Dr. Mersch received his Bachelor of Arts degree from the University of California, San Diego, and prior to entering the University Of Southern California School Of Medicine, was a graduate student (attaining PhD candidate status) in Experimental Pathology at USC. He attended internship and residency at Children's Hospital Los Angeles.
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.
A ventricular septal defect (VSD) is a heart malformation present at birth. Any condition that is present at birth can also be termed a "congenital" condition. A VSD, therefore, is a type of congenital heart disease (CHD). The heart with a VSD has a hole in the wall (the septum) between its two lower chambers (the ventricles).
How common is a VSD?
The most frequent types of congenital malformations affect the heart. It is estimated that approximately
eight in 1,000 newborns have CHD. A VSD is the most frequent of the various types of CHD (25%-30% of all CHD). Approximately one infant in 500 will be born with a VSD.
What is the normal design of the heart?
The heart is made up of four separate chambers. The upper right chamber (atrium) receives blood back from the body with much of the oxygen extracted by the body organs and tissues. The blood is then pumped through a one-way valve into the lower right chamber (ventricle) from which it is pumped to the lungs to be again enriched with oxygen. This highly oxygenated blood then returns to the upper left sided chamber (atrium) and next passes through a one way valve into the lower left chamber (ventricle). From there, the oxygenated blood is pumped out into a large blood vessel (the aorta) and is distributed throughout the body through arteries.
The two upper chambers (right and left atria) are separated by a wall of muscle called the septum. Similarly the two lower chambers (right and left ventricles) are also separated by a separate muscular septum. These septa (plural of septum) keep the lower oxygenated blood that has returned from the body from mixing with the highly oxygenated blood which has returned from the lungs.
A VSD is a hole in the ventricular septum.
How do VSDs cause problems?
The pressure generated during contraction by the left ventricle is higher than that generated by the simultaneous contraction of the right ventricle. Blood will thus be pushed through the VSD (also called "shunted") from the left ventricle to the right ventricle. The right ventricle has to do extra work to handle the additional blood volume. It may have trouble keeping up with the load and enlarge, affecting its ability to pump efficiently. In addition, the lungs receive too much blood under too much pressure. The arterioles (small arteries) in the lungs thicken in response to the excess blood under excess pressure. If this extra pressure persists, permanent damage can be done to the lungs.
It makes a considerable difference whether the size of the VSD is small or large.
A heart murmur is the sound generated when blood flow within the heart is not smooth. Causes of heart murmurs can be functional, congenital, or caused heart valve conditions. Symptoms of a heart murmur may be none, or may include chest pain, shortness of breath, and arm, leg, and ankle swelling. Treatment of a heart murmur depends on the cause.
Birth defects have many causes and currently, are the leading cause of death for infants in the first year of life. Some of the causes of birth defects include genetic or chromosome problems. Exposure of the mother to rubella or German measles during pregnancy, or using drugs or alcohol during pregnancy. The treatment for birth defects depends upon the condition of the effected child.
An angiogram is an X-ray image of blood
vessels after they are filled with a contrast material. An angiogram of the
heart, a coronary angiogram, is the "gold standard" for the evaluation of
coronary artery disease (CAD). A coronary angiogram can be used to identify the exact location and severity of CAD.
How is a coronary angiogram performed?
Coronary angiography is performed with the use of local
anesthesia and intravenous sedation, and is generally not significantly uncomfortable.
In performing a coronary angiogram, a doctor inserts a small
catheter (a thin hollow tube with a diameter of 2-3 mm) through the skin into an
artery in either the
groin or the arm.
Guided with the assistance of a
fluoroscope (a special x-ray viewing instrument), the catheter is then advanced to the opening of the
coronary arteries (the blood vessels supplying blood to the heart).