Whitney Houston's death: What is atherosclerotic heart disease?

Singer Whitney Houston passed away at age 48. (AP Photo/Christof Stache)

When Whitney Houston’s autopsy report was released Thursday, the L.A. coroner’s office that examined her body listed drowning and “effects of atherosclerotic heart disease and cocaine use,” as the official causes of death.

What exactly is atherosclerotic heart disease, and how does cocaine contribute to it?  Heart and addiction specialists weigh in below.

Atherosclerotic heart disease is a condition in which plaque hardens in the arteries and narrows them, according to the National Heart Lung and Blood Institute.  This limits the flow of oxygen-rich blood to the organs and other parts of the body and can lead to serious problems including heart attack, stroke and death.

“The build of plaque in the heart tends to occur slowly over the years, so that most people who do have it tend to be older,” Dr. Phil Ragno, director of cardiovascular health and wellness at Winthrop Hospital, told FoxNews.com.  “It builds up like layers of an onion, so what happens is when enough of the artery is narrowed down it can cause symptoms or even a heart attack.”

While heart disease can be brought on by a number of factors—including poor diet, infrequent exercise or alcohol abuse—cocaine can exacerbate the condition.  Repeatedly exposing the blood vessels to the chemical make-up of the drug can cause multiple areas of scarring within the arteries and heart, according to Ragno.

When a person engages in cocaine use on top of suffering from advanced atherosclerotic heart disease, the impact on the heart can be devastating.  Cocaine use increases heart rate, blood pressure and causes the blood vessels to constrict, reducing the supply of blood to the heart.

“[Cocaine use] puts extra demand on the heart while at the same time restricting blood supply to the heart,” Ragno said.  “So at the time when the heart needs the most amount of blood, it’s getting the least amount of blood.”

In some cases, the addict may experience a heart attack or fatal heart arrhythmia.

“Cocaine works in two ways—as a stimulant and anesthetic,” Ragno said.  “As an anesthetic, it blocks some of the channels in the heart that move electrolytes such as sodium and potassium.  This raises the risk of suffering from an irregular heartbeat or arrhythmia.”

According to Dr. Nicholas Kardaras, an addiction specialist and clinical professor at the Health Sciences Center of Stony Brook University in Stony Brook, N.Y., while it’s impossible to say how many addicts suffer from heart problems, “it’s fair to say a significant percentage of people have a long-term history of cocaine use do.”

“If you use cocaine chronically, it will have a deleterious effect on the heart without a doubt,” Kardaras added.  “How serious the condition is depends on other risk factors, such as diet and exercise [frequency], and how much cocaine you’ve been taking and for how long, among other factors.”

The autopsy report

One of the main risk factors for death during drug usage is that the plaques that build up in the arteries can rupture.  Cocaine usage specifically can cause enough stress to lead to a rupture and result in a heart attack.

However, because Houston’s death was attributed to drowning rather than a heart attack, Ragno and Kardaras both said it was unlikely she experienced one.

“She probably suffered a heart rhythm that left her disabled and debilitated, which caused her to become submerged and drown,” Ragno said.

Kardaras added that while the coroner said the other drugs in her system—Xanax, Flexeril and Benadryl—did not contribute to Houston’s death, he had trouble seeing how they could be completely discounted.

“Those substances are sedatives,” Kardaras said.  “They all have a drowsy effect.  I would say it’s more likely to slip under the water and lose consciousness from those other medications…Basically, the conclusion was, she had a heart episode based on her heart condition that led her to slip underwater, and I’m saying we can’t be sure of that.

“Heart attacks due to build up in the arteries are a long chronic condition, and you don’t lose consciousness unless you have a heart attack—but that’s not what the coroner’s saying happened.”

The doctors stressed that it’s possible for addicts to improve their long-term health and survival if they sober up—even after a heart condition develops.

“You’ll still have heart disease, but you can stop its progress if you stop abusing drugs and start eating healthy and engaging in other healthy lifestyle choices,” Kardaras said.

Ragno added: “The build up from scar tissue tends not to get better.  But with a healthy lifestyle plaque build-up may decrease and improve over time, so you decrease your future risk of heart problems and increase your risk of a healthier future.”

However, he warned that people who have abused cocaine should notify their physician before embarking on a new exercise or fitness regimen, because it may put too much strain on their hearts.