Atrial Fibrillation (AFib)

  • Medical Author:
    Daniel Lee Kulick, MD, FACC, FSCAI

    Dr. Kulick received his undergraduate and medical degrees from the University of Southern California, School of Medicine. He performed his residency in internal medicine at the Harbor-University of California Los Angeles Medical Center and a fellowship in the section of cardiology at the Los Angeles County-University of Southern California Medical Center. He is board certified in Internal Medicine and Cardiology.

  • Medical Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

Quick GuideAtrial Fibrillation: Heart Symptoms, Diagnosis & Treatment for AFib

Atrial Fibrillation: Heart Symptoms, Diagnosis & Treatment for AFib

What is the normal function of the heart?

  • The heart has four chambers. (The upper two chambers are the atria, and the lower two chambers are the ventricles.)
    1. The right atrium (upper right)
    2. The left atrium (upper left)
    3. The right ventricle (lower right)
    4. The left ventricle (lower left)
  • Blood returning to the heart from the body contain low levels of oxygen and high levels of carbon dioxide. This blood flows into the right atrium and then down into the adjacent right ventricle.
  • After the right ventricle fills, contraction of the right atrium pumps additional blood into the right ventricle.
  • The right ventricle then contracts and pumps the blood to the lungs where the blood takes up oxygen and gives off carbon dioxide.
  • The blood then flows from the lungs to the left atrium, and then down into the adjacent left ventricle.
  • Contraction of the left atrium pumps additional blood into the left ventricle.
  • The left ventricle then contracts and pumps the blood to the rest of the body.
  • The heartbeat (pulse) that we feel is caused by the contraction of the ventricles.
  • The ventricles must deliver enough blood to the body for the body to function normally.
  • The amount of blood that is pumped depends on several factors. The most important factor is the rate of contraction of the heart (the heart rate).
  • As the heart rate increases, more blood is pumped.
  • The heart pumps more blood with each beat when the atria contract and fill the ventricles with additional blood just before the ventricles contract. Continue Reading
Reviewed on 7/13/2016
References
Medically reviewed by: Robert J. Bryg, MD; Board Certified Internal Medicine with subspecialty in Cardiovascular Disease.

REFERENCES:

UpToDate. Patient information: Atrial fibrillation (Beyond the Basics).

Wann, Samuel L., et al. "2011 ACCF/AHA/HRS focused update on the management of patients with atrial fibrillation (Updating the 2006 Guideline): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines." Journal of the American College of Cardiology 57.2 (2011): 223-242.

IMAGES:

1. Getty Images

2. MedicineNet

3. MedicineNet

4. MedicineNet

5. Getty Images

6. iStock

7. MedicineNet

8. Getty Images

9. Alex CM4000" by Misscurry - Template:Entwicklung

10. iStock

11. Getty Images

12. iStock

13. MedicineNet

14. MedicineNet

15. MedicineNet

16. iStock

17. MedicineNet

18. Getty Images

19. Blausen.com staff. "Blausen gallery 2014". Wikiversity Journal of Medicine. DOI:10.15347/wjm/2014.010. ISSN 20018762.

20. Getyy Images / iStock

21. MedicineNet

22. MedicineNet

Subscribe to MedicineNet's Heart Health Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

VIEW PATIENT COMMENTS
  • Atrial Fibrillation - Effective Treatments

    What kinds of treatments have been effective for your atrial fibrillation?

    Post View 23 Comments
  • Atrial Fibrillation - Symptoms and Signs

    What symptoms and signs did you experience with your atrial fibrillation?

    Post View 13 Comments
  • Atrial Fibrillation - Complications

    Describe the complications you've experienced with atrial fibrillation.

    Post View 4 Comments
  • Atrial Fibrillation - Medications

    What medications have you taken to treat atrial fibrillation?

    Post View 5 Comments
  • Atrial Fibrillation - Procedures

    Describe the procedures you've had to treat atrial fibrillation.

    Post View 3 Comments

Health Solutions From Our Sponsors