What Is A Heart Attack Heart Rate?

What is a heart attack?

A heart attack usually occurs when the supply of blood flow is blocked by a blood clot in the heart. Without enough blood and oxygen, the heart can be seriously damaged. This can cause chest pain and many other symptoms, which can lead to cardiac arrest. Please seek medical attention immediately from a healthcare provider or professional if this is occurring to you or someone else. If the heart attack is not treated immediately, this can cause extensive heart damage. Typically a heart attack can last from 15 to 20 minutes; however, the buildup, symptoms and signs of a heart attack can start suddenly or unexpectedly.¹ 

Causes of heart attack

A common cause of heart attacks is due to coronary heart disease (CHD). CHD causes your coronary arteries to become narrow due to a gradual buildup of cholesterol or plaques. When a plaque bursts, a blood clot will form to repair the damage to the arterial wall, resulting in a partial or total obstruction. This will cause your heart muscle to be starved of oxygen and blood, triggering a heart attack.² Less common causes include spontaneous coronary artery dissection (SCAD), drug misuse and hypoxia (sudden drop in oxygen levels).¹

Types of heart attack

There are three types of heart attacks:

ST-segment elevation myocardial infarction (STEMI)

A STEMI is a very serious type of heart attack and this occurs when the blood supply is interrupted for too long. This can cause extensive damage to a large portion of the heart if the coronary artery is completely blocked.

Non–ST-segment elevation myocardial infarction (NSTEMI)

A NSTEMI is a less serious version of a STEMI, and this is due to a partial blockage in the coronary artery. Therefore, only a small part of the heart may get damaged. An NSTEMI is still considered a serious medical emergency; as without immediate treatment, it can progress into a STEMI.

Unstable Angina

An unstable angina is a very severe medical emergency as it can lead to heart damage or a STEMI. The blood supply to the heart is very much restricted, but there is no permanent damage, and the heart muscle is still preserved.² 

Symptoms of heart attack

The severity of the symptoms can depend on your age, gender and any existing medical conditions.

Symptoms to look out for:

1. Chest pain or any discomfort– this could appear as pressure/squeezing/heaviness in the chest, and it can feel like heartburn or indigestion. 
2. Pain spreading from your left to right arm and then to your neck, jaw, back and stomach. 
3. You may also experience nausea, sweating, dizziness, and shortness of breath.

Women are more likely than men to experience shortness of breath, nausea, vomiting and back and jaw pain. Less common signs and symptoms of a heart attack may include similar feelings of a panic attack like: 

• a sudden feeling of anxiety 
• excessive coughing or wheezing due to a buildup of fluid in the lungs 
• Fatigue
• lightheadedness
• sudden dizziness 

A combination of these symptoms may happen at the same time. Dizziness coupled with chest pain and shortness of breath may significantly lead to a decrease in blood volume and a drop in blood pressure, which could mean a heart attack is on the way. 

If you or someone else is experiencing these symptoms, please seek medical attention or contact a healthcare professional.¹ 

What happens during a heart attack?

1. Plaque formation: Blood vessel narrowing and oxygen deprivation occur when plaque forms inside blood vessel walls due to excess fat and cholesterol in the bloodstream. This is called atherosclerosis. 
2. Blood Clots Form: When a plaque in the coronary arteries ruptures, a clot is formed to repair the damage. This further damages the heart by either partially or completely arresting blood flow. This condition is called ischemia. 
3. Arterial Spasm: The heart's oxygen supply is interrupted as the coronary arteries spasm and constrict temporarily. This results in blocking the blood flow to the heart. 
4. Symptoms: You start experiencing chest pains, nausea, dizziness and other symptoms of a heart attack. 
5. Heart Releases Proteins: The proteins troponin T and troponin I are secreted into the bloodstream after heart cells are damaged during a heart attack. These proteins are detected from the blood test to confirm a heart attack. 
6. Damage Begins to Accumulate: The extent of the damage depends on the size of the blockage, its location within the heart, and how quickly it is opened. These three factors interact to determine how severe your heart attack will be.
7. Blood Pressure drops: The patient's blood pressure drops significantly. In the absence of oxygen, brain cells begin to perish, a process known as cerebral infarction. As a result, patients may experience vision loss, difficulty moving, and speech impairment. In severe cases, it can cause loss of consciousness, and cardiac arrest, a life-threatening condition in which the heart suddenly stops beating.

