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Caffeine and Atrial Fibrillation
You may not realize it, but your heart is an electrical system. Each beat of your heart is started by an electrical pulse of what is called the sinus node, which is in the upper part of the right atrium (the top section of your heart, towards your right side). In normal sinus rhythm, the sinus node sends electrical impulses to the two upper chambers of your heart, the atria, and they then contract, or beat, simultaneously.
Coffee and Diabetes Risk
Researchers in Iowa recently conducted a study of 28,812 post-menopausal women to assess the impact of coffee drinking on their risk of developing diabetes (Arch Intern Med. 2006;166:1311-1316).
Steady your heart with omega-3 fatty acids
Heart rate variability - an inconstant heartbeat - is a known predictor of sudden death for heart disease patients. If consumption of omega-3 fatty acids through eating fish or through fish oil supplements will help regulate one's heart rate, and it can also help reduce your risk of sudden death through heart-related factors, it's reasonable to theorize that those fatty acids might well help regulate one's heart rhythm and reduce your risk of sudden death.
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Atrial fibrillation, or a-fib as it is often called, is essentially an irregular heartbeat. Instead of the electrical impulses governing the heart beat traveling through the heart in an orderly way, the impulses get disorganized, resulting in symptoms that range from imperceptible to feelings of the heart pounding or fluttering, or dizziness, chest pain, or shortness of breath. While age is a strong factor in developing a-fib, overweight and obesity are also considered to be contributors, as obesity is known to affect the heart by causing such physical problems as enlargement of the atria (the upper chambers of the heart) and diastolic dysfunction (problems with the left ventricle's function during diastole, or the moment between contractions when the ventricle is filling with blood).
While we know that the symptoms can be managed using medications (or even, in serious cases, with surgery), these medications can have serious side effects. A team of Australian researchers recently published an article in JAMA (2013;310(19):2050-2060) that sought to find out if weight loss alone could affect the frequency and severity of a-fib symptoms.
To find out, they designed a research study to compare the standard a-fib treatment with the standard a-fib treatment plus weight loss. The advantage of these types of studies is that all of the participants receive what is known to be the most effective treatment: nobody is left without any treatment at all.
The researchers recruited 150 men and women (mostly men) who had been diagnosed with atrial fibrillation, had a Body Mass Index over 27 (clinically overweight), were between 21 and 75 years of age, were not trying to lose weight, and did not have insulin-dependent diabetes. They were randomly assigned to one of two groups as mentioned above: standard of care consisting of intensive management of risk factors (including treatment for high blood pressure, glucose intolerance, poor cholesterol scores, sleep apnea, and alcohol and tobacco use), or standard of care plus a weight loss program.
The weight loss program began with 8 weeks of a very low calorie diet plan involving twice-a-day liquid meal replacements along with one high-quality meal high in animal or plant proteins and a low overall glycemic index. In addition the participants were directed to walk or bicycle for 20 minutes three times per week, increasing later to 45 minutes three times per week. After the 8 weeks the weight loss participants were transitioned to a weight maintenance program.
Throughout the 12 months (on average) of follow-up for both groups, the participants responded every three months to standardized questionnaires assessing their perception of the symptoms, duration, and severity of their atrial fibrillation. Further, at the start of the study and after 12 months each participant was subjected to a transthoracic echocardiogram to assess their heart's left atrium and the left ventricular wall's thickness (both affected by atrial fibrillation and used to assess severity and progression of the condition).
While symptom severity did not change in the first three months of the study for either group, after the first 6 months the weight loss group reported fewer and less severe symptoms than the control group. More importantly, changes in the heart's structure progressed more slowly in the weight loss group than in the control group, while their blood pressures and cholesterol scores improved more than those in the control group.
The design of this study, comparing standard of care to standard of care plus weight loss, makes it highly likely that the results of this study are due to weight loss and not some other factor. If you have atrial fibrillation and are currently overweight, talk to your doctor about whether losing weight would help improve your symptoms. She will want to monitor your progress carefully, especially if you are taking warfarin, so a visit to a dietitian may be in order.
First posted: November 20, 2013