How Cocaine Affects the Cardiovascular System

Cocaine, one of the most commonly used illegal drugs, can cause toxic effects, including dangerous cardiovascular events. Cocaine increases heart rate, blood pressure, and the force of the heart's contractions, which can raise the risk of certain heart problems.

Cardiovascular conditions associated with cocaine use include:

• Heart attack
• Aortic dissection
• Coronary artery aneurysm
• Myocarditis and cardiomyopathy
• Cardiac arrythmias
  
• Stroke
  

Cocaine use can produce a variety of potentially catastrophic cardiovascular problems, which may be sudden and severe or may become long-term. Worse, these problems may occur even in people whose cocaine exposure is limited to occasional, recreational usage.

Cardiac Effects of Cocaine

Cocaine is a drug that inhibits the reuptake of norepinephrine in neurons throughout the body. Norepinephrine is a powerful neurotransmitter within the sympathetic nervous system, and when its reuptake is inhibited, the sympathetic nervous activity becomes greatly exaggerated and prolonged. 

The exaggerated sympathetic nervous activity has profound effects on the cardiovascular system. It substantially increases the force of the heart muscle as it contracts, and at the same time, it raises the heart rate and the blood pressure. These factors all greatly increase the work of the heart, and therefore the demand of the heart for oxygen and nutrients.

While it's causing the cardiovascular system to work so much harder, cocaine simultaneously limits the amount of work the heart can do without damaging itself. It does this by causing constriction of the capillaries, thus reducing the blood flow to the heart muscle.

In addition, cocaine promotes blood clotting within blood vessels, which limits blood flow to vital organs—including the heart.

Resulting Cardiovascular Conditions

Several important cardiovascular conditions can result from this combination of effects caused by cocaine use.

Myocardial Infarction

Myocardial infarction (heart attack) is a well-known complication of cocaine use, and can occur with any dose of cocaine, and even in first-time users. Most cocaine-induced heart attacks occur within a few hours of using the drug.

One study found that among a sample of more than 9,000 adults aged 18–45, cocaine users were almost seven times as likely to have a non-fatal heart attack. Another study found that among a sample of heart attack patients 39–48 years old, cocaine users were about twice as likely to die.

Aortic Dissection

Acute aortic dissection—a sudden tearing of the wall of the aorta—is an extremely painful and life-threatening condition. While there are many causes of aortic dissection, in young people cocaine use is a prevalent cause.

Coronary Artery Aneurysm

Coronary artery aneurysms are balloon-like dilations of coronary arteries. They are fairly common in cocaine users, with one study finding them in about 30% of cocaine users, vs. less than 8% among non-users. Coronary artery aneurysms are a cause of heart attack.

Myocarditis and Cardiomyopathy

Cocaine causes myocarditis, which is inflammation of the heart muscle. Myocarditis can lead to damage of the heart muscle (cardiomyopathy). As a result, heart failure may occur.

Cardiac Arrhythmias

Cocaine can induce a variety of difficult-to-treat cardiac arrhythmias, including the potentially fatal arrhythmias called ventricular tachycardia and ventricular fibrillation.

Stroke

Due to its effect on blood vessels, blood pressure, and blood clotting, stroke is up to seven times more likely in a cocaine user than a non-user.

Treatment Complications

In general, the treatment of cocaine-induced cardiovascular problems is similar to the treatment of those same cardiac problems when cocaine use is not a factor. However, cocaine use complicates therapy in a few important ways.

Beta-Blockers

Beta-blockers should not be used in patients currently under the influence of cocaine. Beta-blockers are very important for the treatment of coronary artery disease, heart attacks, angina, and heart failure.

However, in people who have taken cocaine, beta-blockers (which block beta-sympathetic effects of norepinephrine) “uncover” the alpha-sympathetic effects, leading to more constriction of the small arteries, and higher blood pressure. This takes a critical treatment tool out of the doctors’ hands when they are dealing with a heart attack.

Clot-Busting Drugs

When treating what appears to be an acute heart attack, the use of clot-busting drugs—drugs that produce fibrinolysis—should generally not be employed in a cocaine-user without first doing a cardiac catheterization.

This is because the electrocardiogram (ECG) changes that typically indicate that an acute heart attack is occurring may be seen in cocaine users who are actually not having a heart attack due to a blocked artery.

Stents

Doctors are reluctant to use stents to treat coronary artery disease in cocaine users because stent thrombosis (clotting off of the stent) is much higher in these people.

The bottom line is that, not only are the cardiovascular problems caused by cocaine especially dangerous, they are also especially difficult to treat, even by doctors who are very experienced in dealing with these problems.

A Word From Verywell

The use of cocaine can place enormous stress on the heart and the vascular system and can lead to several significant cardiovascular conditions. Furthermore, because of the multitude of negative effects on human physiology, treatment options are limited in people who have cocaine-induced cardiovascular disorders.