Heart Failure: what causes it?

Heart failure is when the heart is too weak to pump blood through the body. It poops out. The patient becomes winded on exertion as the person's heart cannot keep up with demands on the body. So, what causes heart failure? Here's what to know.

1. Hypertension: Coronary artery disease is one ailment that causes blood vessels to become narrow. Years of working hard to pump blood through narrowed vessels can cause the heart to become hypertrophied (enlarged). A large bicep is good, and it's a sign of good health. A large heart is a sign of a weak pump. It is bad. Eventually, it will tire and become an ineffective pump. In fact, 60% of heart failure cases are the result of high systemic blood pressure and coronary artery disease.

2. Coronary Artery Disease (CAD): According to the National Heart, Lung and Blood Institute (NHLBI), CAD is a disease whereby plaque builds up inside the coronary arteries (arteries that supply oxygenated blood to the heart). This plaque buildup is called atherosclerosis, and will slowly cause these arteries to narrow, and thus force the heart to work harder to oxygenate itself. This can often lead to portions of plaque to break free, forming a clot in the heart, and causing a Myocardial Infarction, otherwise known as a heart attack (I'm sure you knew that, but just saying). 
3. Myocardial Infarction: This is where plaque from diseased coronary arteries breaks free and blocks blood flow to a part of the heart, causing heart (muscle) tissue in that area to die. This can cause heart failure. In fact, it can cause severe heart failure symptoms, including dyspnea, orthopnea, hypoxia, cyanosis, and even death.

4. Pulmonary Hypertension: This is where the pulmonary vascular resistance increases to a point where it causes the right heart to become hypertrophied. This makes the right heart a weaker pump. This often leads to left heart failure. Causes of this are COPD, cystic fibrosis, and pulmonary fibrosis. I go into more detail in my post, "Links Between COPD and Heart Failure."

5. Cor Pulmonale: This right heart hypertrophy. It means the right heart has become a weak, ineffective pump. This is responsible for 10-30% of admissions for CHF. For more detail, again check out, "Links Between COPD and Heart Failure."

6. Heart Disease: About 30-40% of heart failure is caused by heart disease.

7. Heart Valve Disease: This constitutes about 20% of heart failure. When the valves of the heart fail to work properly, this causes the heart to become a weaker pump.

8. Congenital Heart Defects: These are diseases a person is born with, and you can read about this in my post, "Congenital Heart Anomalies."

9. Drug abuse: Amphetamines, heroin, cocaine and other drugs may actually numb the heart so much that it becomes a less effective pump and ultimately fails.

10. Alcohol Abuse: Years of abusing your body can cause it.

11. Infection: Influenza, mumps, and rabies are infections that can stun the heart, as are various bacterial infections (streptococcal, rheumatic heart disease). Likewise, sepsis (a systemic blood infection) can also weaken the heart's ability to pump blood.

12. Other diseases: Leukemia, neurologic disorders (Duchenne's muscular dystrophy, Multi-system organ failure, Sepsis, Trauma, cardiac tamponade (squeezes the heart), diabetes and obesity. Diseases such as hemochromatosis or amyloidosis that cause the heart to stiffen, thus decreasing the heart's ability to relax.

All of the above can cause the heart to become a weaker pump, thus resulting in a loss of cardiac output, and causing pulmonary edema and other symptoms that mimic asthma.