Third-degree heart block usually involves treatment with a temporary or permanent pacemaker. In some situations, treatment may include medications or synthetic hormones.

Third-degree heart block, also known as complete heart block, is a potentially life threatening condition involving the electrical system that keeps your heart beating consistently and vigorously.

Third-degree heart block is the most serious of the three types of heart block and is a medical emergency.

With third-degree heart block, the electrical impulses that travel from your heart’s upper chambers (atria) to the lower chambers (ventricles) are blocked or interrupted. This can cause the heart to slow down or stop entirely. Immediate medical treatment is crucial to restore healthy heart function.

Treatment usually involves a pacemaker to maintain a healthy rate and rhythm. In some cases, treatment may include medications. This article will take a closer look at the different treatment options for third-degree heart block.

The goal of third-degree heart block treatment is to restore a healthy heart rate and rhythm to ensure that enough blood is pumped out of the heart with each heartbeat. Because third-degree heart block is often a complication that’s caused by another condition, treating the underlying condition is also important.

The main treatments for third-degree heart block include the strategies outlined below.

The implantation of a temporary or permanent pacemaker is standard treatment for most people with a diagnosis of third-degree heart block.

A pacemaker is a small, battery-powered device that’s surgically implanted in the chest, near the collarbone. The device contains two leads (wires) that extend into the heart and transmit electrical signals to maintain a steady heartbeat.

The severity and cause of third-degree heart block will determine whether a temporary or permanent pacemaker is needed. The National Organization for Rare Disorders notes that the age of symptom onset and the presence of congenital heart defects are the main criteria doctors use to recommend a permanent or temporary pacemaker.

The Heart Rhythm Society guidelines recommend a permanent pacemaker in pediatric patients if there’s no other reversible cause of the heart block. A separate 2018 set of treatment guidelines, published by the American Heart Association, also advises the use of a permanent pacemaker if the cause isn’t reversible, regardless of symptoms.

Doctors sometimes administer atropine, an anticholinergic drug, intravenously to people who experience heart block.

Atropine acts on the heart’s atrioventricular (AV) node — a small region of the heart that carries electrical impulses from the atria (upper chambers of the heart) down to the ventricles (lower chambers).

This drug isn’t always as effective at treating third-degree heart block as it is for treating first- or second- degree heart block. But in some cases, it can help revive normal electrical patterns.

The bacterial infection that causes Lyme disease can also trigger third-degree heart block, though this is an uncommon complication.

A 2021 report notes that injections of the antibiotic ceftriaxone helped fight the infection and began to restore healthy heart function.

It was followed by the use of the oral antibiotic doxycycline, which led to a full reversal of third-degree heart block and negated the need for a pacemaker.

While a pacemaker is an implanted device that operates within the chest wall, transcutaneous pacing is done from outside the body.

Special pads are placed on the chest and back to deliver electrical signals to the heart to restore healthy electrical activity. It’s usually a temporary measure that’s used until a permanent solution, such as pacemaker, can be implemented.

However, in some cases, when a heart attack triggers third-degree heart block, transcutaneous pacing may be enough to restore a healthy heart rate and rhythm while other procedures help get blood flowing properly throughout the heart muscle.

In the event of a heart attack, your healthcare team may use synthetic versions of catecholamine hormones as a temporary measure while you wait for a pacemaker.

Catecholamines is an umbrella term that’s used for the adrenal hormones dopamine, norepinephrine, and epinephrine (adrenaline), which naturally occur in your body.

The use of catecholamines may also be appropriate if third-degree heart block occurs after a heart attack that’s treated quickly, allowing blood flow to return to normal.

One type of catecholamine hormone that’s used to treat third-degree heart block is epinephrine. Also known as adrenaline, naturally occurring epinephrine is one of the hormones responsible for the body’s fight-or-flight response to threats.

Research published in 2021 suggests that after certain types of heart attacks, epinephrine and another catecholamine hormone called dopamine can temporarily keep sufficient electrical activity going in the heart. It’s usually given while a person waits for a pacemaker to be implanted.

Epinephrine is sometimes given when atropine isn’t able to bring back the heart’s normal flow of electrical energy.

Third-degree heart block can be fatal if not treated promptly and effectively. Two important factors that can affect prognosis are the presence of heart disease and structural problems with the heart.

People with third-degree heart block face greater risks of heart failure and mortality. In a 2021 study of more than 3,000 heart attack cases caused by a complete blockage of one or more coronary arteries, the rate of in-hospital mortality was 17.9% for people with third-degree heart block compared with 3.6% for people without complete heart block.

However, with a pacemaker and a heart-healthy lifestyle, the prognosis for a long life and the ability to enjoy everyday activities is usually encouraging.

Keys to good heart health include:

  • careful control and monitoring of blood pressure, cholesterol, and blood glucose
  • following a heart-healthy diet, such as the Mediterranean-style eating plan
  • consuming little or no alcohol
  • getting regular aerobic exercise
  • managing stress effectively
  • getting regular checkups with your doctor or cardiologist (heart specialist)

Treating third-degree heart block usually means living with a pacemaker. Because a pacemaker may last only 10 years, you may need to have it replaced, depending on your age.

In some cases, third-degree heart block may also be treated with medication, such as atropine, antibiotics, or catecholamine hormones.

If you’ve had third-degree heart block, it’s important to work closely with your cardiologist and to make lifestyle changes to help boost the health of your heart.