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.
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.
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.
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
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 SA node (sino-atrial
node), the AV node (atrio-ventricular
node) and special tissues in the ventricles that conduct electricity.
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 (60-80 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 50-60 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 and causing the
ventricles to contract.