Atrial Fibrillation

What is AF?
Atrial fibrillation (AF or AFib), is the most common and one of the most undertreated heart rhythm disorders in America. The disease, which involves an irregular quivering or rapid heart rhythm in the upper chambers (atria) of the heart, is found in approximately 33 million people worldwide.

When the heart does not contract at a normal rhythm, blood is not pumped completely out of the atria and may pool and clot.

Why Treat AF?
When left untreated, AF patients have a five times higher chance of having a stroke, and are at greater risk of developing heart failure.

Additionally, since AF causes inefficient pumping of the heart, patients can develop symptoms such as palpitations, shortness of breath, chest tightness or lightheadedness.

Three Types of AF
Paroxysmal AF occurs when the rapid rhythm in the heart’s upper chambers start and stop suddenly, usually for minutes or days at a time.

Persistent AF occurs when the heart’s upper chambers beat erratically for more than seven days and medical intervention or drug therapy is needed to stop the episode.

Permanent or continuous AF occurs when the heart’s upper chambers consistently beat erratically, and a decision has been made by the patient and the doctor not to try to restore normal sinus rhythm by any means, including catheter or surgical ablation.

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Normal Sinus Rhythm
atrial fibrillation with abnormal electric pathways

Supraventricular Tachycardia (SVT)

Supraventricular tachycardia (SVT) is a general name for fast heart rhythm disorders that start in the top chambers of the heart.

It frequently occurs intermittently and can be difficult to diagnose.  Diagnosis can be made from an electrocardiogram, but due to it’s intermittent nature, a heart monitor is usually placed to record the heart rhythm.

SVT can cause significant symptoms, such as:

  • Palpitations, or heart fluttering
  • Shortness of breath
  • Lightheadedness and fainting
  • Chest tightness

Often catheter ablation is recommended as a potentially curative treatment.

Bradycardia (Slow Heart Rate)

Bradycardia is a heart rate that is too slow.

In general, for adults, a resting heart rate of fewer than 60 beats per minute (BPM) qualifies as bradycardia.  But there are exceptions. Your heart rate may fall below 60 BPM during deep sleep. Physically active adults (and athletes) often have a resting heart rate slower than 60 BPM.  Medications can also cause bradycardia.

Causes for bradycardia include:

  • Problems with the sinoatrial (SA) node, sometimes called the heart’s natural pacemaker
  • Problems in the conduction pathways of the heart that don’t allow electrical impulses to pass properly from the atria to the ventricles, resulting in electrical heart block
  • Metabolic problems such as hypothyroidism (low thyroid hormone)
  • Damage to the heart from heart disease or heart attack
  • Certain heart medications that can cause bradycardia as a side effect

Symptoms of bradycardia

  • Fatigue or feeling weak
  • Dizziness or lightheadedness
  • Fainting (or near-fainting) spells
  • Shortness of breath
  • Difficulty when exercising

Ventricular Tachycardia (VT)

Ventricular tachycardia is a fast heart rhythm which starts in the lower chambers of the heart, the ventricles. It causes the ventricles to contract before they have had a chance to completely fill with blood, impairing blood flow to the body.

Ventricular tachycardia often occurs in people with underlying heart abnormalities. In those who have had a heart attack, for example, the scar from the heart attack causes the electrical abnormalities that create the tachycardia.

This is a serious disorder and requires prompt treatment. It poses a serious danger in that it may evolve into the more serious ventricular fibrillation.  Ventricular fibrillation is the primary cause of sudden cardiac death. If normal rhythm is not restored within 3-5 minutes, the heart and brain will be damaged, and the patient will die.

Treatment of ventricular tachycardia includes medications and catheter ablation.  High-risk patients are treated with an implantable cardioverter-defibrillator (ICD). This device, which is inserted under the skin of the chest like a pacemaker, senses irregular rhythms and automatically shocks the heart back into normal rhythm.