While no one particular heart rate qualifies as a heart attack, a rapid heart rate outside 60 to 100 beats per minute should be monitored closely.

Doctors cannot say that a particular heart rate qualifies as a heart attack. Your heart rate is not a reliable indicator that you are having a heart attack. It may become high or low or may not change at all.

A normal resting heart rate lies anywhere between 60 and 100 beats per minute. According to the American Heart Association, having a rapid heart rate is not a sign of a heart attack. However, if you feel faint and a flutter in your chest, you must call 911.

Your heart rate during a heart attack may be determined by factors that include:

• Underlying heart conditions: Certain problems in the right coronary artery can cause a slow heart rate during an attack.
• Medications: If you are on medications known as beta-blockers, which are typically given for hypertension and anxiety-related palpitations, you may have a lower heart rate during a heart attack.
• Tachycardia: If you have a condition that causes you to have tachycardia (a higher heart rate) even at rest, your heart rate may stay increased even during a heart attack.

What happens during a heart attack?

During a heart attack, blood flow to your heart gets restricted due to a blockage in an artery that supplies your heart. The blockage is typically due to a plaque, which is a fatty material that gets deposited on the inner wall of the artery.

In the absence of adequate blood flow to the heart muscles, these muscles are starved of oxygen supply and, therefore, can get damaged within a few minutes.

What are the symptoms of a heart attack?

The most common symptoms of a heart attack include:

• Chest discomfort in the form of sharp pain, tightness, or pressure on the chest
• Pain in one or both arms, chest, back, and jaw
• Shortness of breath
• Lightheadedness
• Sweating
• Nausea
• Pain in the upper abdomen, resembling peptic ulcer pain

What heart rate is an emergency?

At rest, your heart should not beat more than about 100 times per minute. If you develop a faster heart rate (tachycardia; in absence of known triggers such as high fever, vigorous physical activity, and panic attack), it’s an emergency. It can be a type of tachycardia known as supraventricular tachycardia, which can be life-threatening and precipitate in a heart attack.

Even an irregular heart rate or a pounding heart rate (palpitations) can be an emergency. If you feel that you are skipping a few beats in between when you feel your pulse, you may have an arrhythmia, which is a problem in the electrical activity of the heart.

Once you visit the emergency department, you will be administered medications that slow down your heart rate or those that make your heart rate beat at a regular rhythm.

When medications do not work enough, your doctor may attempt a procedure known as cardioversion that involves dispensing electrical shocks to the heart so that it can reestablish its rhythm.