Change in heart rate during a heart attack

Differences between normal heart rate and heart rate during a heart attack

Normal heart rate

A normal heart rate for an adult is between 60-100 beats per minute (bpm). Heart rate differs among individuals; the healthier you are, the lower your resting heart rate (between 40-60 bpm).³ 

Heart rate during a heart attack

Your heart rate may increase, decrease or stay the same during a heart attack. This is due to the blockage in the coronary artery. Blood and oxygen supply to the heart organ will slow down, as without it the heart cannot function normally.

Types of heart attack and the heart rate

STEMI

Usually elevates the heart rate first and causes damage to the heart's electrical system resulting in slowing the heart rate down.

NSTEMI

Is when there is a partial blockage – this may be less damaging to the heart but can increase the heart rate due to an underlying issue like a fever.²

Reasons for the change in heart rate

A change in heart rate can be dangerous. Any variation from the normal rhythm in a heartbeat is called an arrhythmia. This condition occurs when the heart beats too slowly (bradycardia), too fast (tachycardia) or irregularly. Having an arrhythmia can be dangerous as it can cause dizziness, light-headedness and shortness of breath. It can increase the chances of a stroke and heart attack.

Is change in heart rate a reliable indicator of a heart attack?

A change in heart rate is not a reliable indicator of a heart attack, as an elevated heart rate is not always a sign of a heart attack.

Reliable tests or indicators of heart attacks include:

1. Blood tests: A blood sample will be taken to check for cardiac markers (heart proteins). Blood tests will be done over a few days, which will allow the damage to your heart to be assessed.
2. Chest X-rays can be done to check for complications because of the heart attack or other possible causes of your symptoms.
3. An echocardiogram scans your heart and builds a picture to identify areas that have been damaged.⁴ 
4. Coronary angiography can help find blockages and narrowing in the coronary arteries, which can help decide what treatment is best for you. 

Can medications affect heart rate during a heart attack?

Beta-blockers are a common medication that reduces the workload of your heart. This medication is inexpensive and saves lives by lowering your heart rate and blood pressure. If your heart is weak, certain beta blockers can help protect your heart and make it stronger.⁵ 

Other medications that affect the heart rate

Other medications such as prescription drugs, non-prescription drugs, inhalers, creams or ointments, vitamins, supplements, and herbal remedies can stop your heart medicine from working properly.⁵ 

Change in blood pressure during a heart attack

Normal blood pressure and blood pressure during a heart attack

Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood around the body. Ideal blood pressure would be 120/80 mmHg for any individual. 

Blood pressure during a heart attack will increase significantly. 

Around 50% of heart attacks and strokes are associated with high blood pressure. The function of the heart is to pump blood all over the body. If you have high blood pressure, the arteries are designed to stretch to cope with rising blood pressure; but if those arteries get damaged and clogged, it can lead to a heart attack.

Blood pressure may also decrease during a heart attack. The parasympathetic nervous system may go into overdrive during a heart attack because of the decreased blood flow to the heart as a result of tissue damage brought on by pain, particularly in the chest.⁶ 

When to contact a doctor

If you experience any of the symptoms of a heart attack, it is absolutely essential that you contact an emergency service or a healthcare provider immediately. The quicker the response time to help those who are experiencing symptoms of a heart attack, the less heart damage will occur. In the event that your heart stops beating, an ambulance or paramedic can begin treatment right away as they are trained to do so.

Summary

Depending on whether your coronary artery is partially or completely obstructed, your heart rate during a heart attack may be the same as normal or may increase slightly. If you’re experiencing a heart attack or chest pain, seek medication treatment immediately. The more severe the heart attack, that is, the larger the blockage, the longer it takes to treat the condition. Seek medical attention immediately if you experience chest pain or other symptoms, and you may reduce the severity of the damage to your heart.