When an artery becomes blocked in a heart attack, the process of restoring healthy blood flow to the heart is called reperfusion. It usually involves a combination of medications to break down a blood clot (thrombolysis) and procedures such as angioplasty to open up a narrowed blood vessel. But reperfusion therapy isn’t without some risk.

A reperfusion arrhythmia (RA) is one of several types of injuries to the heart muscle caused when blood flow to the heart resumes after it has been blocked or slowed.

An arrhythmia is a heart rhythm disturbance and a risk factor for stroke and other cardiovascular complications.

If an RA is identified, the use of anti-arrhythmic medications or other treatments may be necessary to avoid life threatening complications.

An RA is one of the more common types of injuries related to cardiac reperfusion. Others include:

  • changes to the smallest blood vessels
  • death of myocytes (heart muscle cells)
  • rupture of a layer of your heart wall

An RA is an abnormal heart rhythm that affects how efficiently your heart functions. The rhythm disturbance that results from reperfusion is often located in your heart’s lower chambers (ventricles), which pump blood to your lungs and the rest of your body.

Arrhythmias are problems related to your heart’s electrical system, which normally maintains the steady, synchronized beating of the ventricles and atria (heart’s upper chambers). Once that rhythm is disturbed, complications such as stroke, heart failure, or sudden cardiac arrest can occur.

An arrhythmia can originate at just about any point throughout your heart’s electrical network. It can cause your heart to beat slower or faster than normal or in a chaotic, unpredictable pattern.

Some of the most common reperfusion arrhythmias include:

  • Accelerated idioventricular rhythm: This type of arrhythmia is an abnormal rhythm involving the ventricles. It often occurs when blood flow is restored after a heart attack.
  • Atrial fibrillation (AF or AFib): During AFib, there’s an irregular and accelerated beating of the atria. It’s the most common RA, representing up to 28% of arrhythmias following reperfusion, according to a 2021 study of RA management.
  • Atrioventricular block, sometimes called “heart block”: This arrhythmia occurs when the electrical signals controlling your heartbeat become entirely or partially blocked.
  • Sinus bradycardia: Sinus bradycardia is a slow heart rhythm originating in the sinus node, the collection of cells known as the heart’s “natural pacemaker.”
  • Ventricular tachycardia: Ventricular tachycardia is an abnormally rapid heart rate originating in the ventricles.

Depending on the nature of your RA, the symptoms can vary. In very mild cases, you may not have any noticeable symptoms.

When obvious symptoms are present, they can include any of the following:

Several different factors can trigger an RA. A 2018 article suggests that the most common cause of RA is delayed after depolarization (DAD).

DADs are electrical charge changes within heart muscle cells. This usually occurs when too much calcium enters the cells, disrupting the balance of electrolytes necessary for a healthy heart rhythm. Calcium overload occurs due to the loss of magnesium in the myocytes when blood flow through the artery is blocked, according to a review of studies.

As part of reperfusion therapy, an individual is monitored for changes in blood pressure, heart rate, and other markers of healthy heart function. Your heart rhythm is recorded before, during, and after reperfusion using an electrocardiogram (EKG).

An EKG can identify changes in your heart rhythm in real time, so if your heart goes into an arrhythmia while you’re being monitored, your healthcare professionals will be able to identify it.

However, an RA may develop hours or days after your procedure. It’s important to know the signs and symptoms of RA or other reperfusion injuries that may occur and know how to react. While most arrhythmias are treatable if evaluated promptly by a doctor, some can lead to life threatening cardiac arrest.

If you see a doctor or go to the emergency room with RA symptoms, you may be hooked up to an EKG monitor to diagnose the type and severity of your arrhythmia.

An RA may be treated with medications and/or procedures designed to restore a healthy heart rhythm, such as:

Calcium channel blockers

These medications lower blood pressure and help blood vessels relax in order to promote better blood flow. They’re especially helpful in treating RAs because they help prevent calcium overload in your heart muscle’s cells.

One commonly used calcium channel blocker treatment is intracoronary verapamil. This is the injection of the calcium channel blocker verapamil directly into the affected artery within your heart.

Antiarrhythmic medications

These medications are used to help restore a normal rhythm to your heart if you have an arrhythmia. They change the electrical current or signal in your heart that regulates your heartbeat. Most of these medications are taken as pills.

The most common antiarrhythmic medications include:

  • amiodarone (Cordarone, Pacerone)
  • flecainide (Tambocor)
  • ibutilide (Corvert), which can only be given through IV
  • lidocaine (Xylocaine), which can only be given through IV
  • procainamide (Procan, Procanbid)
  • propafenone (Rythmol)
  • quinidine (many brand names)
  • tocainide (Tonocarid)

Other treatments include:

  • Cardioversion: During cardioversion, an electric shock is applied from outside your chest to reset a normal heart rhythm.
  • Catheter ablation: During catheter ablation, a group of cells in your heart that are causing the arrhythmia are destroyed.
  • Pacemaker: A pacemaker is an implanted device that uses mild electrical pulses to keep a healthy heart rhythm.
  • Implantable cardioverter defibrillator (ICD): An ICD is an implanted device that delivers an electrical pulse to your heart to help restore a normal heart rhythm.

A heart attack can cause damage to your heart’s muscle, valves, and electrical system. So simply having a blockage that’s opened up raises your risk of an RA or other type of arrhythmia.

Having had a previous arrhythmia may also increase your risk of having an RA.

Many RAs can be treated effectively and can resolve quickly without causing long-term problems. However, you may need medications or implantable devices to manage your heart rhythm for the rest of your life.

If you’ve had a heart attack or cardiovascular disease that’s been treated prior to an actual cardiac event, it’s important to have your cardiovascular health regularly monitored throughout your life. Advances in cardiac care continue to improve, and managing an arrhythmia of any kind is often doable with little impact on your longevity or quality of life.

Does the severity of a heart attack dictate the likelihood of an RA?

Not surprisingly, a major heart attack is associated with a greater risk of complications, including arrhythmia developing once a blocked coronary artery is reopened. Keep in mind that many people undergo reperfusion therapy after a severe heart attack without developing an arrhythmia.

Do all RAs require treatment?

Most RAs are transient and resolve on their own, with a healthy heart rhythm resuming soon after the arrhythmia first develops. When they don’t go away on their own, prompt treatment is necessary.

Does having an RA mean you will have other arrhythmias later on?

Your odds of developing an arrhythmia independent of your RA are higher, but it’s also likely that you won’t have future rhythm disturbances if you haven’t already been diagnosed with one. The key is to work with your cardiologist and monitor your heart rate, to catch any new arrhythmias before they become problematic.

Cardiac reperfusion can be a lifesaving treatment following a heart attack, but like many medical procedures, it’s not without risk. An RA is one of several potential complications relating to the restoration of blood flow in a previously blocked artery.

But, if you pay attention to potential symptoms of an RA and work closely with your cardiologist to treat it and manage the condition, you can usually recover and enjoy the benefits of renewed healthy circulation.