Dietary Flaxseed Protects against Post‐Myocardial Infarction Arrhythmias and Injury

Dietary Ω‐3 polyunsaturated fatty acids (Ω‐3 PUFAs) have been associated with a lower incidence of cardiovascular events and sudden cardiac death. Flaxseed is one of the richest plant sources of Ω‐3 PUFAs and has been observed to retard the progression and accelerate the regression of atherosclerotic plaque. The aim of the study was to examine the effects of dietary flaxseed on heart function and arrhythmias that develop after a myocardial infarction (MI). The left anterior descending coronary artery was ligated in rats to induce the MI. Rats were randomized into five groups: sham MI with normal chow, MI with normal chow, MI with 10% milled flaxseed supplementation (flax), MI with 4.4% supplemented flax oil rich in alpha‐linolenic acid (ALA), and MI with flax lignan secoisolariciresinol diglucoside (SDG) supplementation (0.44%). Animals were fed with their respective diets for two weeks before and for 8 weeks after the surgery. Echocardiography and continuous ECG recordings were obtained after ligation to confirm the induction of the MI, to check for arrhythmias and to assess cardiac function. Histological examination was also performed to evaluate cardiac fibrosis. Dietary supplementation with flax, ALA, and SDG significantly reduced the incidence of arrhythmia. Hearts obtained from flax, ALA, and SDG supplemented animals exhibited the smallest infarct size (12.39±0.77%, 13.70±1.20%, 11.63±1.36% vs. 34.02±3.22%, p<0.001). The left ventricle in the flax group was significantly less dilated compared to the control group (6.41±0.22 mm vs. 8.26±0.28 mm, p<0.001). A significantly small percentage of myocardial fibrosis and levels of tumor necrosis factor‐α were observed in all flax groups compared to the MI group (p<0.001). Together, this study generates evidence for a beneficial effect of flaxseed in patients post MI for the prevention of arrhythmias and ventricular remodeling.Support or Funding InformationThis work was supported by AAFC, CIHR, SaskFlax, Western Grain Research Foundation, Pizzey's Ingredients and St Boniface Hospital Foundation.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.