• Antiarrhythmic drugs
• atrial arrhythmias
• cardiac arrhythmias
• cardiac remodelling
• omega-3 fatty acids
• sudden cardiac death

Omega-3 polyunsaturated fatty acids (PUFA), in particular the marine-derived forms eicosapentaenoic acid and docosahexaenoic acid, have been touted as natural, multipotent treatments for a wide variety of disease conditions. Interest in using these PUFA (found in marine algae and fatty cold water fish such as salmon, mackerel and tuna) to prevent and treat cardiovascular disease (CVD) has grown exponentially since it was first proposed in the 1970s. A series of studies published during that decade showed that Greenland ‘Eskimos’, despite subsisting on a diet containing a great deal of whale, seal and fish fat, had virtually no incidence of CVD. This led to the suggestion that the low CVD rates among Eskimos were the result of high PUFA intake and their putative antiatherogenic/antithrombotic effects.1 Since then, PUFA have been shown to have anti-inflammatory and antiplatelet properties, as well as the ability to lower blood pressure and triglycerides.1 Large studies carried out during the 1980s and 1990s in populations of patients with CVD and post-myocardial infarction (MI) showed that PUFA could also reduce mortality and possibly sudden death rates.1 Those studies were supported by basic science findings showing that PUFA can alter the electrophysiological properties of cardiac cells, perhaps by affecting membrane fluidity or ion channel function.2 There arose a perception that PUFA may be a sort of ‘antiarrhythmic drug’. Based on this evidence, the current American Heart Association guidelines recommend eating fish high in PUFA at least twice a week (http://www.heart.org).

Over the past decade, the focus of research on PUFA has expanded also to include atrial arrhythmias. This was based on the hypothesis that mechanisms of arrhythmogenesis are similar between atria and ventricle, and therefore putative antiarrhythmic effects of PUFA would be as evident in …