Atrial Fibrillation

Atrial fibrillation (AF) is an irregular and often rapid heart rate that can increase the risk of stroke, heart failure and other heart-related complications. During AF, the heart's two upper chambers (left & right atria) beat out of coordination with the two lower chambers (left & right ventricles) and symptoms often include heart palpitations, shortness of breath and weakness. AF may come and go (paroxysmal AF; PAF), or it can persist as a chronic condition. Although it is not immediately life-threatening, it is a serious medical condition that can sometimes require emergency treatment. AF can also lead to complications, such as the formation of blood clots which can block blood flow (ischemia). Treatments may include medications and other surgical interventions that aim to alter the heart's electrical conduction system.



Symptoms


Some patients with AF have no symptoms and are unaware of their condition until a physical examination takes place. 


Those who do have symptoms may experience:

  • Palpitations (sensations of a racing, uncomfortable, irregular heartbeat)
  • Weakness & Fatigue
  • Dizziness & Lightheadedness
  • Confusion
  • Shortness of breath
  • Chest pain


AF may be:


  • Occasional (PAF) → symptoms may last for a few minutes to hours and then stop on their own.


  • Persistent → the patient's heart rhythm doesn't go back to normal on its own and requires treatment such as an electrical shock or medications in order to restore heart rhythm.


  • Long-standing persistent → this type of AF is continuous and lasts longer than 12 months.


  • Permanent → the abnormal heart rhythm cannot be restored. The patient suffers from AF permanently and will often require medications to control their heart rate.



Causes


The heart consists of four chambers — two upper chambers (atria) and two lower chambers (ventricles). Within the right atrium is the sinoatrial (SA) node, the heart's innate pacemaker that produces the impulse that initiates each heartbeat. In atrial fibrillation, the atria experience chaotic electrical signals. The atrioventricular (AV) node — the electrical connection between the atria and the ventricles — is bombarded with impulses trying to reach the ventricles. The result is a fast and irregular heart rhythm. The heart rate of a patient with AF can range from 100 to 175 beats/minute. The normal range for a heart rate is 60 to 100 beats/minute.


Abnormalities or damage to the heart's structure are the most common cause of atrial fibrillation, for example:

  • High blood pressure
  • Heart attacks
  • Coronary artery disease
  • Abnormal heart valves
  • Congenital heart defects
  • Metabolic imbalance
  • Exposure to stimulants (eg. caffeine, tobacco or alcohol)
  • Sick sinus syndrome — improper functioning of the SA node
  • Lung diseases
  • Previous heart surgery
  • Viral infections
  • Stress due to pneumonia, surgery or other illnesses
  • Sleep apnea


Some patients with AF do not have any heart defects or damage, a condition called lone atrial fibrillation. In lone atrial fibrillation, the cause is often unclear, and serious complications are rare.



Risk Factors


Certain factors that may increase the risk of developing AF include age, existing heart disease, high blood pressure, alcohol consumption, obesity, family history, and other chronic conditions 



Minimally Invasive Treatment Options





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