Arrhythmia Chapter 1

What are Arrhythmias? (VIDEO)

Your heart is electric. In this video you'll see how your heart's electrical system works, and what happens when it malfunctions. Voyage inside the human body as Dr. Mehmet Oz and others explain the dangers of heart arrhythmias, including tachycardia, bradycardia, and atrial fibrillation.

What Makes Your Heart Beat?

Your heart beats about 100,000 times a day, and every beat is a symphony. Each is a perfectly timed, carefully synchronized flow of electric current over a precise pathway on the heart's surface. This rhythmic flux literally wrings the blood out of the heart and pushes it through the 60,000 miles of arteries, capillaries, and veins that comprise your circulatory system. Arteries carry oxygen-rich blood away from the heart to the capillaries, where nutrients and oxygen flow out into the tissues. Veins collect the de-oxygenated blood from the capillaries and carry it back to the heart and lungs for replenishment. Read more

Blood's Pathway

Anatomy of the Heart
Your heart has four hollow chambers. The atria, which are smaller and less muscular, are at the top, and the ventricles are at the bottom. The right atrium and ventricle pump oxygen-depleted blood to the lungs, and the left atrium and ventricle pump newly oxygenated blood to the body. Read more

The Electric Heart

The Heartbeat
Each heartbeat starts with an electrical impulse from the sinoatrial node, a small group of cells in your right atrium. The impulse is carried by the Purkinje fibers, located in the inner ventricular walls of the heart. The electrical signal causes your right and left atria to contract and fills the relaxed ventricles with blood. The electrical impulse in a normal, healthy heart follows a precise pathway across the heart. From the sinoatrial node, it travels to the atrioventricular node at the center of your heart and from there to your ventricles, causing them to contract and discharge blood throughout your body. The cells then recharge (repolarize) in preparation for the next heartbeat. Read more

Symptoms of Arrhythmia

Symptoms of arrhythmia can range from completely asymptomatic (without symptoms) to loss of consciousness and cardiac sudden death. Severe symptoms are more likely to occur if structural heart disease is present. Read more

Heart Disease & Arrhythmia

Heart disease is a major cause of arrhythmia, due to lack of blood flow and heart tissue damage.

  • Coronary artery disease (CAD) restricts blood flow to the heart due to narrowed arteries. This can lead to heart tissue death myocardial infarction, or heart attack, and scarring.
  • Cardiomyopathy occurs when the ventricle walls stretch and enlarge (dilated cardiomyopathy) or when the left ventricle wall thickens and constricts (hypertrophic cardiomyopathy). This decreases the heart's ability to pump and often leads to heart tissue damage. Unlike other muscles in the body, the heart grows weaker, not stronger, as it becomes larger.

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Risk Factors

A number of factors may increase your risk of developing an arrhythmia, some of which you can control, and some of which you can't:

  • Age
  • Genetics (being born with a heart abnormality)
  • Heart disease
  • Smoking
  • High blood pressure
  • Obesity
  • Diabetes
  • Sleep apnea

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Testing & Diagnosis

In testing for an arrhythmia, the doctor may question the patient about conditions that trigger the arrhythmia. Arrhythmia-inducing tests may then be performed so that the arrhythmia can be diagnosed. Passive testing doesn't seek to trigger the arrhythmia, only to monitor the heart in its usual state. Read more

Resetting the Heart's Rhythm

Arrhythmia isn't necessarily treated. If the arrhythmia isn't causing significant symptoms or putting the patient at risk for a more serious condition, the arrhythmia may simply need to be monitored.

If the arrhythmia does produce serious symptoms or is life threatening, a number of treatment options are available. Read more

A Heart Healthy Lifestyle

Improving your health can lessen the symptoms of arrhythmia and other heart disorders. Underlying heart disease can increase the risk of developing arrhythmias. For these reasons, it makes sense to live a lifestyle that will keep your heart as healthy as possible. Read more

The material on this site is for informational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any medical condition. Consult a licensed medical professional for the diagnosis and treatment of all medical conditions and before starting a new diet or exercise program. If you have a medical emergency, call 911 immediately.