What are heart failure, heart attack and cardiac arrest?
12/28/2016, 6 a.m.
(CNN) Singer George Michael died Christmas Day at age 53 when his heart "failed" him while lying peacefully in bed, his manager Michael Lippman said, according to the UK-based Press Association.
Typically, heart failure refers to the heart not working optimally but it can be treated. It does not mean the heart has stopped functioning completely, though in some cases it leads to that.
If Michael's heart not only failed but also stopped beating completely, he would have had "just minutes -- just minutes," said Dr. Nieca Goldberg, a spokeswoman for the American Heart Association who had no direct knowledge of Michael's condition or death.
"That's why it's very important for all of us to learn how to do cardiopulmonary resuscitation (CPR)," added Goldberg, who is also medical director of the Joan H. Tisch Center for Women's Health at the NYU Langone Medical Center in NYC. "That's the first step when someone collapses to help save their life."
What is heart failure?
The American Heart Association describes heart failure as a condition that occurs when this important organ, essentially a pump, cannot effectively push blood out through the arteries and circulatory system to the body's other organs and tissues.
Congestive heart failure, a worsening of this general condition, means blood flow from the heart through the arteries has slowed while blood returning to the heart through the veins has begun to back up and combined they cause congestion -- a blood traffic jam -- in the body's tissues.
The result is edema, or swelling, usually in the legs and ankles, though edema can happen anywhere in the body. Heart failure also impairs the kidneys' ability to dispose of water and sodium, causing even more swelling. When pulmonary edema happens, fluid collects in the lungs and interferes with breathing.
Conditions that can lead to heart failure include high blood pressure, diabetes, obesity and coronary artery disease -- when plaque builds up in the walls of arteries causing them to narrow and increasing the difficulty of pumping blood.
Heart failure, then, is a medical condition that needs to be treated to prevent a life-threatening heart attack.
What is a heart attack?
"A heart attack is a circulation problem," said Goldberg. When circulation is blocked or cut off in some way and blood is no longer supplied to the heart muscle, this can damage that muscle, she explained. Though commonly described as a heart attack, doctors refer to this condition as "myocardial infarction."
Blocks causing heart attacks are mostly caused by a buildup of plaque in the arteries. Plaque forms when cholesterol combines with fat, calcium and other substances in the blood.
Combined, these separate elements harden into plaque, which can then rupture causing a blood clot to form. Large enough clots can completely block the flow of blood through an artery leading to a life-threatening result of a heart attack.
"People who are at risk for heart attacks are people who have a family history of heart attack, having high cholesterol, high blood pressure, diabetes, lack of exercise, cigarette smoking -- the major risk factors we always discuss," Goldberg said.