What is a Heartbeat?
It is a kind of ‘vital sign,’ or an important indicator of health in the human body. By knowing about heartbeat we can measure the number of times per minute that the heart contracts or beats.
There is variation in the speed of heartbeat because of physical activity, threats to safety, and emotional responses. Whereas when a person is in a relaxed state it is called a resting heartbeat. In case any individual has a normal heart rate, it does not guarantee that a person is free of health problems, it is a useful benchmark for identifying a range of health issues.
Functioning of Normal Heart
The process of plumbing of the heart is done by a series of electrical impulses produced by a bunch of special cells in the right atrium, called the sinus node. As such, the sinus node is called a “ natural pacemaker.” Production of pulses of electrical activity that spread through the heart’s cells is done by the sinus node which causes the heart muscle to undergo a contraction process.
The movement of an electrical impulse through the heart is like the travelling of electricity through a circuit of fine wires. Impulses which are generated through sinus nodes travel down through the atria to special cells in the AV node. These impulses make atria contract and this process leads to the squeezing of blood into the ventricles.
Further, there is a transfer of impulse from the AV node through the ventricles via an electrical pathway. And these electrical impulses cause the ventricles to contract and squeeze the blood out of your heart to your body and your lungs.
What is the Difference Between Heartbeat and Heart Rhythm?
The number of times the heart beats in a minute is called heartbeat. It is also the number of times the heart pumps to push blood around the body.
The pattern in which the heart beats is called heart rhythm. It may be regular or irregular, or fast or slow depending upon the function of the heart.
Normal Heart Rhythm
The normal rhythm of the heart is called “sinus rhythm.” In normal rhythm, the heartbeat varies from 60 and 100 beats per minute (bpm) while you are resting. In the case of slower sinus rhythm, the heartbeat is about 60bpm which is called sinus bradycardia and if sinus rhythm is faster then it is called tachycardia and this heartbeat is 100bpm. There is variation in the heartbeat minute to minute depending on the need and functioning of the heart.
All conditions like sinus rhythm, sinus bradycardia, sinus tachycardia and sinus arrhythmia are all normal heart rhythms where the electrical impulses travel in a normal way through the heart.
Echocardiogram
Ultrasound scanning of the heart is called electrocardiograph and this technique is not at all uncomfortable. This test can be done within an hour. By this, we can detect if one has a problem with his/her heart muscle or heart valves, which could be the cause of arrhythmia.
Interesting Facts About Heartbeat
A. Number of times the heart beats per minute is the measurement of the heart functioning.
B. The heart rate of a person should be between 60 and 100 beats per minute while they are resting after the age of ten years.
C. There is an increase in the heartbeat during exercise.
D. Irregular heartbeat causes several heart problems.
E. As per current data, one in every four deaths in the United States occurs as a result of heart disease. So, proper monitoring of your heart rate can help prevent heart complications.
FAQs on Heartbeat
1. What is a heartbeat and how is it typically measured?
A heartbeat is a single, complete contraction and relaxation of the heart muscle, a process that pumps blood throughout the body. It is measured as heart rate, which is the number of times the heart beats per minute (bpm). For a resting individual, this can be easily measured by checking the pulse at the wrist or neck.
2. What is a normal resting heart rate for a healthy adult according to the CBSE curriculum?
As per the CBSE 2025-26 syllabus guidelines for Biology, a normal resting heart rate for a healthy adult or a teenager over 10 years old typically falls within the range of 60 to 100 beats per minute (bpm). A heart rate of approximately 72 bpm is often considered the average.
3. What is the fundamental difference between heart rate and heart rhythm?
While often used interchangeably, these terms describe different aspects of heart function. Heart rate is the speed of the heartbeat, measured in beats per minute (bpm). In contrast, heart rhythm refers to the pattern and regularity of those beats. A healthy heart has both a normal rate and a steady, consistent rhythm, known as 'sinus rhythm'.
4. Why is the human heartbeat described as 'myogenic'?
The human heartbeat is called myogenic because the electrical impulse that initiates the contraction originates from specialised muscle tissue within the heart itself, rather than from an external nerve stimulus. This intrinsic electrical activity is initiated by the sinoatrial (SA) node, making the heart's ability to beat self-contained.
5. How does the SA node function as the heart's 'natural pacemaker'?
The sinoatrial (SA) node, a cluster of specialised cells in the right atrium, spontaneously generates electrical impulses. These impulses spread across the atria, causing them to contract and push blood into the ventricles. This signal then travels to the atrioventricular (AV) node, which coordinates the contraction of the ventricles, thereby setting the pace for the entire cardiac cycle.
6. What do the 'lub' and 'dub' sounds of the heartbeat signify?
The two primary heart sounds, 'lub' and 'dub', correspond to the closing of the heart valves during the cardiac cycle:
- The first sound, 'lub' (S1), is produced by the closure of the tricuspid and mitral valves when the ventricles begin to contract.
- The second sound, 'dub' (S2), is produced by the closure of the aortic and pulmonary valves after the ventricles have ejected blood.
7. Can a person have a normal heart rate but still have an underlying heart problem?
Yes, it is entirely possible. A normal heart rate (e.g., 70 bpm) only measures the speed of contractions. A person could still have a serious issue such as an abnormal heart rhythm (arrhythmia), a faulty heart valve, or weakened heart muscle. Therefore, a normal heart rate does not guarantee the absence of cardiovascular problems.
8. Compare tachycardia and bradycardia. Are these conditions always a sign of disease?
Tachycardia and bradycardia are terms that describe the rate of heartbeat:
- Tachycardia refers to a heart rate that is too fast, typically over 100 bpm at rest.
- Bradycardia refers to a heart rate that is too slow, typically below 60 bpm at rest.
