A normal heartbeat has a resting rate of between 60 and 100 beats per minute. Your heart is made up of four chambers: two upper chambers (atria) and two lower chambers (ventricles). Located in the right atrium is the sinus node, which acts as a natural pacemaker and controls the rhythm of your heartbeat by producing electrical impulses. The electrical impulses have to travel from the sinus node, across the atria, through the atrioventricular node, and into the ventricles. Therefore, if there is ever a problem with the function of any of the chambers that make up your heart, it will affect the rate of your heartbeat, resulting in an arrhythmia.
If your heart rate is too fast, this is referred to as tachycardia. If your heart rate is too slow, this is called bradycardia. There are many things that could affect your pulse to be higher or lower than normal. They include:
- Being an athlete: Conditioned athletes will commonly have a heart rate that is less than 60 beats per minute because their hearts are so efficient.
- Premature heartbeat: While this feels like our hearts may have skipped a beat, a premature heartbeat is actually caused by an extra beat. If you feel occasional premature heartbeats, this usually is completely normal and does indicate a more serious problem.
- Ingesting stimulants: Stimulants such as caffeine or nicotine can cause your heart to beat faster and are the most common cause of premature heartbeats. If you use stimulants like these often, they could contribute to the development of more serious types of arrhythmias. Other stimulants include over-the-counter or prescription cough or cold medicines as well as illegal drugs such as cocaine or amphetamines. Consistently using drugs like these could have severe consequences on your heart and lead to many different types of arrhythmias or even sudden death from ventricular fibrillation.
- Drinking too much alcohol: If you drink a lot of alcohol, this could affect the electrical impulses in your heart, which can in turn affect your heart rate and pulse. Consistently drinking too much alcohol over a long period of time can also increase your chance of developing atrial fibrillation, which is a type of arrhythmia.
- Electrolyte imbalance: Potassium, calcium, magnesium, and sodium are all substances found in your blood that are called electrolytes. They are called this because they help to trigger and conduct the electrical impulses that make your heart beat. If your electrolyte levels are too low or too high, this could contribute to a slower or faster heart rate than normal.
- Heart problems: If were born with a heart abnormality, this could affect the rhythm of your heart. Other heart problems such as coronary artery disease, narrowed heart arteries, heart attack, cardiomyopathy, or previous heart surgery can also cause damage to your heart and contribute to the development of some types of heart arrhythmias.
- Other health conditions: High blood pressure can cause the walls of your heart to become thick and stiff, which will change how the electrical impulses are able to travel through your heart and lead to a change in your pulse. Other health conditions that can contribute to a pulse that is higher or lower than normal could include thyroid problems, diabetes, and obstructive sleep apnea.