Category: Surgery

The Patient’s Guide to Simple Congenital Heart Defects

What is Congenital Heart Defect (CHD)

This is an abnormality in the function or structure of the heart. This includes things that affect the walls of the blood vessels, organ, that carries the blood to and from it, and the valves which regulate blood flow. Some CHDs are minor and cause no noticeable symptoms. Others so severe that they can place the patient’s life at risk.

Symptoms vary according to the type of defect suffered, as well as its severity. In this article, we’ll explore a few of the most common simple CHDs, including septal defects and valve problems.

Atrial Septal Defect

Artial Septal Defect

Visual Representation of ASD

Inside the heart, the left ventricle and atrium are separated from the ventricle and right atrium by a wall. This wall is known as the septum. It blocks the deoxygenated blood which on the right side from mixing with the newly-oxygenated blood on the left side. Many kids are born with a hole in this wall. If the hole is in between the atria and is known as atrial septal defect (ASD).

When an ASD is small, symptoms may be barely noticeable. Even though blood between the right and left sides is allowed to mix, the amount that does so is negligible, and thus does not pose a significant problem. When the defect is bigger, symptoms are more pronounced. A larger volume of oxygenated blood in the left atrium flows back in the right atrium rather than being pumped out of the heart to the rest of the body. Treatment is often necessary.

Ventricular Septal Defect

A ventricular septal defect (VSD) is the same to an ASD. The only difference is that the hole is in between the two ventricles. The effect is normally the same. Oxygen-rich blood that would otherwise be pumped into the aorta can flow back to right ventricle.

A small VSD is unlikely to have severe consequences. A larger hole, however, can cause fatigue, difficulty taking deep breaths, and in extreme cases, cyanosis due to a marked lack of oxygen in the blood cells. Occasionally, a large ventricular septal defect can cause pulmonary hypertension, a condition where high blood pressure causes the heart to work harder. Unless the septal hole is corrected, the patient may eventually experience heart failure.

Valve Abnormalities

The heart is equipped with valves that manage blood flow between the chambers and the arteries attached to them. The right ventricle and atrium are separated by the tricuspid valve; the left atrium and ventricle are separated by the mitral valve; blood flows from the right ventricle to the pulmonary arteries through the pulmonary valve, and blood moves from the left ventricle to the aorta through the aortic valve.

These valves can be diseased in a few ways. First, they might fail to close completely, allowing blood to flow backward. Second, they may be stiff, and thus fail to open properly. When this happens, the chambers are unable to empty. Third, a valve might be unable to open at all.

Signs of a valve defect vary based on which valve is affected. For example, a regurgitant – or, “leaking” – mitral valve will prevent oxygen-rich blood from being circulated to the body. This leads to fatigue and related issues. A stenotic – or, stiff – pulmonary valve can increase blood pressure in the right ventricle, leading to possible heart failure.

There are a lot of congenital diseases known to man, but some of them can be corrected. Congenital tooth problem can be corrected easily.

Chromosomal Abnormalities and PGD

Pre-implantation genetic diagnosis (PGD) is a method aimed at eliminating embryos created by in vitro fertilization (IVF) that have abnormal chromosomes or carry a serious genetic disease before pregnancy begins. Genetic diagnosis of preimplantation (PGD) refers specifically to when one or even both of the genetic parents have a known genetic abnormality, and testing is conducted at an early level to determine if it does not carry a genetic anomaly. These structural or numerical defects in embryos are more common in elderly pregnant women, especially those older than 35 years. This situation can lead to infertility, as it reduces the likelihood of implantation, and also causes unwanted miscarriages. In fact, 40 out of 100 pregnancies in women aged 39 and older will lead to problems associated with structural or numerical chromosomal defects. In contrast, genetic preimplantation screening (PGS) refers to methods in which embryos from suspected chromosomal-genetic parents are screened for aneuploidy.

Since only implanted embryos are transferred to the uterus for implantation, genetic testing of preimplantation is an alternative to diagnostic procedures for new diagnosis, which is often accompanied by a complex decision to terminate the pregnancy if the results are unfavorable. PGD ​​and PGS are currently the only possible options to avoid the high risk of contracting a child with a genetic disease before implantation. This is an attractive remedy to prevent hereditary genetic disease, thereby eliminating the dilemma of ending pregnancy after an unfavorable prenatal diagnosis.

Indications for Preimplantation Genetic Screening

Most of the early loss of the pregnancy can be attributed to aneuploidy. Since only chromosomally normal embryos are transferred to the uterus, the risk of losing the first and second trimester is markedly reduced. There is currently no specific list of indications for genetic screening for preimplantation (PGS).

Thousands of clinical cycles of genetic diagnosis of preimplantation were performed around the world, resulting in the birth of hundreds of healthy children.

The advantages or benefits of PGD are listed below:

  • The procedure is performed before implantation, thus reducing the need for amniocentesis later during pregnancy.
  • The procedure is performed before implantation, which allows couples to decide if they want to continue the pregnancy.
  • This procedure allows couples to pursue biological children who might not have done it otherwise.
  • This procedure can help reduce costs, usually associated with congenital disabilities.

Also, hundreds of babies were born after PGD / PGS around the world. To date, there are no reports of an increase in the frequency of fetal development or other identifiable problems.

The main reason for choosing this PGD procedure is that the risk of miscarriage during normal pregnancy decreases from 23 to 9 percent, the probability that an embryo attached to the uterus almost doubles, the chances of a clinical pregnancy and returning home with an increase in the baby and the frequency of the multiple pregnancy decreases.

How is the PGD Procedure Performed?

Preimplantation genetic diagnosis (PGD) is a screening test used to determine the presence of genetic or chromosomal disorders in embryos obtained by in vitro fertilization (IVF). The following are steps related to the implementation of the PGD procedure.

1. The patient’s suitability for PGD is evaluated by a doctor who specializes in the related disease.
2. The couple is then prepared for the IVF procedure.
3. The egg taken from the mother is impregnated with the father’s sperm in the laboratory environment.
4. Embryologists extract one or two blastomere cells from the removed embryos by biopsy.
5. Cells extracted with biopsy are subjected to a special staining technique (FISH), which allows you to examine the chromosomes under a microscope after the fixation process.
6. Embryos with structural or quantitative chromosomal defects are selected and removed. Then, healthy embryos are transferred to the mother’s uterus.

Although PGS was included in the treatment of patients undergoing IVF treatment, its indications, usefulness, and results remain an active area of ​​research in the field of reproductive medicine. As preimplantation is optimized for medical disorders at the early level, its place in medicine and society will continue to cause controversy and ethical debate.

Despite all its advantages, the cases in which this method will be used should be carefully selected. It should be remembered that the PGD procedure requires that the cell is removed from the embryo by biopsy. Thus, there is a chance to harm the embryo, and this procedure has a 10 percent error. Thus, it is believed that it causes more harm than good when it is performed unnecessarily.