Cardiovascular Journal of Africa: Vol 30 No 3 (May/June 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 3, May/June 2019 174 AFRICA
Review Article
Remodelling in atrial fibrillation: the impact of
amiodarone
Alin Ionut Grosu, Dan Radulescu, Laura Cristina Grosu, Dana Pop
Abstract
Atrial fibrillation (AF) is a common heart rhythm disorder
with a prevalence of up to 2.9% in the general population.
Its mechanism involves a particular electrophysiological
profile as well as structural and biohumoral changes that are
often irreversible. With the recent advances in pharmacology,
amiodarone remains the cornerstone for the treatment of AF.
Although it is one of the most controversial anti-arrhythmic
agents due to the multitude of side effects, it is further recog-
nised as the most effective drug available for the conversion
and maintenance of sinus rhythm in the case of significant left
ventricular dysfunction or severe aortic stenosis. This quality
is provided by its multivalent profile, with a complex electro-
physiological activity overlapped with an anti-inflammatory
and vasodilatory effect. This review aims to outline the main
structural and functional changes in AF and the multisite
impact of amiodarone on its treatment.
Keywords: atrial fibrillation, inflammation, remodelling,
amiodarone, anti-arrhythmic
Submitted 12/12/18, accepted 26/2/19
Published online 27/3/19
Cardiovasc J Afr 2019; 30: 174–180
DOI: 10.5830/CVJA-2019-012
The prevalence of atrial fibrillation (AF) in the general population
is estimated to be around 0.5–1%. Some recent data indicate that
the condition has doubled in prevalence in the last decade among
European countries, with values of up to 2.9% in Sweden.1
Although the interventional approach for the treatment of
AF has had a great impact over the past two decades, the recent
CABANA study did not reveal any general differences in terms
of death, risk of stroke, haemorrhagic events or hospitalisation
time between patients undergoing ablation and those with anti-
arrhythmic drug therapy on an average of four years of follow
up. An improvement was observed in quality of life and in
people under the age of 65 years,2 and ablation proved beneficial
in patients with heart failure and left ventricular dysfunction.
The results were similar to those of the CASTLE-AF trial.3
Amiodarone (AM) is an iodinated benzofuran derivative,
developed in 1961 by a Belgian pharmaceutical company and
originally marketed in Europe and South Asia as an anti-
anginal agent due to its coronary vasodilator properties and
its capacity to reduce myocardial oxygen demand. Some years
later, in 1974, Mauricio Rosenbaum published the results of
a study demonstrating the efficacy of AM for the treatment
of supraventricular and ventricular arrhythmias.4 This article
opened up new horizons in cardiology practice, with AM
today being one of the most prescribed anti-arrhythmic drugs
worldwide, with more than three million annual prescriptions in
the USA.
Over the decades, the multiple effects of AM have been
reported. It possesses a complex electrophysiological profile,
induces modulation of the inflammatory cascade, and not
least, being a possible agent for reverse remodelling of the left
atrium. These characteristics have successfully placed AM on
top of the list as the most efficient anti-arrhythmic agent for
both conversion and rhythm-control strategy for AF. Its safety
profile recommends it as the only medication that can be used
for the maintenance of sinus rhythm in patients with severe
forms of systolic heart failure or aortic stenosis. This article
reviews important elements of the pathophysiology of AF and
the multilevel impact of AM on its treatment.
Electrical remodelling in AF
AF is characterised by chaotic atrial electrical activity, which
causes irregular and usually rapid ventricular contraction. It
is initiated when ectopic excitation encounters a pathological
substrate of AF. The left atrium and pulmonary veins in particular
are responsible for over 90% of cases of AF, the role played by
pulmonary veins being more important in the case of paroxysmal
AF. These contain muscular beams originating from the left
atrium with peace-maker ability, similar to cells in the sinus and
atrioventricular nodules. Subsequently, the electrical pulse passes
through the left atrium, with the generation of AF. In less than
Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-
Napoca, Romania
Alin Ionut Grosu, MD
Dan Radulescu, MD
Laura Cristina Grosu, MD
Dana Pop, MD
Cardiology Department, Municipal Clinical Hospital, Cluj-
Napoca, Romania
Alin Ionut Grosu, MD,
Dan Radulescu, MD
Cardiology-Rehabilitation Department, Clinical
Rehabilitation Hospital, Cluj-Napoca, Romania
Dana Pop, MD