Premature Ventricular Contractions (PVCs)
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.
Dennis Lee, MD
Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
- What are premature ventricular contractions (PVCs)?
- What happens during a premature ventricular contraction?
- How common are premature ventricular contractions?
- What causes premature ventricular contractions?
- What are premature ventricular contraction symptoms?
- What are the dangers of premature ventricular contractions?
- How is premature ventricular contraction diagnosed?
- What are the treatments for premature ventricular contractions?
- Patient Comments: Premature Ventricular Contractions (PVCs) - Symptoms
- Patient Comments: Premature Ventricular Contractions (PVCs) - Causes
- Patient Comments: Premature Ventricular Contractions (PVCs) - Experience
- Patient Comments: Premature Ventricular Contractions (PVCs) - Treatment
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What are premature ventricular contractions (PVCs)?
Premature ventricular contractions (PVCs) are premature heartbeats originating from the ventricles of the heart. Premature ventricular contractions are premature because they occur before the regular heartbeat.
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.
- The atria deliver blood to the ventricles, and the ventricles deliver blood to the lungs and to the rest of the body.
- The right ventricle delivers blood to the lungs while the left ventricle delivers blood to the rest of the body.
- The heartbeat (pulse) that we feel is caused by the contraction of the ventricles.
The heartbeat is normally controlled by the electrical system of the heart. The electrical system of the heart consists of the sinoatrial (SA) node, the atrioventricular (AV) node and special tissues in the ventricles that conduct electricity.
The SA node is the heart's electrical pacemaker. It is a small patch of cells located in the wall of the right atrium; the frequency with which the SA node discharges electricity determines the rate at which the heart normally beats. The SA node keeps the heart beating in a regular manner. At rest, the frequency of the electrical discharges originating from the SA node is low, and the heart beats at the lower range of normal (60 to 80 beats/minute). During exercise or excitement, the frequency of discharges from the SA node increases, increasing the rate at which the heart beats. In people who exercise regularly, the resting heart rate may be below 50 to 60 and is not of concern.
The electrical discharges pass from the SA node through the special tissues of the atria into the AV node and through the AV node to the special conduction tissues of the ventricles, causing them to contract.
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