Someone’s heart rate can increase or stay the same during a heart attack. An elevated heart rate is not a specific sign or symptom of a heart attack.

Heart attacks involve a restriction or stoppage of blood flowing to the heart. A person’s heart rate during a heart attack will vary based on their overall health, medication use, and other medical conditions.

Some people will experience an increased heart rate during a heart attack, but others will not. More common signs of a heart attack include severe chest pain, shortness of breath, and tightness in the chest.

This article discusses what happens during a heart attack, how it affects the heart rate, and what to do.

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A heart attack occurs when the heart loses all or some blood flow to the organ. The blood flowing to the heart provides oxygen. Without oxygen, the heart cannot function normally.

According to the American Heart Association, the heart becomes damaged during a heart attack. The amount and severity of damage will depend on:

  • how much of the blood flow to the heart is blocked
  • what the oxygen demand of the heart muscle is
  • the speed of treatment

Following a heart attack, the heart will begin to heal, sometimes creating scar tissue over the damaged area. In some cases, the heart will become permanently weakened and pump less blood.

A person’s heart rate may increase or stay the same during a heart attack.

The heart rate at the time of treatment can sometimes predict recovery success. According to one 2018 study across 58 hospitals, a heart rate above 80 beats per minute had the highest risk of mortality following a heart attack.

Is a high heart rate a sign of a heart attack?

An elevated heart rate is not a reliable sign of a heart attack.

The Centers for Disease Control and Prevention (CDC) and American Heart Association do not recognize heart rate elevation as a sign or symptom of a heart attack.

There are three types of heart attack, each of which affect heart rate differently. The three types are:

  • ST-segment elevation myocardial infarction (STEMI)
  • non-ST segment elevation myocardial infarction (NSTEMI)
  • coronary artery spasm

STEMI can be the most severe form of heart attack. It typically causes an elevated heart rate during the event but certain types of STEMIs can cause damage to the electrical system of the heart and slow the heart rate. NSTEMI heart attacks are usually less damaging to the heart, but may also increase the heart rate. Sometimes the NSTEMI (Type II) is a result of fast heart rate as a result of some other underlying issue (fever, bleeding) with a fixed blockage of the coronary arteries.

Coronary artery spasms occur when the artery walls tighten and restrict blood flow to the heart. They can also affect the heart rate.

Heart attacks cause damage to part of the heart. The damage occurs in any area that the blocked artery usually supplies with blood.

According to the American Heart Association, a damaged heart will keep pumping blood through the body, but the effort may weaken it. During the event, a person’s heart rate can increase.

A doctor or emergency room team may use a beta-blocker to slow the heart rate, reducing the oxygen demand of the heart. This can help prevent further damage to the organ.

According to the American Heart Association, tachycardia is where a person’s heart rate is too fast for their age and overall physical condition. During a heart attack, their heart rate will likely remain elevated.

Bradycardia causes a slower heart rate. People with bradycardia or other diseases of the electrical system may not experience an increased heart rate during a heart attack.

The American Heart Association states that during a heart attack, the heart muscle will suffer damage due to a lack of oxygen. This can weaken the heart, which can cause blood pressure to drop during or following a heart attack. Low blood pressure can compromise the blood flow to the heart.

Stress during a heart attack can also increase blood pressure. Once treatment has begun, healthcare professionals will monitor blood pressure and stabilize it as needed. Higher blood pressure can increase the oxygen demand of the heart.

There are several potential signs of a heart attack to look out for, including:

  • discomfort in different areas of the body, such as in one or both arms, the neck, back, or stomach
  • pressure or fullness in the chest
  • chest discomfort or shortness of breath
  • lightheadedness
  • nausea
  • cold sweat

Symptoms can vary based on whether a person is male or female. Everyone may have chest pain or fullness. Females are more likely to experience some of the other atypical symptoms, such as discomfort around the body.

About 50% of all Americans have at least one risk factor for a heart attack. According to the CDC, some common risk factors include:

  • family history of heart disease
  • smoking
  • high blood pressure
  • high cholesterol
  • older age

Anyone experiencing symptoms of a heart attack should contact emergency services immediately. The CDC states that early treatment reduces the chances of permanent damage or fatality.

Following the emergency, a person should follow up with their doctor for steps to support a full recovery. Doctors will typically help develop a follow-up treatment plan that may include preventive medicine and lifestyle changes.

A person’s heart rate during a heart attack may increase or stay the same, although an elevated heart rate may be associated with a worse outcome. Doctors may provide medication during a heart attack to lower the heart rate, such as beta-blockers.

An elevated heart rate is not a reliable sign of a heart attack. Pay attention to other signs, such as chest pain, pressure, or discomfort. A person should contact emergency services immediately if they are experiencing any signs of a heart attack.