Arrhythmia

Also known as Dysrhythmia

An arrhythmia is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slowly, or with an irregular rhythm. When a heart beats too fast, the condition is called tachycardia. When a heart beats too slowly, the condition is called bradycardia.

Arrhythmia is caused by changes in heart tissue and activity or in the electrical signals that control your heartbeat. These changes can be caused by damage from disease, injury, or genetics. Often there are no symptoms, but some people feel an irregular heartbeat. You may feel faint or dizzy or have difficulty breathing.

The most common test used to diagnose an arrhythmia is an electrocardiogram (EKG or ECG). Your doctor will run other tests as needed. She or he may recommend medicines, placement of a device that can correct an irregular heartbeat, or surgery to repair nerves that are overstimulating the heart. If arrhythmia is left untreated, the heart may not be able to pump enough blood to the body. This can damage the heart, the brain, or other organs.

Explore this Health Topic to learn more about arrhythmia, our role in research and clinical trials to improve health, and where to find more information.

Arial Fibrillation

A Word on Atrial Fibrillation

Minimal research has been performed to determine if chocolate is tied to a decreased risk of atrial fibrillation, which takes place when the heart's upper chamber beats irregularly. Just under three million individuals in the United States have atrial fibrillation. Its presence heightens the risk of blood clots and subsequent heart failure, strokes, and other complications.

Indulging in a small amount of chocolate each week may lower the risk for a serious and fairly common irregular heart rhythm. This finding stems from a new study conducted in Denmark. The study's findings were recently published in the journal Heart.

The Results

Those who consumed chocolate between one and three times per month were around 10% less likely to endure atrial fibrillation compared to those who consumed chocolate less than once per month. It is becoming increasingly clear that the moderate intake of chocolate is a component of a healthy diet. However, the study cannot determine that chocolate was completely responsible for preventing atrial fibrillation.

Why Chocolate Improves Human Heart Health

Consuming cocoa and foods containing cocoa might boost heart health due to the considerable number of flavanols. These are compounds that scientists believe have anti-oxidant, blood vessel-relaxing and anti-inflammatory properties. Prior studies have determined the consumption of chocolate is linked to improved measures of heart health and a reduced risk for specific conditions such as heart failure and heart attacks. Dark chocolate is especially helpful as it is chock-full of flavanols.

New Analysis

The above-referenced study involved data collected from more than 55,500 individuals in Denmark. These individuals were between 50 and 64 years of age when the study began. They provided information about their food consumption between 1993 and 1997. The research team then tied the diet data to Denmark's national health registries to determine which individuals were diagnosed with atrial fibrillation. Around 3,346 atrial fibrillation cases occurred across an average of 13.5 years.

Those who ate a single serving (one ounce) of chocolate each week were 17% less likely to endure atrial fibrillation by the study's end compared to those who consumed chocolate less than once per month. Those who consumed between two and six ounces each week were 20% less likely to endure atrial fibrillation. Those who consumed more than one ounce of chocolate per day were 16% less likely to have atrial fibrillation.

It is interesting to note that the largest risk reduction for women was linked to consuming a single serving of chocolate per week. The biggest reduction for men occurred when consuming two to six servings each week.

Caveats

The consumption of chocolate alone is not enough to improve heart health. Chocolate consumption must be combined with physical activity and a healthy diet. It is also important to avoid smoking. It is likely that a double-blind, completely randomized and controlled trial will occur in the future to determine the true efficacy of chocolate consumption to ward off atrial fibrillation. This trial would likely make use of quantified amounts of cocoa.

It is also important to note that the research team could not account for unmeasured variables such as sleep apnea or kidney disease that might affect the risk for atrial fibrillation. Furthermore, the research team did not have data on the type of chocolate the study participants consumed. Nor did the research team have information about the amount of flavanols in the chocolate consumed by study participants. It is also quite likely that dietary intake was altered across the 14 years in which data collection occurred.

Chocolate and prevention of atrial fibrillation: what is bad for the pancreas might be good for the atria?