Is a Strong Heartbeat Good?

Introduction

Is a strong heartbeat good? What does it mean when your heart beats fast or slow? Continue reading to find out what you need to know about your heartbeat.

Every hour, minute and second of the day, our heart is beating away below our sternum; depending on what we are doing, our heartbeat increases or decreases in response to our body’s requirements. The heartbeat is the engine that keeps the body functioning and moving, thus, essentially keeping us alive. A heartbeat is triggered by electric signals that travel through the heart from the top to the bottom. A single heartbeat takes 1 second and is made up of two phases: diastole and systole.

Blood Flow in the Heart

During the diastole phase, when blood fills up the right and left atrium (the upper chambers of the heart),  an electrical signal is fired by the sinoatrial node (the heart’s natural pacemaker). This causes the atria to contract and force blood into the left and right ventricles (the lower chambers of the heart) through the tricuspid and mitral valves. These valves ensure the blood flows in the correct direction and stops backflow. The signal from the sinoatrial node then travels to another group of pacemaker cells called the atrioventricular node, which slows the signal before it reaches the ventricles. This allows time for the atria to fully contract and the ventricle to finish filling before the ventricle contracts. Along the ventricular walls, a complex network of fibres called the His-Purkinje network receives the electric signal from the atrioventricular node, which causes the ventricles to contract and pump blood through the aorta out of the heart. Once the blood is out, the ventricle relaxes and the cycle begins again, starting with the sinoatrial node.¹

Heart as Cardiac Muscle

Unlike most muscles in our body, such as the biceps, quadriceps and abdominals, our cardiac (heart) muscle contracts without the need for conscious control (i.e. it functions automatically). However, though the heart muscle (cardiac muscle) may differ from other muscles in some aspects, similar to most muscles, the cardiac muscle can be trained to increase in size. When we exercise, our heart rate increases to pump more blood around the body, and with regular exercise, our cardiac muscle adapts to the stress exercise caused by increasing in size. This allows the cardiac muscle to pump more blood around the heart at a lower heart rate, whereby the cardiac muscle essentially becomes stronger and more efficient.²

According to NHS England, an average resting heart rate should range between 60-100 beats per minute, and fitter individuals would likely have a resting heart rate between 40-60 beats per minute. Additionally, they suggest that if your heart rate is continuously above 120 or below 60 beats per minute, you should contact your GP.

What can a strong, fast heartbeat indicate?

High Blood Pressure

An elevated resting heart rate can be an indication of high blood pressure.   A blood pressure monitor can provide a reading of your blood pressure, and the results will be in the form of 2 numbers (e.g. 120/80 mmHg). The first figure (in this example 120) is the systolic pressure, which is the pressure in the arteries when the ventricle contracts and pumps blood around the body. The second figure (in this example 80) is the diastolic pressure, which is the pressure in the arteries in between beats before the sinoatrial node triggers the heart to contract again.  According to NHS England, the ideal blood pressure should range between 90/60 mmHg and 120/80 mmHg, and you are considered to have high blood pressure if your reading is above 140/90 mmHg. High blood pressure (or hypertension) is linked to an increase in the risk of cardiovascular diseases; with research showing for every 10 beats per minute increase in resting heart rate, the risk of cardiovascular disease development increases by 15% and all-cause mortality increases by 17%.³  

Fever

An increase in resting heart rate can also be an indicator of fever. In response to infections, our body produces white blood cells, which help fight off foreign cells in the body. However, an increase in white blood cells in the blood can affect our hypothalamus (a region in our brain that regulates our body temperature). Thus, to fight off infections, white blood cells are released, which causes our body to rise in temperature, leading to the development of a fever.⁴ With every 1°C increase in body temperature, our heart rate increases by 8.5 beats per minute.⁵ This occurs because our body is trying to emit heat from the body through blood flow in our arteries and veins, and by increasing our resting heart rate, the amount of blood that circulates through the body increases.⁶

Weak Heart Muscles

As mentioned earlier, the cardiac muscle is a trainable muscle that can increase in size. A strong heart can pump more blood around the body at a lower heart rate, whereas a weaker cardiac muscle would need to beat more times per minute to supply the body with the required amount of blood since it pumps less blood per beat. 

Exercise

Last but not least, a strong and fast heart rate can simply be an indicator that you are partaking in exercise; may that be a long walk, jog or a single sprint, our heart rate increases to accommodate the increased oxygen demand by our muscles. During moderate-to-vigorous exercise, our body can require up to 35 times the amount of oxygen needed at rest. Heart rate increases proportionally with exercise intensity until the maximal heart rate is reached.⁷

Signs of a Healthy Heart

1. Low Resting Heart Rate

You have a resting heart rate between 60-100 beats per minute. If you exercise regularly, your heart rate may be as low as 40 beats per minute, which can indicate you have excellent cardiovascular health.

2. Normal Blood Pressure

You have a blood pressure reading between 90/60 mmHg and 120/80 mmHg. Blood pressure in this range indicates that the blood pumped out by the heart is pushing against the walls of your arteries with a normal force. Thus, you are at a lower risk of developing cardiovascular diseases such as hypertensive heart disease, hypertension and atrial fibrillation.  

3. High Energy Level

You are energetic and very active. When your heart is functioning as it should be, your body will be supplied with enough oxygen and nutrients it needs to provide you with energy to be active. If you constantly feel fatigued, this could be a sign that your heart is not pumping enough blood to supply the rest of your body with the required oxygen and nutrients.

4. Normal Cholesterol Levels

Your cholesterol levels are within the normal range. NHS England’s guide indicates that total cholesterol levels should be less than 5 mmol per litre, with HDL (i.e. ‘good’ cholesterol) levels above 1 mmol per litre and LDL (i.e. ‘bad’ cholesterol) levels below 3 mmol per litre.

5. Speedy Recovery Rate

Your heart rate returns to your normal resting heart rate quickly following intense exercise. You can test this by yourself by counting your heart rate per minute immediately after exercising for a few minutes. If your heart rate decreases by 20 beats per minute, it can indicate that you have a healthy heart.

6. Normal Breathing

You are not out of breath whilst doing regular daily tasks, such as walking your dog or gardening. When you exercise, your muscles require more oxygen to function. However, during light exercise, if your breathing remains relatively normal, it can indicate that you have a healthy and strong heart that supplies all the oxygen your muscles need to perform these activities.

Summary

Our heartbeat can tell us many things about our health. A single heartbeat consists of two phases: diastole and systole. During the diastole phase, the atriums fill up with blood and are forced into the ventricles by a contraction triggered by electric signals fired from the sinoatrial node. The signal then travels through the atrioventricular node towards the His-Purkinje network, located along the ventricular, causing the ventricular chambers to contract and pump blood through the aorta into arteries and veins leading to the rest of the body. A strong, fast heart rate can indicate many things, including high blood pressure, fever, weak heart muscles, or simply just that you are exercising. Lastly, you have a healthy heart if you have a low resting heart rate, normal blood pressure levels, high energy levels, normal cholesterol levels, speedy recovery rate following exercise and normal breathing patterns during light exercise.