Experts at the Centers for Disease Control and Prevention (CDC) estimate that 5.7 million Americans live with heart failure. And Gregg C. Fonarow, MD, director of the Ahmanson-University of California Los Angeles Cardiomyopathy Center, warns, "There will be close to one million new cases this year."
Diseases that damage the heart, such as heart disease, diabetes and high blood pressure, are the leading causes of heart failure, says the National Heart, Lung, and Blood Institute. Distinct from sudden cardiac arrest, heart failure does not necessarily mean that the heart suddenly stops beating altogether.
But the CDC warns that it's a very serious and often progressive condition. It means that the heart muscle is in a severely weakened state and can no longer reliably pump an adequate amount of blood and oxygen to satisfy the needs of all the other organs in the body.
Roughly half of all people with heart failure will succumb to the disease within just five years of being diagnosed, the CDC notes. And, with one of every nine American deaths due to heart failure, at least in part, it's a very common disease. Still, people often don't know that heart failure can manifest in several different stages.
Heart Failure's Progression
According to the American Heart Association (AHA), congestive heart failure (CHF) — often simply called heart failure — is when your heart has weakened and can't keep up with the flow of blood coming into it through the veins. The result is a blood traffic jam, with blood backing up and causing body tissues to congest and swell. In some cases, fluid can build up in the lungs, causing shortness of breath and respiratory distress.
As heart failure progresses, the problem becomes centered on the left side. It's known as left-sided heart failure (more on this below). Ultimately, the end result is right-sided heart failure. This is when the right side of the heart, which is smaller than the left, loses the power to adequately pump "used" blood — blood that's been depleted of oxygen and is in need of a lung-provided oxygen refill. If this process slows to a crawl, the result is also a back-up of blood in the veins.
Understanding Left-Sided Heart Failure
Under normal circumstances, after the lungs load incoming blood cells with oxygen, those cells circulate into the left side of the heart. In turn, this vital section of the heart pumps the blood through the left atrium and left ventricle, injecting oxygen-rich blood throughout the body. According to the AHA, most of the heart's pumping power is located in these left chambers, and that's where heart failure typically worsens first.
"The most common form of heart failure is left-sided heart failure," explains Dr. Fonarow. When right-sided heart failure does occur, it's usually a result of left-sided failure. On its own, "isolated right heart failure is less common," he notes.
When the left side gets too weak, one of two things can happen. One possibility is that the left ventricle loses the ability to contract normally, resulting in systolic failure. In this situation, the left-side of the heart is no longer able to push blood out of its chamber to spread throughout the body.
Another is diastolic failure. In this situation, the left ventricle becomes stiff, losing the ability to sufficiently relax. The result is that the left side of the heart can no longer fill up with blood between heartbeats.
Know the Early Signs of Left-Sided Heart Failure
If you're concerned about worsening heart failure, be on the lookout for a number of telltale early signs of left-sided heart failure. They include shortness of breath, fatigue, swollen legs and a rapid heartbeat, Dr. Fonarow notes.
Some people also experience chest pain or a dry or phlegmy cough, sometime referred to as CHF dry cough. It's possible to experience symptoms that affect other aspects of well-being from dizziness to fatigue, an inability to exercise and the loss of appetite.
Read more: The 14 Best Foods for Your Heart
Respiratory distress is another key indicator, Dr. Fonarow warns. It can take the form of fast breathing or shortness of breath at night, when lying down or when exercising.
Water retention, bloating, excess urination at night, palpitations, swollen feet, swollen legs or weight gain should also be viewed as potential signs of the development of left-sided heart failure, he adds.