A virtual look at what causes heart failure

Heart failure does not have a single cause, but high blood pressure and other health conditions are contributing factors. Join Dr. Jen Caudle on a virtual look at the heart and how it pumps.

Transcript

00:00

Heart failure is a serious condition, affecting over six million people in the United States alone. [MUSIC PLAYING]

00:09

Heart failure occurs when the heart is weakened and loses its ability to deliver a sufficient amount of blood and oxygen to meet the needs of the body.

00:18

There's not a single cause for heart failure, but conditions such as high blood pressure and various diseases contribute to the gradual progression

00:25

of a weakened heart. Most often, heart failure involves the left side of the heart, where a large chamber called the left ventricle ejects oxygen-carrying blood

00:34

for circulation throughout the body. In order to better understand what happens during heart failure, we must go inside and actually

00:41

look at how this marvelous pump sends oxygen-rich blood out to the body. The ventricle walls, which are made of muscle

00:48

receive blood from the chamber above and then rapidly contracts to force blood out of the heart. This all happens very quickly.

00:56

So now watch in slow motion. Notice that not all of the blood leaves the chamber. Some stays behind and waits for the next cycle.

01:04

In fact, in a healthy heart, a little over half is ejected with each contraction. So it makes sense to call this amount the ejection fraction.

01:13

A normal ejection fraction is between 50% to 70%. When a person has heart failure, the muscles of the ventricle chamber experience

01:21

damage due to stress from any number of causes, including high blood pressure, diabetes, and cardiovascular disease.

01:28

The heart response to these challenges in different ways, but ultimately, the muscle is weakened, and the heart's ability to pump blood is reduced.

01:36

In some cases the chamber walls become stretched and thin. In this weakened state, the walls cannot contract with

01:43

enough force to eject a normal amount of blood. In this type of heart failure, the percentage of blood ejected

01:49

is less than 40%. Normal was over 50%. This condition is called heart failure

01:56

with reduced ejection fraction. You'll see it in writing as HFREF. In another type of heart failure the heart muscle

02:04

becomes thickened and stiff. When the walls are stiff, the chamber can't feel completely, so it holds less blood.

02:11

In this case, the amount of blood ejected is less than normal because it starts with less to begin with,

02:17

but the percentage is the same as normal, over half. And that's why this condition is called heart failure

02:23

with preserved ejection fraction, or HFPEF. It's estimated that preserved ejection fraction accounts for as much as 54% of heart failure patients.

02:32

At this time, there is no cure for heart failure. However, many people with this condition are able to live normal lives through a combination

02:40

of medical treatments and changes to lifestyle. Talk with your doctor to learn more. [WHOOSH]