Normal Resting Heart Rate and All About Heart

Introduction

The heart is the powerhouse of the circulatory system. It circulates blood consistently throughout the body, supplying the other organs with oxygenated blood and nutrients and returning the deoxygenated blood to the lungs. The heart is a muscular organ and comprises a total of four main chambers. They are atria (two upper chambers) and ventricles (two lower chambers), one of each present on either side of the heart. The atria help the ventricle fully load up before it ejects blood from the heart. The heart’s valves work together, ensuring oxygenated blood is delivered throughout the body. The sound of the heart beating can be attributed to the closing of the valves.

What Is a Heartbeat?

The various heart chambers expand and contract, or tighten and relax, as the heart pumps blood. A thumping sound is produced each time the chambers tighten or loosen, and this is what is known as the heartbeat. It indicates the end of a complete cycle of blood pumping. Usually, a healthy heart beats seventy-two times per minute, and in each heartbeat, about 55 to 80 ml of blood is pumped. A heartbeat is a two-part, second-long pumping motion. First, the sinoatrial node (the heart’s natural pacemaker) releases an electrical signal that forces the upper chambers (the right and left atria) to contract as blood builds up. Then, through the tricuspid and mitral valves, this contraction forces blood into the lower chambers (the right and left ventricles), which are at rest. Diastole refers to the first of the two pumping phases and is the longer of the two.

As soon as the ventricles are filled with blood, the second phase of the pumping starts. The ventricles contract due to the electrical signals sent from the SA node through a network of cells and fibers. This second phase is referred to as systole.

What Is a Normal Resting Heart Rate?

A heart rate is defined as the number of times per minute the heart contracts, pushes blood through the body, and generates a pulse. In the case of a normal resting heart rate, the heart pumps the least quantity of blood when the body is at rest to meet its oxygen requirements.

What Are the Factors Affecting the Normal Resting Heart Rate?

The following factors can affect the resting heart rate:

• Weather Conditions - Pulse may increase with increased temperatures and humidity levels.

• Change in Posture - Simply standing up or changing the posture can spike the resting heart rate for the first twenty seconds and then normalize.

• Anxiety or Stress - Emotional distress is associated with changes in heart rate.

• Age - Children have faster rates than adults, while infants have a faster rate than children. The heart rate is fastest in life at nine to ten weeks after conception, when the average rate tops at around 170 to 180 beats per minute. Then, over the next several weeks, the pace slows down until settling out somewhere between normal ranges. Usually, the resting heart rate per minute does not get affected by an increase in age, but with an increase in age, on exercising, it takes longer for the heart rate to increase and longer for it to normalize afterward.

• Weight - The resting heart rate is typically higher in overweight individuals.

• Sex - On average, the resting heart rate of women tends to be higher than men (anywhere between two and seven beats per minute higher).

• Caffeine and Nicotine - Caffeine and nicotine act as stimulants and raise the heart rate.

What Is the Significance of a Resting Heart Rate (RHR)?

The resting heart rate (RHR) provides a rough snapshot of the health of the myocardium (cardiac muscle or heart muscle). If tracked daily, it can help make timely interventions when the levels drop or rise. A slow heartbeat is not something to be worried about always. A resting heart rate between 40 to 60 beats per minute is quite common during sleep in healthy young adults and elite athletes. As one gets fitter, the resting heart rate value will decrease, and it is possible to train the heart through cardiovascular exercise such as running. After all, just like any muscle, the heart muscle can be strengthened with exercise.

Higher levels of resting heart rate could be indicative of the following:

• Excess stress levels.

• Excess levels of caffeine or nicotine.

• Sign of infection.

If none of those mentioned above are involved, a higher resting heart rate could also be a sign of heart arrhythmias or other heart conditions.

What Happens When the Heart Rate Does Not Fall Within Its Normal Ranges?

Resting heart rates for most healthy adults and women range from 60 to 100 beats per minute. When the heart rate is above 100 beats per minute, it gives rise to a condition called tachycardia, and if the heart rate falls below 60 beats per minute, it gives rise to a condition known as bradycardia.

