HEART FAILURE;

CO-RELATION OF QRS DURATION WITH ATRIAL FIBRILLATION IN PATIENTS WITH REDUCED EJECTION FRACTION

Abstract

Introduction: Atrial fibrillation (AF) and wider QRS duration have long been
identified to worsen heart failure and LV dysfunction and increase cardiovascular morbidity
and mortality. Therefore, it is necessary to identify those patients of heart failure who are at
greater risk for cardiovascular morbidity and mortality so that such subjects may be focused
for preventive strategies. An association exists between QRS duration and AF with greater
incidences of cardiovascular events in patients of heart failure with LV systolic dysfunction.
Study Design: Cross sectional survey. Setting: Department of Cardiology, Punjab Institute of
Cardiology Lahore. Period: 16-02-2015 to 15-08-2015. Material and Methods: The objective
of study was to determine the Frequency of QRS Duration groups and Atrial Fibrillation in
Patients with Left Ventricular Dysfunction. Sample size of 400 cases was calculated with 95%
confidence level, 4% margin of error and taking expected percentage of atrial fibrillation in
narrow QRS group i.e. 20.9% (least among all) in patients with left ventricular dysfunction.
Sampling technique was non-probability, purposive sampling. Result: The study population
consisted of male (72.3%) and female (27.7%). Mean LA diameter was 40.3±6.08 mm and
mean LV ejection fraction 31.8±6.6 % in the study population. Ischemic heart disease was
the most common cause of LV dysfunction (88.3%) followed by non-ischemic cardiomyopathy
(8.75%) and non-Ischemic valvular heart disease (3.5%). The frequency of Narrow QRSd (<120
ms) was 62%, Intermediate QRSd (120-150 ms) was 26.5% and Wide QRSd (>150 ms) was
11.5%. The frequency of atrial fibrillation in study population was 15.75%. The frequency of atrial
fibrillation was highest in Wide QRSd group (>150 ms) i.e. (60.9%), followed by Intermediate
QRSd group (120-150 ms) i.e. (18.9%) and narrow QRSd group (<120 ms) i.e. (6.04%). Patient
with atrial fibrillation were more likely to have poor ejection fraction (P<0.0023) and wider QRS
duration (P<0.0001). Frequency of atrial fibrillation was highest in Valvular Cardiomyopathy
(non-ischemic valvular heart disease) patients (42.8%) as compared to coronary artery disease
group (15.3%) and non-ischemic cardimyopathy group (9.4%). Conclusion: In patients of heart
failure with reduced ejection fraction (HFrEF), the frequency of atrial fibrillation increases as
QRS duration widens. This group of patients must be focused for AF preventive strategies.