Research by scientists at Harvard University shows that only fish cooked or grilled can increase the level of omega-3 fatty acids in the blood and reduce the incidence of arrhythmias. Fish processed by frying does not have the same effect. The study also found that eating fish at least once a week compared to once a month reduced the chance of atrial fibrillation by 30 percent. Atrial fibrillation is a type of arrhythmia and is closely related to stroke. Therefore, preventing atrial fibrillation can reduce the risk of stroke development. In one study, information on heart rate and other associated risk factors was analyzed in 169,871 adults ≥40 years of age, 93.4% of whom received a second survey. After a mean follow-up of about 8.3 years, a total of 6837 of the 108,534 individuals with complete heart rate and other related risk factors had an acute myocardial infarction, stroke, or died because of coronary heart disease and stroke. Of these, 3932 were men and 2905 were women. After multifactorial correction, it was found that those with heart rates ≥90 beats/min had a 32% increased risk of cardiovascular disease in men and a 23% increased risk in women compared to those with heart rates 60-74 beats/min. In addition, a heart rate ≥75 beats/min increased the risk of heart disease in men, and a heart rate ≥90 beats/min increased the risk of coronary heart disease and stroke in men and heart disease and coronary heart disease in women. Chronic arrhythmia may be a risk factor for cardiovascular disease in our adults and may be a major marker of cardiovascular disease. However, the risk of increased heart rate to human health and life is more insidious and should be given adequate attention by patients as well as clinicians. Arrhythmias are known to be very dangerous, as they can cause circulatory disorders in mild cases, sinus arrest, sinus block and bradycardia in more severe cases, and can lead to sudden death in severe cases.