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Clinical and Surgical
Predictors of early post operative Atrial Fibrillation and Sustained
ventricular Tachycardia after cardiac surgery
Samia Sharaf Eldein(1), Ibrahim M. Yassin(2),
Reda S. Abd ElRhaman(3), Abeer Shahba(4) & Elsayed
M. Elmistekawy(2)
Departments of cardiology(1), cardiothoracic
surgery(2), anesthesia(3) &
internal medicine(4), faculty of medicine Tanta
University, Egypt
Tanta Med. Sc. J 2008; 3(4):96-106
Article type: Original article
Background/Aim: Post operative Atrial Fibrillation (AF). Occurs up
to 50% in cardiac surgery patients and represent the most common
post operative complication. Although malignant ventricular
tachycardia (V.T.) is uncommon arrhythmic complication early after
cardiac surgery - it has a negative impact on mortality. The
etiology of these arrhythmias (AF, V.T.) after open heart surgery is
incompletely understood and their prevention remains suboptimal.
Identification of patients vulnerable for post operative (AF, V.T.)
would allow targeting of these patients to benefit from aggressive
prophylactic intervention. The aim of this work is to evaluate the
incidence and identify risk factors of (AF, sustained V.T.) early
postoperatively after cardiac surgery. Methods and patients: 40
patients with a mean of age (55 + 10) years old (20 male, 20 female)
under went isolated elective cardiac surgery (20 patients for valve
replacement and 20 patients for CAPG). Demographic and clinical data
preoperative, operative and postoperative were collected. Patients
continuously monitored and hemodynamically significant (AF, VT) were
recorded. Detailed analysis was performed to define the risk
factors. Results: Post operatively AF occurred in (17/40) 42.5%. The
mean age for patients with postoperative AF. was 55 + 7.3 years old
compared with 47.7+9.3 years old for patients without AF P<0.05. The
mean heart rate variability (RMSSD) significantly differed between
patients with post operative AF and patients without (15 + 2.1 msec
VS 25 + 3 msec P<0.05. The mean of P wave dispersion for patients
with AF was significantly prolonged compared to patients without AF
(80 + 11 msec VS 42 + 12 msec, P<0.05). Multivariate logesitic
analysis (odds ratio + 95% CI, P value) was used to identify the
following independent predictors of post operative AF.: increasing
age above VS blow mean of age OR = 2.8 CI (1.2-3.5) P<0.01, valve
surgery VS CAPG OR= 2.75 CI (1.2- 3.2) P<0.05, preoperative non use
of beta blockers OR= 1.5 CI (1.1-4.2) P<0.05. Considering several
operative variables, use of internal mammary artery, pulmonary
venting, cardiopulmonary bypass time, and aortic cross clamping time
were significantly differed between group with AF. and group without
AF. [61.3% VS 85.7% P=0.001] [71.4% versus 28.6% P=0.001]. [113.8 +
33.5 m versus 92.4 + 36.3 m P=0.002]. [97.8 + 21.5, versus 71.3+ 9.3
P = 0.001 respectively. Only one patient developed sustained VT post
operatively (2.5%) of total study population, she was female had
longer pump time than patient without sustained VT (120 min VS 80 +
9.5 min P<0.05); longer Aortic cross clamping time (103 min VS 60 +
20 min P<0.05); had increased QTcD than patient without sustained VT
(120 msec VS 80 + 5 msec P<0.05). patients with and without
hemadynamicaly significant AF and sustained VT had similar body mass
index pre operative heart rate and preoperative blood pressure.
Conclusion: AF remains the most common complication after cardiac
surgery. Increasing age, type of surgery identifies patients at risk
for development of AF after cardiac surgery. Female sex, longer pump
time, aortic cross clamping time, are independent predictors of
developing sustained VT post operatively. Increased QTc dispersion,
decreased HRV (RMSSD) prolonged PWD after cardiac surgery may
reflect disrupted electrophysiological stability of the myocardium
and thus electrophysiological substrate for triggering malignant
arrhythmias.
ICID 881854 |