AUTHOR=Bonilla Ingrid M. , Nishijima Yoshinori , Vargas-Pinto Pedro , Baine Stephen H. , Sridhar Arun , Li Chun , Billman George E. , Carnes Cynthia A. 

TITLE=Chronic Omega-3 Polyunsaturated Fatty Acid Treatment Variably Affects Cellular Repolarization in a Healed Post-MI Arrhythmia Model

JOURNAL=Frontiers in Physiology

VOLUME=Volume 7 - 2016

YEAR=2016

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2016.00225

DOI=10.3389/fphys.2016.00225

ISSN=1664-042X

ABSTRACT=Introduction: Over the last 40 years omega-3 polyunsaturated fatty acids (PUFAs) have been shown to be anti-arrhythmic or pro-arrhythmic depending on the method and duration of administration and model studied. We previously reported that omega-3 PUFAs do not confer anti-arrhythmic properties and are pro-arrhythmic in canine model of sudden cardiac death. Here we evaluated the effects of chronic omega-3 PUFA treatment in post- MI animals susceptible (VF+) or resistant (VF-) to ventricular tachyarrhythmias.
Methods:  Perforated patch clamp techniques were used to measure cardiomyocyte action potential durations at 50 and 90% repolarization and short term variability of repolarization.  The early repolarizing transient outward potassium current Ito was also studied. 
Results Omega-3 PUFAs prolonged the action potential in VF- myocytes at both 50% and 90% repolarization. Short term variability of repolarization was increased in both untreated and treated VF- myocytes vs. controls. Ito was unaffected by omega-3 PUFA treatment. Omega-3 PUFA treatment attenuated the action potential prolongation in VF+ myocytes, but did not return repolarization to control values. 
Conclusions:  Omega-3 PUFAs do not confer anti-arrhythmic properties in the setting of healed myocardial infarction in a canine model of sudden cardiac death. In canines previously resistant to ventricular fibrillation (VF-), omega-3 PUFA treatment prolonged the action potential in VF- myocytes and may contribute to pro-arrhythmic responses.