There are many types of heart disease, all of which have some effect on the heart. Different diseases will cause different effects but at the same time, one effect can be due to more than one disease. More than one disease can interfere with the heart and not let it fill with blood, cause it to fill up with too much blood or not be able to pump.
Heart Cannot Fill
The heart should normally pump approximately 5 liters of blood every minute, according to Elizabeth Corwin, Ph.D. in "Handbook of Pathophysiology." That amount of blood has to circulate throughout the body every minute so the red blood cells can deliver oxygen to all the tissues and organs in exchange for carbon dioxide. To pump that amount of blood, the heart must be able to fill up with blood. Some heart diseases do not allow the heart to fill to its normal volume. Hypertrophic cardiomyopathy is a heart disease where the ventricles, or the lower two chambers of the heart, and the wall between them are too thick. Because of the abnormal thickness, the heart cannot fill. Restrictive cardiomyopathy is a heart disease where the heart is restricted, meaning it cannot expand enough to be able to fill. This happens when diseases infiltrate the heart muscle.
Heart Fills Too Much
Blood leaves the right ventricle, passes through a valve called the pulmonary valve and goes to the lungs to get oxygen. Blood leaving the left ventricle has oxygen. It passes through an aortic valve, enters the aorta and then circulates throughout the body. Paul Tanser, M.D., professor of medicine at McMaster University writes about the heart diseases of these two valves in "The Merck Manual for Healthcare Professionals." Pulmonary regurgitation is the disease where the pulmonary valve is damaged. Blood comes back through the valve, back into the right ventricle. Pulmonary regurgitation causes too much blood to accumulate in the right ventricle and makes that ventricle get bigger as well. In aortic regurgitation, heart disease affects the aortic valve. Blood from the aorta passes backwards through the aortic valve into the left ventricle. Too much blood will fill the left ventricle, causing it to get larger.
Cannot Pump Blood Out
Dilated cardiomyopathy is the heart disease where the left ventricle is enlarged, or dilated. In "Current Medical Diagnosis & Treatment," Thomas Bashore, M.D., professor of medicine at Duke University Medical Center writes that physicians do not know yet what causes most cases of this heart disease. Many cases are due to chronic alcoholism and myocarditis, or the inflammation of the heart muscle. Because the heart is dilated, it cannot pump like it should. In congestive heart failure, the diseased heart is failing and cannot pump out enough blood like it should. In aortic stenosis, the valve is stenotic, or too narrow. The left ventricle is fine and can pump, but the blood cannot pass through the aortic valve like it should be able to.
References
- "Current Medical Diagnosis & Treatment 2010"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2010
- "Handbook of Pathophysiology"; Elizabeth Corwin, MSN, Ph.D., FNP; 2000
- The Merck Manual for Healthcare Professionals: Aortic Regurgitation
- The Merck Manual for Healthcare Professionals: Pulmonic Regurgitation