What Is Tachycardia and Its Different Types?

Tachycardia is an abnormally fast heart rate (more than 100 beats per minute). There are three types of tachycardia. There are three types of tachycardia:

Atrial or Supraventricular Tachycardia (SVT) - It is a fast heartbeat that starts within the heart’s upper chambers. The electrical signals within the heart’s upper chamber fire irregularly and abnormally, impeding electrical impulses from the sinoatrial (SA) node -the heart’s pacemaker.

Sinus Tachycardia - It refers to the normal increase in heart rate and occurs due to a malfunction within the sinoatrial (SA) node. The heart’s natural pacemaker sends signals faster than usual. Although the heart rate is faster than normal, the heart beats properly. The causes of sinus tachycardia are as follows:

• Anxiety.

• Fright.

• Severe emotional distress.

• Strenuous exercise.

• Fever.

• Anemia.

• Damaged myocardium (heart muscle).

Ventricular Tachycardia - It refers to an increase in heart rate due to abnormal signal conduction within the heart’s ventricles (lower chambers).

What Is Bradycardia?

Any heart rate lesser than 60 beats per minute gives rise to a condition called bradycardia.

When the heart rate is slow, it does not pump blood efficiently to the rest of the body. The causes of bradycardia are:

• Hypothyroidism.

• Heart tissue damage due to inflammation or injury.

• Congenital heart defects.

• Inflammatory diseases such as rheumatic fever.

• Medications such as Opioids.

• Electrolyte imbalance in the blood.

How Is Resting Heart Rate (RHR) Measured?

In order to work out the heart rate, the following method can be used:

• Manual Method - The resting heart rate can be measured manually or the old-fashioned way by checking the pulse while the person is at rest or sitting still. With the help of the middle and index fingers placed between the tendon and bone over the radial artery (which can be found on the thumb side of the wrist), the pulse or throbbing can be felt. Count the number of beats in fifteen seconds and multiply it by four. The resultant number would indicate the resting heart rate per minute. It can also be checked over the artery that runs on the neck (like with the wrist). Place the thumb and middle fingers on the side of the windpipe and count the beats per minute.

• Using a Smartwatch or Technical Application - With the help of a smartwatch or a mobile application, an individual can track, measure, and track their heart rate. The good thing about the heart rate data from the smartwatch is that it provides long-term data. So, although the numbers may not be accurate in themselves, the trends from the data over time can indicate changes in the heart rate. For example, keeping track of the resting heart rate first thing in the morning can help spot early signs of illness, overtraining, or general tiredness.

How Can the Resting Heart Rate (RHR) Be Lowered?

Resting heart rate can be modified and lowered by the following measures:

• Exercise - On exercise, the heart beats faster and continues doing so for a little while, even after the physical activity ceases. As the heart is used more in the way, it gets stronger.

• Adequate Hydration - When the body is provided with plenty of fluids in the form of water or juices, it helps the heart’s functioning. Dehydration causes the blood to thicken, which taxes the heart as it becomes difficult to push and pump blood forwards.

• Avoiding Caffeine and Nicotine - These stimulants elevate the resting heart rate. Studies show that smokers have a higher resting heart rate.

• Losing Weight - When the individual is overweight, the heart needs to put more effort into supplying the body with blood.

• Reducing Stress - Studies show that relaxation techniques such as yoga and meditation can aid in decreasing an elevated resting heart rate.

Conclusion

The pace at which a person’s heart beats while at rest is known as the resting heart rate. When a person does not move or exercise, the heart pumps the least amount of blood for the body to survive and be fueled. The typical resting heart rate varies and ranges from 60 and 100 beats per minute. Typically, it is lower for those who exercise frequently and greater for those with a sedentary lifestyle. Additionally, the resting heart rate increases with an increase in age or when an individual has any illness or stress. When tracked daily, it can help make timely interventions when the levels drop or rise.