Abnormal blood vessels
Similar to valves to open incompletely, blood vessels that are too narrow at a certain point cause the heart to work harder. In addition, blood vessels can be connected incorrectly, sending deoxygenated blood to the body or already oxygenated blood back to the lungs.
Congenital valve defects
A valve in the heart may be unable to open completely, or unable to close completely, due to a defect of function or shape. These defects force the heart to work harder as it moves blood through the heart.
This defect is caused by a malformed heart valve that does not properly close to keep the blood flowing in the proper direction toward the lungs.
This is a genetic disorder that affects the body's connective tissue, the tissue that holds all the body's cells, organs and tissue together. Patients with Marfan Syndrome are at risk of tearing or bursting of their major blood vessels.
Septal defects ("holes in the heart")
A septal defect can occur between the two ventricles (pumping chambers) of the heart, which is called a ventricular septal defect, or between the two atria (filling chambers), which is called an atrial septal defect. With either type, oxygenated blood coming from the lungs gets mixed with deoxygenated blood returning from the body. Such holes can lead to complications and in most cases require repair for preventative purposes.
Tetralogy of Fallot
This heart defect features four distinct problems: a hole between the lower chambers of the heart, an obstruction between the heart and lungs, the aorta (blood vessel) covers the hole in the lower chambers and the muscle surrounding the lower right chamber becomes overly thickened.