fibrillation 15.2%after CABG9. As there
is unclearity in literature, the
present study is undertaken to resolve
this issue and if it will be found lower , then coronary artery bypass grafting
surgery can be done safely with lowest risk of development of atrial
fibrillation after surgery.
To determine the
frequency of development of atrial fibrillation after coronary artery bypass
grafting surgery in different age group.
Artery Bypass Grafting: A surgical
procedure performed to restore normal blood circulation of blocked coronary
arteries(one or more than one) with conduit (artery or vein), bypassed the
obstructed blood vessel. These conduit usually harvested from the patient’s own arteries and veins located
in the leg, arm, or chest.
heart rhythm in which the atrial chambers of the heart, are out of sync with
the ventricles(upper and lower chamber of Heart doesn’t contract in rhythm) .
It is diagnosed as irregular rhythm with absence of p waves in ECG.
Study Design: Descriptive case series
Setting: Department of Cardiac Surgery, Dr. K.M.Pfau Civil Hospital,
Duration: 12 months after approval of
synopsis by committee.
Sample Size: The
frequency of development of atrial fibrillation after CABG, as reported in
previous studies showed wide disparity 32% and 12.3%. one local
study conducted at Punjab that shows frequency
of atrial fibrillation 15.2%after CABG. Considering it as a proportion of
atrial fibrillation, margin of error 8%, confidence interval 95% sample size
come out to be 199 patients.
Patients with age of 40 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 – 5.5
mEq/L) are included in this study.
Preoperative chronic atrial
fibrillation or atrial flutter
CABG with ischemic Mitral
CABG with Ventricular Septal
Preoperative critical conditions;
(advanced atrio-ventricular heart block or severe conduction disturbance)
intraoperative death during hospital stay.
Non probability, consecutive
will be collected using a Performa (Annexure 1). Approval from institutional
ethical review committee and synopsis approval from DUHS will be taken. We will
include all those patient meeting the
inclusion criteria. Admitted patients will be enrolled from the cardiac surgery
ward. After formal written informed consent both in English and Urdu
languages obtained preoperatively from the patients, they would subsequently
undergo coronary artery bypass grafting surgery. After surgery, patient will be
followed for four days for final outcome.
The data along with demographic
variables (age, gender, ethnic group) will be collected from the patients
and mention in Performa. Risk factors
included in Performa i.e. diabetes, HTN. Patients would be observed
postoperatively in the ICU for four days from the day of surgery as per
standard protocol. Patients will be divided into different three groups on the basis of their age, group
1 age below 30-50 years, group 2 age between 50-70 years.
Collected data will be entered and analyzed in SPSS 17.0.
Age will be analyzed in mean ± SD. Gender and presence of atrial fibrillatin
shall be analyzed in proportions and percentages. Results will be mentioned in
tables and graphs. Stratification with respect to age and gender will be done.
Post stratification chi square test will be applied. P value < 0.05 will be taken as significant.