Doctor's Notes on Ventricular Septal Defect
The two lower chambers of the heart are the ventricles, and the wall between them is called the septum. A hole in the septum is called a septal defect, also referred to as a “hole in the heart.” This abnormality usually develops before birth and is found most often in infants. It causes oxygenated blood to mix with unoxygenated blood and results in the ventricles working harder than they should, which can lead to pulmonary hypertension or congestive heart failure.
Small holes in the ventricular septum usually produce no symptoms but a child's doctor may notice a heart murmur. Large holes in the ventricular septum can cause symptoms including rapid breathing, sweating, pale skin, fast heartbeats, decreased feeding, and poor weight gain. When a ventricular septal defect is not detected early on, it can cause more severe symptoms later in life including high pressure in the lungs (pulmonary hypertension), which causes fainting, shortness of breath, chest pain, result in a stroke, and can cause bluish discoloration of the skin (cyanosis).
Heart Disease : Test Your Medical IQ Quiz

In the U.S., 1 in every 4 deaths is caused by heart disease.
See AnswerREFERENCE:
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.